Monday, December 29, 2008

Alberta clipper threatens snow for New Year's Eve/Day

Another Alberta clipper system is forecast to spread an area of snow across southern Manitoba Wednesday evening reaching Winnipeg sometime Wednesday night, just as we usher in the new year.  The snow is expected to continue into Thursday morning before tapering off by afternoon.  Early snowfall projections with this system are in the 5-10 cm range. Note that the system will also be accompanied by brisk southeast winds ahead of it Wednesday evening, and gusty northwesterly winds behind it on Thursday, so blowing and drifting snow may be a problem in addition to the snowfall.       

Thursday, December 25, 2008

Some snow on the way as cold snap eases..

The cold weather of the past 2 weeks will finally be loosening its grip over southern MB over the next few days with temperatures rising to normal values for late December. The milder temperatures will be ushered in with occasional snow bearing systems moving across the southern Prairies, both tomorrow (Friday) and Sunday. Friday's system will be a developing low across the Dakotas that will spread snow into southern MB Friday into Friday night. Amounts with this system look to be around 5 cm for most localities in southern MB, possibly up to 10 cm in some localities. Brisk northerly winds behind the system may produce areas of blowing and drifting snow Friday night. An Alberta clipper will threaten another 5-10 cm of snow to southern MB late Sunday into Monday morning.

Season's Greeting from Rob's Obs

Carol of the Bells - Computer Controlled Christmas Lights from Richard Holdman on Vimeo.

Tuesday, December 23, 2008

College of DuPage server problems

Links through College of DuPage are currently unavailable due to server problems. They hope to have it up and running soon. Until then, access to warnings and some satellite photos on my website will not be working properly. EC warnings can be found through the Weatheroffice website.

Friday, December 19, 2008

Snowfall warning issued for areas near the US border - Winter Storm Warnings south of the border

A storm system moving across the Northern Plain states is spreading an area of snow through North Dakota  and southwest MB today. This area of snow will slowly move eastward tonight and persist through Saturday and Saturday night over North Dakota and southern MB. A snowfall warning has been issued for areas along the US border from Killarney through Emerson to Steinbach and Vita for up to 15 cm of snow by Saturday evening. Here in Winnipeg, we will still see snow out of this system tonight and Saturday, with amounts up to 10 cm expected by Saturday evening.   

Once again, conditions are expected to be worse south of the border. Like last weekend, this will mean difficult travel conditions if you're heading into North Dakota or northern Minnesota, although this event should not be as severe as last weekend's blizzard in those areas.   Nevertheless, winter storm warnings have been issued for North Dakota and northern Minnesota for snowfalls of 15 to 25 cm tonight through Saturday along with gusty winds and blowing snow through Saturday night.  People planning to travel to the States this weekend should be prepared for poor driving conditions and allow extra time to reach their destination.  

Wednesday, December 17, 2008

A respite from wind chill

The cold is here to stay for awhile, but at least the wind is nice and light today which will make those -20ish temperatures more bearable. In fact, with bright sunshine and afternoon highs near -21C, it won't feel too bad at all out there today. For tonight, a weak system from Alberta will cross southern MB bringing some light snow to the area, with a dusting to 2 cm possible in most localities including Winnipeg. Behind the system, northerly winds of 20 km/h will develop for Thursday, with temperatures in the mid minus 20s producing windchills in the minus 35 to minus 38 range (still shy of -40 warning level) Winds should drop off again Friday so windchills warnings may not be necessary for the rest of the week over much of southern MB. On Saturday, a storm system over the central Plains will bring an area of snow over the Dakotas into southern MB. Like last weekend's storm, the bulk of the snowfall with this next storm system is expected to remain south of the border, however it's possible parts of southern MB could see 5-10 cm on Saturday. Unfortunately, gusty northerly winds are forecast behind this system for Sunday with temperatures in the mid minus 20s and windchills likely in the -40 to -45 warning range again. Below normal temperatures are expected to continue through the first part of next week, with models hinting at some moderation by Christmas.

Note that Winnipeg has had a daily maximum temperature below -20C since Sunday Dec 14th. With forecast highs below -20C for the next 5 days, it's possible we may go 10 straight days before we crack the -20C mark again. This would be the longest such streak for a December in recent memory. (longest -20C streak for a December in Winnipeg was 15 straight days from Dec 11-25 1879, during Winnipeg's coldest December on record)

Monday, December 15, 2008

There's cold..then there's real COLD!

Yes it's cold here.. but we're not the only ones suffering through frigid temperatures. The cold weather has flooded much of western Canada and the northern States with well below normal temperatures. Even the balmy west coast is shivering through subfreezing temperatures, with Vancouver expected to remain below freezing for the next week. And if you really want to see cold.. check out Siberia. Verkoyansk was a brutal -56C this morning (actual air temperature, not windchill) with plenty of -50C readings across Siberia. Makes that -30C feel downright balmy, eh? Finally, it's always an interesting read to see what real cold weather is like. Check out this interesting article, Life at Minus 80, about the day Snag, Yukon hit -62C (-81F) on February 3rd, 1947.. North America's coldest temperature on record. Don't you feel warmer now?

Wind chill.. Get used to that term..

OK, OK.. so we're all complaining about the cold. And it looks like we'll be stuck with it for awhile (possibly through the end of December) so we might as well get used to it (or leave if you're lucky enough) The main issue over the next week or two will be the wind.. which will determine whether or not windchill warnings are required. Environment Canada issues windchill warnings when the windchill is forecast to reach or exceed -40 for at least 3 hours, with a windspeed of at least 11 km/h. This week, with high temperatures around -25C, and low temperatures in the -30 to -35C range, it won't take much wind to reach those windchill warning levels. At -30, you need a windspeed of only 11 km/h to produce a windchill of -40. At -25C, you need a sustained wind of at least 33 km/h to produce a windchill of -40. These values look likely tonight into Tuesday, but winds may be light enough by Wednesday so that windchill may not be an issue (though it will still be cold) Wind speeds may pick up again in the 15-25 km/h range for the end of the week.

Remember that windchill is not an actual temperature, but rather a measure of the cooling rate of the atmosphere based on the temperature and windspeed. Your body loses heat more quickly when a wind is present.. the faster the wind, the more rapidly you lose heat. For more details on this windchill issue, read my entry from last winter explaining the windchill factor.

Sunday, December 14, 2008

Southern MB dodges blizzard.. but not bitter cold

A strong winter storm system passing through the northern Plains has spared much of southern MB from significant snow or blizzard conditions, but not from bitter cold temperatures and extreme windchills. The storm, centered over southern Minnesota this morning, has brought snow and blizzard conditions to much of North and South Dakota overnight which will continue into today. Areas of southern MB near the ND/MN border from Emerson to Sprague will still see some snow with this system today (perhaps 2-4 cm), with locally poor visibilties in blowing and drifting snow especially in the southern Red River valley, but blizzard conditions are expected to remain south of the border.

The main story over the next few days will be the bitter cold, with strong winds today producing extreme windchills of -40 to -45. At these values, frostbite is possible within 10 minutes. Winds will ease somewhat Monday and Tuesday, but with bitter cold temperatures continuing (-25 to -35C), wind chills will be an issue through much of the week.

Friday, December 12, 2008

Major winter storm to affect southern Prairies/northern Plains this weekend..

A strong storm system pushing into southern BC today will cross into Montana Saturday before merging with a central Plains storm system Saturday night. This Alberta clipper/Colorado low hybrid storm will then push up through Minnesota on Sunday bringing strong northerly winds, snow and blowing snow, and bitterly cold temperatures to the Dakotas and parts of southern MB, especially Saturday night into Sunday. The result will be a major winter storm for the northern Plains and much of the southern Prairies along the US border, with blizzard conditions possible in many areas including the Red River valley. A winter storm watch has been issued for the Red River valley in MB with blizzard watches across all of North Dakota and NW Minnesota. For North Dakota information on this storm, consult their winter storm page.

Models continue to show Winnipeg will on the northern edge of the heaviest snow from this system with the bulk of the snow (15-25 cm or more) falling through the Dakotas and northern Minnesota into NW Ontario. Remember though, with storms like this, it's not the total amount of snow that's the problem.. it's the wind in combination with falling snow that creates the problems with blowing and drifting. So it's important not to focus solely on the snow amounts with this system (although that will certainly be a factor), but rather the winds, poor visibilities and extreme windchills.

Winds will be increasing by Saturday evening across southern MB with snow and strong winds continuing Saturday night through Sunday. As a result, there will be extensive blowing and drifting snow Sunday especially through the Red River valley and open areas along the US border with blizzard conditions possible. The Hwy 75 corridor will likely be very bad especially from south of Winnipeg down to Emerson where blizzard conditions are possible Sunday. Travel into the States this weekend is not advised due to this dangerous storm which will likely be shutting down highways across the Dakotas, and possibly parts of southern MB as well. Add to that bone-chilling wind chills of -40 or lower, and you have yourselves a serious winter storm. Get ready folks, this will make for an interesting end to the weekend..

Wednesday, December 10, 2008

Major Arctic blast moving in Sunday....

Another Alberta clipper gave us more snow today with 5-6 cm reported across much of Winnipeg and southern MB. But Mother Nature is saving her worst for the weekend, as a bitterly cold Arctic blast will be moving in by Sunday on the heels of another snow bearing system. This system will be moving into Montana on Saturday then into the Dakotas on Sunday spreading another area of snow across southern MB over the weekend. Another 5-10 cm of fresh snow is expected Saturday into Sunday with this system, on top of the 10 cm that has fallen this week. The problem will be Sunday afternoon and evening behind this sytem as increasing northerly winds gusting to 60 or 70 km/h drives in bitterly cold Arctic air producing poor visilities in blowing and drifting snow. In fact, blizzard conditions are possible over southern MB Sunday afternoon through Sunday night especially over the Red River valley. In addition, temperatures will be plunging into the minus 25 to minus 30 range, with wind chills in the minus 40s. All in all..a nasty end to the weekend with a very cold start to the week ahead.

Monday, December 08, 2008

Cold.. and staying cold..

The weather looks cold for the next couple of weeks at least as a large Arctic airmass spreads over the Prairies. For this week, the cold weather will be briefly moderated somewhat by occasional weak Alberta clipper systems tracking across the southern Prairies from the west. Across southern MB, one of these clipper systems is forecast to track through on Wednesday followed by another one on Friday. Each of these systems will spread cloud and some snow to southern MB bringing about 2-5 cm with each system. Still, these minor amounts in combination with the cold temperatures will make for icy road conditions through the upcoming week. Behind these systems will be a reinforcement of Arctic air into southern MB, especially over the weekend into next week with daily highs in the minus 20s and lows in the minus 30s.

Thursday, December 04, 2008

You think it's cold now.. wait til next week!

Get the cold weather gear and block heater ready.. the coldest weather of the season so far is poised to spread over the Prairies next week with temperatures likely in the minus 20s and minus 30s. We'll get a sneak preview of this cold airmass over the weekend as an Arctic high drops in from the north, giving us highs only in the minus 15 range and lows near minus 25 Saturday night. On Sunday into Sunday night, an Alberta clipper is forecast to spread cloud and snow across southern MB with 2-5 cm possible. In behind this clipper will be a major push of Arctic air as a massive Yukon ridge drives very cold air across the Prairies. This cold air will spread into southern MB on Monday with gusty northerly winds, and temperatures around minus 20, giving windchills of minus 30 to minus 35. Very cold conditions are expected the rest of the week as the Arctic airmass builds in..possibly modified briefly midweek as a weak clipper system scoots by. Look for daily highs next week in the minus 18 to minus 23 range, and lows in the minus 28 to minus 33 range.

Tuesday, December 02, 2008

EC releases winter outlook for 2008/09

EC has issued its winter outlook for the upcoming 3 month period of December through February. The outlook, produced from a consensus of 4 climate models ingesting 3 weeks of current weather conditions and extrapolating into the future, indicates warmer than normal conditions this winter over the East Coast (mainly Newfoundland and Nova Scotia) while colder than normal conditions are forecast from northern Quebec through Hudson Bay and northern MB into NWT and the Yukon. Over southern MB, there are equal chances of a "normal" or below normal winter with a lower probability of a mild winter. Across the rest of the country, model consensus does not point to any specific outcome, with generally equal chances of above, near or below normal conditions (i.e. a non-forecast)

EC's 3 month outlook is available on EC's Weatheroffice website at this site. NOTE: For monthly and seasonal outlooks, I highly recommend you look at the probabilistic outlook map rather than the deterministic outlook map. The deterministic maps do not accurately reflect the true output of the climate models, which is better reflected by the more informative probabilistic maps. The probabilistic maps more accurately indicate where the climate models are showing the best agreement for above or below normal conditions occurring, and where there is the most disagreement. This measure of uncertainty is not indicated on the deterministic maps which make them subject to greater misinterpretation.

Monday, December 01, 2008

Alberta clipper system approaching MB

A strong Alberta clipper system is moving across northern SK today ushering in a gusty southwest flow of very mild Pacific air over southern AB and southern SK. Temperatures have soared into the mid teens over southern AB with several record highs established for December 1st.  This warm airmass will be moving towards southern MB over the next 24 hours, but the bulk of the mild air will be bypassing to the south of Winnipeg into the Dakotas overnight. Even so, gusty south winds tonight of 40-60 km/h will bring rising temperatures overnight to the Red River valley, with temperatures expected to climb towards the freezing mark by daybreak. In fact, there's a chance we may get above zero (+1 to +3C) for a brief period early Tuesday morning as our winds shift into the west and tap some of the retreating mild airmass over southern SK. Regardless, the mild temperatures will be short lived as strong northwest winds develop behind the clipper system Tuesday, and bring increasingly colder air through the day. So watch for temperatures to fall Tuesday, especially in the afternoon and evening as those northwest winds pick up. 

As for precipitation with this system,  it looks like Winnipeg may get a period of snow tonight with a risk of freezing rain or ice pellets overnight as the warm front approaches. The bulk of the snow should remain north of Winnipeg through the Interlake and central MB, but we could see a couple of cm tonight. If any freezing precipitation develops, the best chance will be between 10 pm and 4 am, but amounts should be light. Nonetheless, road conditions could be on the slick side Tuesday morning as this system moves through with some mixed precipitation and near freezing temperatures. Look for windy and colder conditions by Tuesday afternoon with occasional flurries giving a dusting to 2 cm over Winnipeg and the Red River valley.                   


November 2008 Highlights

November 2008 finished milder than normal in Winnipeg and Southern MB, the 4th month in a row with above normal temperatures. Precipitation for the month was also above normal, but that was largely due to a storm system on the 6-7th that brought large amounts of rain, freezing rain, ice pellets and snow to the Red River valley. The last 3 weeks of the month were quiet and inactive, with little in the way of significant precipitation or large temperature swings. As a result, the month seemed to delay winter after a somewhat early start.

Overall, the month finished over a degree above normal with a mean temperature of -4.2C at the airport (-3.2C at my site) vs a long term November average of -5.3C. The month began on a very mild note, with a record high of 18.8C on the 3rd.. the warmest November day in Winnipeg since Nov 5th 1975 when we hit 23.9C (all time November high). The mild start and snowfree ground had golfers enjoying some late season golf through Nov 4th, with no hint of winter like weather. That would change soon enough however as a storm system tracking through from the Dakotas on Nov 6th-7th brought a messy mix of rain, freezing rain, ice pellets and snow to the Red River valley. The storm brought some 40-70 mm of rain and ice pellets to the southern Red River valley bringing high water levels to the Red River on the heels of a wetter than normal fall. By the morning of the 7th, Winnipeg and much of the western Red River valley had been transformed into a winter wonderland, with about 5-8 cm of snow falling in Winnipeg and heavier amounts of 15-25 cm west of the city from Pilot Mound through Portage. Snow has remained on the ground since with a month end snowcover of 5 cm in Winnipeg. Areas further south and east of Winnipeg however saw much less snow with this storm system, and enjoyed snowfree grounds through the end of the month.

After the 7th, the weather turned quiet and uneventful with some minor snowfalls now and then but little in the way of high impact weather. A mid month cold snap brought the month's coldest temperature of -19C on the 21st but that was followed by mild and dry conditions to end the month. The month finished with about 15 cm of snow at my site, slightly less than an average November monthly snowfall of 21 cm.

Overall, an early tease of winter, but a mild and quiet month overall.

Friday, November 28, 2008

Strong clipper to usher in cold blast next week

The weather has been decidedly benign over the Prairies this month, with many places still without a snowcover. In fact, take a drive down Highway 75 from Winnipeg and you'll see little or no snow on the ground by the time you get to Morris.  Likewise much of southern SK and southern AB remain snowfree. The lack of weather systems affecting the Prairies this month has meant little precipitation as well as above normal temperatures, especially over the western Prairies. Things will change next week however as an intensifying Alberta clipper tracks across the Prairies, bringing a band of snow with it, followed by a strong push of cold air behind it. 

Models are indicating this storm system will develop over Northern Alberta next Monday (Dec 1st) moving into the MB Interlake area on Tuesday (Dec 2nd).  The storm system will be preceded by a push of mild Pacific air that will send temperatures well above normal over the southern Prairies Dec 1st-2nd.. especially over snowfree areas. North of the storm track however, a band of snow will be moving across the Prairies pushing into central and southern MB on Tuesday. At this point, models are indicating the bulk of the snow (10-15 cm) will fall mainly north of Winnipeg through the Interlake area and central MB. However, the snow could push further south with a more southern storm track. As the storm moves east into Ontario, cold northwest winds behind it will draw much colder air from the Arctic over southern MB, bringing temperatures into the minus teens for mid to late week, into next weekend.     

Monday, November 24, 2008

NOAA releases winter outlook

NOAA forecasters in the US have released their outlook for the upcoming 2008-09 winter. Their outlook indicates more variability in the weather this winter, with no clear signal for warmer or colder conditions this winter over much of the US. Data suggests only the Mississippi Valley having slightly better odds of a warmer than normal winter. Elsewhere, including the northern Plains, there is not enough predictive correlations to say what kind of winter to expect this year. This is due to the absence of an El Nino or La Nina this year in the Pacific, which historically provide better skill in predicting winter temperature and precipitation patterns, especially in the western US. As a result.. other climatic patterns will influence our winter this year, including the Arctic Oscillation (AO) and North American oscillation (NAO), although these patterns are harder to predict long term, and have less predictive skill to our overall winter than the Pacific ocean patterns. All we can say this year for the upcoming winter in Manitoba is "We'll have to wait and see". Environment Canada will release their 3 month winter outlook for Canada on Dec 1st.

UPDATE: (Nov 27): The NWS office in Grand Forks has released their own local winter outlook for North Dakota based on climatological patterns for the Northern Plains. Their prediction calls for a generally colder than normal winter for the Red River valley, with above average snowfall. Overall, they expect a lot of variability this winter (i.e. roller coaster pattern) with a couple of distinct cold periods.. one from early to mid December, and another from late January to mid February. They also point to a cooler than normal spring.

Dry and pleasant rest of November

The weather has been very quiet here in Southern MB the last couple of weeks, and it appears the quiet weather pattern will stay with us the rest of the month. According to long range models, no major precipitation bearing systems are forecast to affect us through the end of November, which will be a disappointment for those looking for snow, but good news for those not ready to put up with winter's worse just yet. Snowfall has been meager over southern MB this month since our first major snowfall of the season back on Nov 6-7th. Here in Winnipeg, we've had just 2-3 cm of minor snowfalls since the 8 cm in the Nov 6-7th storm. In fact, much of the Red River valley south and east of Winnipeg still has little or no snow on the ground.

Temperatures will also be near to above normal for the rest of the month, with daily highs in the minus 2 to minus 4 mark the rest of the week into the weekend (with above freezing temperatures possible over snowfree areas). So it appears that after a somewhat early start, Old Man winter has taken some time off. Is he resting up for a nasty return visit in December? Or is he just getting old and tired? Time will tell. At this point however, it appears that a major snowfall is not in the cards for southern MB for the foreseeable future.

Saturday, November 22, 2008

Manitoba snowlovers, look away

Our weather has been so boring here lately, I thought I'd post an image showing what heavy snow looks like. This is a photo of a van in Arkona, Ontario buried in over 76 cm of snow that fell during a major snowsquall off Lake Huron Thursday night into Friday morning. (Arkona is located just west of London, Ontario) The snow came down so heavy so fast that numerous motorists were stranded on highways in the area, and emergency officials were forced to use SUVs and snowmobiles to rescue stranded travellers. There were unofficial reports of snow 4-5 FEET deep (120-150 cm) in places. Snowsqualls are a fact of life to the lee of the Great Lakes, but even long time residents in the area say they had never seen so much snow falling in such a short period of time as Thursday night. Given the accumulations, snow was likely falling at 10-15 cm/hr at times during the event. For additional photos on this event, click here and here.

Wednesday, November 19, 2008

Manitoba Lakes Ice Cover

I had a request asking about the status of the freeze up on the Manitoba lakes. The image posted here is a MODIS satellite photo taken Monday afternoon Nov 17th showing the latest ice conditions on our lakes. Dark blue areas are open water, still evident over much of Lake Winnipeg (right) while light blue (turquoise) areas are snow covered and/or ice areas. Grey/white areas are clouds (notice the impressive lake-effect clouds off the lakes) while beige areas are bare ground and green areas are forested. The image shows that much of Lake Winnipegosis is ice covered, except for an open area in the far north, while Lake Manitoba appears to have thin ice forming over much of the basin. I suspect Lake Manitoba will be frozen over by this weekend given the upcoming cold weather.

These high resolution satellite images over Manitoba are available at the MODIS remote sensing website. You can monitor the progress of the lake freeze up with daily updates on this site.

Cold but dry next few days

A large Arctic ridge of high pressure will build over the Prairies today and Thursday bringing cold but dry conditions to southern MB over the next few days. The exception will be over and south of the MB lakes where some lake effect snow is possible today into Thursday. Elsewhere conditions will be dry with generally clear skies tonight through Friday.  Temperatures will be several degrees below normal for mid November with lows in the minus 15 to minus 20 range and highs around minus 10.  A moderating trend is expected over the weekend as a southerly flow develops ahead of another Pacific disturbance tracking across the Prairies. This system may bring some snow over southern MB by the end of the weekend.

Friday, November 14, 2008

Dull November weather continues

The weather sure has been dull here lately, with little in the way of sunshine since winter arrived last week. Other than some sunshine on Remembrance Day, the weather has been generally overcast and dreary since Nov 5th, or 8 of the past 9 days. There is hope that some sunshine will break through the clouds for awhile on Saturday, but another clipper system moving through southern MB Saturday night into Sunday morning will spread more cloud and a chance of snow, especially north and east of Winnipeg. Dry conditions are expected Monday before another threat of flurries by Tuesday. November can be a very cloudy month as colder air moves over still open lake waters, producing frequent clouds even in high pressure ridges. Or in other words.. No sun, no warmth, no wonder.. November!

Friday, November 07, 2008

Winter storm wallops southern MB

After some exceptionally nice weather to start the month, Mother Nature decided it was time to remind southern Manitobans that it's November in the Prairies. The first major winter storm of the season blasted southern MB Thursday and Thursday night with a variety of wintery weather, bringing snow, freezing rain, ice pellets, strong winds, as well as heavy rain to the area. In Winnipeg, the storm began with rain Thursday morning that changed to ice pellets driven by 50-70 km/h winds through the afternoon and evening. Ice pellets accumulated around 2-3 cm by evening along with some freezing rain. Overnight, precipitation changed to snow with 2-4 cm falling on top of the icy mess from the night before. In total, about 25-35 mm of melted precipitation fell over the Winnipeg area, with general snowfall accumulations of 5-8 cm across the city by Friday morning. Heavier amounts of snow were reported further west along the western Red River valley and MB escarpment, with 15-25 cm reported from the Pilot Mound area through Portage La Prairie. The snow and ice left many roads in poor driving conditions across the Red River Valley and SW MB, with travel not advised on several highways into Friday morning.

Further south and east of Winnipeg, precipitation was mostly rain Thursday, with significant amounts of 30-70 mm reported across portions of the southern Red River valley. Overall, an abrupt initiation to winter weather for residents of southern MB!

Wednesday, November 05, 2008

Winter Storm Watch issued for Southern MB for Thursday/Thursday night

EC has issued its first winter storm watch of the season for the Red River valley, Interlake and SW MB areas.  A storm system intensifying over the Dakotas Thursday will spread an area of rain over southern MB through the day Thursday that will change to snow over higher elevations west of the Red River valley. Rain will change through a period of ice pellets and possible freezing rain along the Red River valley Thursday evening before changing to all snow Thursday night. The transition to snow will be slowest southeast of Winnipeg which will keep snow amounts down in those areas. Snowfall totals with this system will be tough to forecast given the uncertainty in timing and location of the rain/IP/snow line, terrain effects, pcpn rate intensity (which can affect rain/snow transition), as well as melting effects of the still warm ground. At this point, preliminary snowfall accumulations by Friday could range from trace-2 cm over SE MB, 5 cm over Red River valley including Winnipeg (perhaps 10 cm north and west of the city into the southern Interlake), and 10-15 cm along the western red River valley/SW MB areas with the highest amounts over higher elevations.  Stay tuned for further updates on this developing situation..

Monday, November 03, 2008

Warmest November day in over 30 years

It was a record breaking mild day across much of southern MB today, as southerly winds pumped in an unseasonably mild airmass from the US.  Temperatures reached 18.8C at Winnipeg airport this afternoon, eclipsing the old record of 18.3C for Nov 3rd, set back in 1903.  The 18.8C reading is also Winnipeg's warmest November temperature since Nov 5 1975, when a high of 23.9C was recorded, Winnipeg's warmest November temperature ever.  The 18.8C reading ranks as Winnipeg's 7th warmest November day since records began in 1872. It was even milder southeast of Winnipeg with 20C readings in places like Sprague and Steinbach. Amazing weather for early November in southern MB! 


Sunday, November 02, 2008

Mild start to November.. snow by Thursday?

It’s been a nice start to November with mild temperatures and dry conditions. The mild weather is expected to continue for the next couple of days before a change to wetter and colder conditions by the end of the week. In fact, the GLB model is indicating the potential for the season’s first significant snowstorm affecting southern MB by Thursday. In the meantime, enjoy these next few days with well above normal temperatures in the low to mid teens and sunny to partly cloudy skies. Things will start to change by midweek as an area of low pressure develops over the Dakotas on Wednesday spreading an area of rain over southern MB.  As the storm system tracks slowly into Minnesota, colder air on the backside of the storm will change the rain to snow over southern MB for Thursday.  At this point, it’s too early to say how much snow we’ll get with this storm, if any, as things are still 5 days away. Some models are indicating the bulk of the precipitation will fall as rain over Winnipeg with some minor wet snow on the back side of the departing storm for Thursday. Other models (like the GLB) are indicating the storm stalling and giving us a significant snowfall Thursday.  At this point, all we can say is the potential is there for our first snowfall by Thursday, but we’ll have to stay tuned to see how the models trend over the next couple of days to have a better idea. My gut feeling is that the GLB is overdoing the snowfall with this system over southern MB for Thursday, but perhaps that’s more wishful thinking than anything scientific (it’s too early for snow for me!) Stay tuned..

Friday, October 31, 2008

Ideal conditions for Halloween

It won't be quite as mild as yesterday's 17-20C weather, but conditions will still be ideal for trick or treaters this evening as a ridge of high pressure moves across southern MB today. Mainly clear skies are expected this evening with light winds and seasonable temperatures. After an afternoon high of +7C today, look for 6 pm temperatures around +4C dropping to +1C by 9 pm.  Best of all, there will be no snow or mud to track through as conditions have been dry for several days now.  Last year, after some rain and wet snow in the afternoon, conditions cleared for the evening with temperatures of +2C at 6 pm falling to -4C by 9 pm.  Two years ago, kids had to track through 10 cm of snow on the ground after a snowstorm on Oct 30th dumped 12 cm of snow in Winnipeg.  

Some Halloween weather highlights for Winnipeg since 1953..

Warmest Halloween…. 1999 - 6 pm temp: 15C
Coldest Halloween….1996 - 6 pm temp: -9C
Wettest Halloween… 2000 - 11.6 mm rain
Whitest Halloween.. 1971 - 18 cm snow on ground  
"Scariest" Halloween.. 1979
Rain changing to wet snow, Temp +1C, winds N 48 km/h 

Thursday, October 30, 2008

Nice finish to October

Some pleasant fall weather will finish up the month of October over southern MB with mainly sunny skies and nice temperatures. In fact, today Winnipeg will get into the mid teens as we get into a brief warm sector that brought some record temperatures in the low 20s across southwest MB and southern SK Wednesday. Cooler air moving in  later this afternoon will prevent Winnipeg from reaching the low 20s as happened further west. Temperatures will be a bit cooler on Friday with highs in the 7-10C range, but conditions should be ideal for trick or treaters Friday evening with mainly clear skies, light SE winds and temperatures around +5C.

Monday, October 27, 2008

Warming trend this week..cooler for Halloween

After a chilly night tonight (-6 to -9C most places) the weather will get a lot nicer this week as warmer air moves in from the west. Sunny skies and light southwest winds will boost temperatures to normal highs of +7C on Tuesday, then look for double digit highs of 10-13c for Wednesday and Thursday with sunshine and breezy conditions. Unfortunately a cold front will drop through southern MB late Thursday ushering a cooler airmass just in time for Halloween Friday. The good news is that it should be clear and dry for Halloween and winds should be dropping off by evening, with temperatures expected to be in the -2 to -5C range for Halloween evening. 

Thursday, October 23, 2008

Taste of winter on tap for Sunday

A strong cold front will push across southern MB late Saturday driving in the coldest airmass of the season so far Saturday night into Sunday across the area. The cold air will be ushered in by strong northwest winds gusting to 70 km/h, with locally higher gusts off the lakes.  Temperatures on Sunday will struggle to reach +3 or 4 degrees, and those gusty northwest winds will make it feel 5 to 10 degrees colder. Most areas in southern MB will likely wake up to see some snowflurries Sunday morning, but localities southeast of Lakes Manitoba and Winnipeg may see heavier bands of lake effect snow Saturday night into Sunday as those cold northwest winds sweep over the open lake waters.  Lake water - 850mb temperature differentials will be approaching 20C by Sunday morning, which is favourable for narrow bands of heavy lake effect snow. Note also that lake levels are running a little higher than normal right now, so northwest gales of 35 to 45 knots over the lakes may produce some shoreline erosion on the eastern shores of Lake Winnipeg and Lake Manitoba. Fortunately it appears this arctic blast will be short lived as lighter winds and moderating temperature are forecast for Monday and Tuesday.  

Monday, October 20, 2008

Nice week ahead.. Major cool down next week?

It should be a fairly nice week ahead across southern MB with generally near normal temperatures much of the week. There will be a band of rain moving across the Red River valley Tuesday night into Wednesday morning (perhaps 5 mm or so), but the rest of the week looks dry and seasonably mild with highs in the 10-13C by Friday or Saturday.  Unfortunately long range models are showing a significant outbreak of cold weather by Sunday the 26th which will likely result in below normal temperatures for the last week of October. In fact, if the models are right, the airmass will be cold enough for the first snowflurries of the year across much of southern MB, with the potential for snowsqualls off the MB lakes.  So be prepared for a chilly Halloween (yet again!), along with the possibility of some of the white stuff around.

Downtown Winnipeg still frost free

Although freezing temperatures have been recorded across most of southern MB by now, the growing season continues in downtown Winnipeg which has still to register a below freezing temperature so far this fall. The lowest temperature so far at the Forks weather station downtown has been 0.3C on Oct 17th.  This morning, while the temperature at Winnipeg airport dropped to a chilly low of -4.8C, the Forks station recorded a low of +1.5C, over 6 degrees warmer than the airport site.  This difference is due to a phenomenon known as the "urban heat island" effect, which basically keeps temperatures (especially nighttime temperatures) warmer in a downtown core compared to nearby rural areas which can lose heat to the environment more effectively. This prolongs the average growing season downtown by 2-4 weeks compared to the airport site. 


Sunday, October 12, 2008

Storm system brings rain and snow to southern Prairies

The storm system affecting the eastern Prairies continues to spread rain into southern MB this morning, which turns to snow across the border into Saskatchewan. Snow will continue to fall across much of southeast and southcentral SK today into tonight with snowfall totals of 10-20 cm possible by Monday, and locally up to 25 cm over higher elevations south of Moose Jaw.

For southern MB, the story will be rain today which should continue most of the day. Rainfall amounts should be about 15-25 mm over SE Manitoba including Winnipeg, with 25-35 mm possible over parts of SW Manitoba.

Thursday, October 09, 2008

Thanksgiving weekend outlook

Cool and unsettled conditions will be the main story for the upcoming Thanksgiving weekend over southern MB. A sharp frontal boundary is forecast to develop across the Dakotas on Saturday before a storm system tracks across southern MB on Sunday, followed by windy and cooler conditions on Thanksgiving Monday. The details..

Saturday should be cloudy and cool across southern MB as the frontal boundary begins to set up across the eastern Dakotas into northern Minnesota. This boundary will be separating warmer and drier conditions to the east from cool and wet conditions to the west. An area of rain will develop along this frontal boundary over the Northern Plains and spread into southern MB Saturday afternoon and evening. Rain may become heavy at times Saturday night into Sunday morning, with thunderstorms possible, as a low pressure system develops over the western Dakotas and tries to spread warmer air into southern MB. Rain from this system will continue to spread to the north and west of Winnipeg on Sunday, so there may be a break from precipitation Sunday afternoon over the Red River valley and SE Manitoba. Sunday night, a cold front from the low will sweep across Southern MB, bringing windy and cooler conditions on Monday, with clouds and a chance of showers.

My holiday weekend forecast for Winnipeg. Note that the timing of the precipitation will be subject to change based on how these systems develop over the next day or two. At this time, this is what the models are saying.. (updated Saturday morning)

Saturday..Cloudy and cool. Chance of showers this afternoon. High 9.
Saturday night..Periods of rain developing. Low 7.
Sunday..Rain heavy at times tapering off in the afternoon. Chance of a thunderstorm. Total rainfall amounts 15-25 mm. High 14.
Sunday night..Chance of showers. Low 5.
Monday..Mostly cloudy, breezy, cooler. Chance of a shower. High 8.

Saturday, October 04, 2008

Nice weekend.. showers moving in Monday

A beautiful weekend out there as the remnants of the massive upper ridge that gave record breaking warm temperatures over Alberta and western SK moves over Manitoba. We won't get quite as warm as the 25-29C readings enjoyed to our west this past week, however we will get into the mid to upper teens with plenty of sunshine both today and Sunday along with brisk south to southeast winds. Look for clouds to move in by Monday with rain developing as a frontal trough moves in from the west. Right now, rain amounts look to be in the 5-15 mm range for Winnipeg and the Red River valley, but local amounts of up to 25 mm are being hinted at by some models.

Wednesday, October 01, 2008

September a little warmer, a little wetter

September 2008 finished a little warmer and wetter than average, coming off a warmer and wetter than normal August. The mean monthly temperature at Winnipeg airport was 13.0C, or 0.7C above the 30 year average of 12.3C for September. (Sept 2008 averaged 13.3C at my site, 14.2C at the Forks) Temperatures averaged cooler than normal for the first week, then were generally near or above normal for the rest of the month. The highest temperature was a 29.2C reading on the 18th (29.6C at my site) while the lowest was -0.5C on the 27th, marking the official end of the growing season at the airport site. Elsewhere across the city however, September remained frost free with a monthly low of +1.4C at my site, and +3.4C at the Forks downtown. As a result, most flowers and gardens were still in bloom by month's end.

Rainfall for the month was above average at 77 mm (82 mm at my site - average September rainfall 52 mm) but that was mainly due to two main rain events on the 1st, and the 22-24th when thunderstorms brought locally severe thunderstorms and heavy rain. The rest of the month was fairly tranquil with minimal precipitation and frequent dry days, making for pleasant late summer weather… a welcome extension to a summer that started off cool and wet.

All in all, a pleasant end to the summer of 2008.

Monday, September 29, 2008

Getting better and better this week

A massive upper ridge of high pressure will be building over western Canada this week, bringing some superb late summerlike weather over AB and Saskatchewan this week. Daily highs will be in the 25-29C range all week in southern AB and southwest SK with sunny clear skies through Friday. Here in southern MB, we will be on the eastern flank of the upper ridge much of the week, which will keep us cooler than the western Prairies. Still, after some cloudy and cool conditions to start the week, the rest of the week should be getting progressively better with daily highs approaching the 20 degree mark by mid to late week. That should lead us into a nice warm weekend with highs over 20 degrees as the upper ridge moves east over southern MB. All in all, it's looking like a nice start to October!     

Friday, September 26, 2008

Nice stretch of weather coming up..

Looks like some pleasant fall weather coming up over the next few days into next week as a large upper ridge begins to build over western Canada early next week. This upper ridge will bring sunny warm and dry conditions to Alberta and Saskatchewan much of next week, with some of that weather moving into southern MB by Tuesday.

In the meantime, skies have cleared across southern MB today behind a weak cold front that moved across the region this morning. High pressure will build into southern MB tonight giving clear skies and diminishing winds.. with some patchy frost possible by early Saturday.  This high pressure system will bring ideal fall weather on Saturday with plenty of sunshine and light winds, making those afternoon highs of 17 degrees feel even warmer.  On Sunday a low pressure system moving through the Interlake regions will spread an area of cloud and scattered showers across central and southern MB. This system is now forecast to move further north than earlier expected, thus the threat of rain will be lower for Winnipeg and areas south. As a result, we may get by with a rainfree weekend here.  

Once this system passes to our east, clearing skies and seasonable temperatures are expected over southern MB for Monday and Tuesday with more sunshine and even warmer temperatures likely by Wednesday as the western ridge builds east.  Some models are indicating that this ridge will collapse over the eastern Prairies by late next week allowing cooler air to return over us again, while the Cdn GLB model keeps us dry and warm right through next week.  It's still a long way off to say one way or another.. but in the meantime, enjoy the fine stretch of weather coming up!        

Tuesday, September 23, 2008

Strong thunderstorms bring heavy rain, high winds

The first official day of fall was marked by strong thunderstorms last night that brought a swath of heavy rain over the Red River valley, as well as some severe wind gusts along the US border. Thunderstorms developed over northern North Dakota late Monday, and pushed into southern MB during the evening. As the storms crossed the border into Manitoba, they produced torrential rain and wind gusts to 106 km/h (57 knots) at Emerson at 10:43 pm, and an unverified gust of 165 km/h (89 knots) at Gretna at 10:42 pm. Although possible, the Gretna gust seems suspiciously high since there would have been damage reported with such wind gusts, and no reports of damage have been received so far. The storms were accompanied by 29 mm of rain within one hour at Gretna, and 34 mm of rain within one hour at Emerson between 10 and 11 pm.

The storms continued to move to the northeast through the night bringing a swath of heavy rain mainly from the Gretna/Emerson areas through Letellier/Dominion City to St Pierre up to the Landmark area just east of Winnipeg. Rainfall in this swath totalled 50-90 mm from overnight thunderstorms. The heavy rain area just clipped the east side of Winnipeg with Deacons Corners (Hwy 1/Perimeter) reporting 46 mm of rain since midnight, while the west end of the city only had 15-20 mm including Winnipeg airport and my site in Charleswood.

Some rainfall amounts recorded since late yesterday include.

Dominion City… 91 mm (spotter report)
Landmark………78 mm (including 44 mm 9 pm - midnight)
St Pierre………..72 mm (MB Ag-wx)
Emerson………. 65 mm (EC)
Morris…………. 62 mm (MB Ag-wx)
Winkler………… 58 mm (MB Ag-Wx)
Dugald………….53 mm (MB Ag-Wx)
Steinbach………46 mm (MB Ag-Wx)
Gretna…………..46 mm (EC)
Wpg - Deacons Corners…46 mm (CWB)

Winnipeg Forks…. 22 mm (EC)
Winnipeg Arpt….. 17 mm (EC)

Sunday, September 21, 2008

Nice end to summer.. unsettled start to fall

It was a beautiful end to summer over southern MB with sunny skies, balmy southeast breezes and temperatures in the 25C range. Fall officially arrives Monday morning at 10:44 am, and will be greeted with some unsettled weather in the form of showers and possible thunderstorms. The unsettled weather will come in two waves. The first wave of precipitation is expected overnight as a band of showers and scattered thunderstorms over North Dakota moves northward into the Red River valley. These showers may bring 5 to 15 mm of rain to Winnipeg overnight, although heavier amounts of 25-35 mm are possible in thunderstorm activity over portions of southern MB by early Monday morning. There should be a break in the shower activity through midday Monday which will allow temperatures to warm into the 20s along with dewpoints in the midteens. This will set the stage for another round of showers and thunderstorms to develop by late afternoon over southern MB ahead of a cold front. This line of activity may be accompanied by severe thunderstorms late Monday into Monday evening with heavy downpours (giving local rainfall amounts of 30-50 mm), strong winds, and possibly large hail. There may even be the threat of isolated tornadoes with some supercell storms early in the evening. Stay tuned as Mother Nature may be ushering in fall on a stormy note.

Wednesday, September 17, 2008

Late summer weather before fall arrives Monday

Some nice weather is on tap for Southern MB over the next couple of days as Mother Nature gives us some late summer weather before the official start of fall on Monday. Thursday will see brisk southerly winds of 40 to 60 km/h developing in the Red River valley as a warm front moves through southern MB. Afternoon temperatures will climb into the 24-27C range along with plenty of sunshine. Friday will see a weak cool front push through from the Interlake, but temperatures should remain above normal Friday with highs of 25C or so before cooling off in the afternoon or evening as northerly winds develop. Saturday will likely see cooler temperatures as we get northeast outflow winds from a cool high pressure area over northern MB. Current advertised highs of 25C are likely over-optimistic for Saturday, with highs of 17-20c more likely in the cooler airmass. There could also be considerable cloudiness around along with areas of dense fog as that frontal boundary remains stalled over southern MB separating warm air to our south from cooler air to the north. (in fact, Saturday's weather may be much like today's.. overcast and cool) By Sunday we should be getting back into south or southeast winds which would boost temperatures back into the low to mid 20s (current advertised high of 27C still likely about 5c too high for Winnipeg and areas to the north and east) So although the bulk of the weekend is expected to remain dry, I don't think it's going to be as warm or as sunny as current forecasts indicate.

Fall officially arrives at 10:44 am Monday morning but current models are suggesting we'll be staying with above normal temperatures in the low to mid 20s through Tuesday before more fall-like temperatures return by mid to late week.

Monday, September 15, 2008

Ike damage

Hurricane Ike has brought incredible devastation on the Bolivar Peninsula just east of Galveston along the Gulf Of Mexico. This area was the hardest hit being on the east side of Ike's eyewall. Communities of Crystal Beach and Gilchrist have been wiped off the map by Ike's winds and storm surge which likely topped 15 feet over this unprotected peninsula.The image on the left shows a single home standing in what used to be the beachside town of Gilchrist. Satellite images show the extensive damage brought to the Texas Gulf coast, including the destruction of Crystal Beach.

Sunday, September 07, 2008

Lake effect season is here

This morning is providing a good example of a common phenomenon in southern MB in the fall - lake effect precipitation. Lake effect precipitation develops when you have cool air aloft moving over the relatively warm lake waters, creating narrow bands of instability precipitation to the lee of the lakes. You need at least a 13C difference between the lake water and the temperature at 850 mb, and winds need to be well aligned in the lowest 10000 feet (i.e. little directional shear) to form these narrow bands. This morning we have 850 temperatures of +2C over 18C lake waters, along with low level winds aligned in a 330-340 degree orientation giving lake precipitation to the southeast of Lakes Manitoba and Winnipeg. Typically these lake effect bands form in the cool air behind a cyclonic storm system and will dissipate as subsidence moves in with an approaching ridge of high pressure.

Early in the season, these precipitation bands are in the form of rainshowers. As we get further into the fall with colder temperatures aloft (i.e. 850 temps of -5C or colder), these lake effect bands will produce narrow swaths of snow to the lee of the lakes.. sometimes quite heavy. See an example from October 11, 2006 for an early season lake effect snow event over southern MB.. notice that the lake effect bands from that case are oriented virtually identical to those this morning (except it's rain today, not snow!) Lake effect bands off Lake Manitoba commonly set up between Portage and Elie, but can come into Winnipeg if the low level flow is in the right direction, from around 300 degrees, as seen in this example from last September.

Thursday, September 04, 2008

Some rain on the way

A weak low pressure system over North Dakota will be tracking slowly east over the next 24 hours, bringing an area of rain to southern MB. The leading edge of the rain shield is just spreading up to the MB border from the south as of midday, and should continue edging north this afternoon likely reaching Winnipeg by mid to late afternoon. Rain amounts are expected to be in the 5 to 15 mm range, most of it falling south of Winnipeg closer to the international border. Here in Winnipeg, look for about 5 mm from late afternoon through tonight. Cool unsettled weather is expected behind this system for Friday through the weekend. 

Thursday, August 28, 2008

Summer's last hurrah?

It looks like the fine summer-like weather we've enjoyed through much of August will close out the month this weekend with another round of summer-like warmth, especially over SE MB. But as if on queue, a sharp cold front will move across southern MB late Sunday or Monday bringing in much cooler and wetter weather just as the calendar flips to September. The details..

An upper ridge will build over southern MB on Saturday giving us a fine start to the Labour day weekend. Saturday will see plenty of sunshine across southern MB with temperatures in the mid to upper 20s along with increasing southerly winds.  This upper ridge is forecast to build over Ontario over the long weekend, while cooler unsettled weather moves in over the western Prairies. The dividing line between these two airmasses will set up right through southern MB on Sunday along a cold front that is expected to drop southward across the Interlake and stall from southwest MB through Winnipeg into the Pinawa area.  There will be a dramatic temperature difference across this front with summerlike temperatures of 27-30C to the south and east, and more fall-like temperatures of 20C to the north and west along with clouds and a chance of showers. Current forecasts for Winnipeg call for a high of 30C on Sunday, but I'm a little skeptical we'll get that high with that Interlake front so close to us (major bust potential Sunday because of this front). I think areas south and east of Winnipeg will have a better chance of seeing 30 degree temperatures on Sunday (including the Whiteshell, Lake of the Woods and the southern Red River valley), while places like Grand Beach through Gimli to the Riding Mtns will be considerably cooler on Sunday (highs only near 20C).

For holiday Monday, models indicate this cold front will sweep through southern MB, bringing in cooler weather for all areas but the extreme southeast along with a good chance of rain, possibly heavy in parts of southwest MB into the Interlake.  All in all, looks like the best bet for a warm dry long weekend will be toward the SE corner of the province (e.g. Whiteshell, Lake of the Woods and southern Red River valley), while cooler and wetter weather moves in by Sunday to areas further north and west (especially SW MB through the Interlake). As always.. stay tuned…the forecast for this long weekend will be a tricky one.   

Tuesday, August 26, 2008

Windy and warm today.. risk of thunderstorms tonight

Windy and warm conditions are on tap today as a gusty southerly flow develops ahead of a sharp cold front pushing through Saskatchewan. Southerly winds will gust up to 70 km/h this afternoon up the Red River valley, as temperatures climb into the upper 20s. Scattered showers and thunderstorms will develop ahead of the approaching cold front this evening and tonight, with a slight risk of severe thunderstorms over portions of western MB this evening with strong wind gusts as the main threat. The storms may produce some heavy rain, but any storms that develop will be moving rapidly which will diminish the heavy rain threat.. good news for areas hard hit by last week's locally torrential rains.

Thursday, August 21, 2008

Showers/thunderstorms on tap tonight into Friday

A cold front approaching from Saskatchewan will trigger a band of showers and thunderstorms over southern MB beginning this afternoon and continuing through tonight into Friday. The heaviest activity in terms of thunderstorms is expected to develop over southwest MB later today then move northeast through the Interlake tonight. Locally severe thunderstorms are possible along this swath with the potential for large hail and damaging winds along with local rainfall amounts of 20-40 mm. Showers and scattered thunderstorms will be spreading across the remainder of southern MB tonight into Friday with rainfall amounts of 10-20 mm possible. Noticeably cooler weather will move in behind this cold front for Friday and Saturday with high temperatures some 10-15 degrees cooler than the 30 degree weather of the past week. Warmer weather is set to return to southern MB by Monday.

Monday, August 18, 2008

Winnipeg finally hits 30 degree mark - latest date on record

The temperature at Winnipeg airport hit 30.2C on Saturday August 16th, the first official 30 degree day of the summer at Winnipeg's official weather reporting site.  This marks the latest date that Winnipeg has reached the 30 degree mark since records began in the city in 1872.  The previous latest date for hitting 30C was July 24th back in 1927 and in 1882.  Thus, this year was over 3 weeks later than the previous latest date.   The average date for hitting 30C is around June 4th based on Winnipeg climate data since 1872.

Note that Winnipeg airport observations began in 1938.  Before that, weather readings were taken at St John's College in St Boniface from 1872-1938. 



2008...AUG 16…. 30.2C…..138   
1882…JUL  24…. 30.0C…..115   
1927…JUL 24….. 32.2C…..115
1920…JUL 19….. 31.7C…..110
1967….JUL 15…. 30.0C…..106


Thursday, August 14, 2008

Another summery weekend on tap!

If you enjoyed last weekend's summery weather, you're going to like this weekend as well as Mother Nature serves up another stretch of sunny hot weather over southern MB. An area of unsettled weather over SW Manitoba today will give way to sunshine Friday that will last through the weekend into early next week as an upper ridge of high pressure builds over the Prairies. Daily highs will be near 30 degrees each day giving the Winnipeg airport site its best chance yet to finally hit the 30 degree mark this summer (I'm betting we'll hit 30 this weekend) Summer of 2008 ain't over yet!

Monday, August 11, 2008

Heavy rain possible over portions of Red River valley tonight

A slow moving trough of low pressure over SW Manitoba will feed a southerly flow of moist unsettled air over southern MB today and tonight resulting in widespread showers and embedded thunderstorms.  The slow moving and persistent shower activity will result in locally heavy rain as showers and thunderstorms advect over the same area (an effect known as "training") . Showers and thunderstorms will be most frequent over eastern ND today where flood watches are in effect due to the potential for 50 to 75 mm of rain in some areas. This area of heavy rain is forecast to spread northward into the Red River valley this evening and tonight, with 25 mm or more possible in areas mainly south and west of Winnipeg (although Winnipeg may also see significant amounts if the rain area expands further north).  Note that locally heavy downpours this morning produced 32 mm of rain in Snowflake, 66 mm in Manitou, and 62 mm near Miami so a repeat performance is possible again tonight in some areas of the Red River valley. 

Wednesday, August 06, 2008

Finally! - Extended stretch of sunny warm weather ahead

It's been a rarity this summer, but it looks like southern MB will have an extended period of sunny warm weather ahead this week.. possibly lasting right through the upcoming weekend.  A large upper ridge of high pressure is forecast to build over the Prairies this week which will help to maintain sunny and stable conditions from the Rockies into northwest Ontario.. a nice change from the persistent unstable airmass that has brought almost daily shower and thunderstorm activity across the Prairies this summer. Temperatures in southern MB will be pleasantly warm this week.. in the 25-27c range climbing into the upper 20s to low 30s over the weekend. The GFS is even indicating a high of 33C for Winnipeg by Sunday. Perhaps YWG airport will finally hit that elusive 30C mark yet this summer!   Whatever the case.. it finally looks like some nice beach weather ahead this week and weekend over southern MB.     

Monday, August 04, 2008

Sun disappears for long weekend

Well.. bad timing, but today is the third day in a row of cloudy skies and local shower activity over the Red River valley and SE MB.. all due to convection over the northern Plains that has spilled over into southern MB. Rainfall has been minimal in the Winnipeg area, but persistent cloud and temperatures in the low 20s has made this last long weekend of summer not very summerlike. It looks like summer heat just can't get established this year over the southern Prairies as the jet stream remains stalled over the northern Plains.. with time running out for it to shift any further north.

Monday, July 28, 2008

Severe thunderstorms likely today

A cold front pushing across southern MB today will bring an increasing threat of thunderstorms today.. with the possibility of severe thunderstorms bringing large hail and possible tornadoes to portions of southern MB this afternoon into this evening. This same system produced numerous reports of severe weather across southern SK Sunday with at least 4 tornado reports. Residents of southern MB should stay tuned to updated forecasts and possible watches and warnings today on this potential severe weather outbreak.

Thursday, July 17, 2008

Weekend washout?

Forecasts for the weekend appear rather pessimistic for Winnipeg and southern Manitoba with showers forecast for both Saturday and Sunday and high temperatures only near 20C. But will it be that bad? Other computer models are more optimistic for the weekend showing more typical summerlike weather with only scattered showers and possible thunderstorms over the weekend, but dry most of the time, along with some sun and increasing humidity. The Canadian GLB seems to be the most aggressive with an impulse moving through the northern plains, generating a wide swath of heavy convective precipitation over southern MB. Who's right? We'll have to see what the trends are over the next run or two, but at this point, I'm thinking this weekend will not be a total washout as the GLB suggests, with partly sunny skies, more humid conditions giving scattered showers and thunderstorms at times, and high temperatures in the 22-25C range. Rest assured, this will not be a repeat of last Saturday's wet and wild weather!

Sunday, July 13, 2008

Unseasonably strong system whips Southern MB

An intense storm system moved northeast of Berens River Saturday bringing a large swath of rain and strong winds over southern and central MB. The storm system.. which deepened to 984 mb.. was more typical of a fall-type storm system that commonly brings strong winds and rain to Manitoba. But such a system is unusual for the middle of July, and prompted the issuance of a rare July gale warning over the MB lakes where wind gusts over 45 kt were recorded on the eastern shores of Lake Winnipeg and Lake Manitoba. The strong winds extended over all areas of southern MB resulting in numerous broken tree branches across the area. Rainfall with this system ranged from 10-20 mm over Winnipeg and the southern Interlake to 50-75 mm over the northern lakes in places like Grand Rapids and Norway House.

Some peak wind gusts recorded yesterday included..

Oak Point Marine..... 94 km/h (east shore of Lake Manitoba)
Victoria Beach....... 91 km/h (east shore of Lake Winnipeg)
Brandon.............. 78 km/h
Dauphin.............. 78 km/h
Winnipeg............. 74 km/h
Gimli................ 69 km/h

Much better weather is in store today with sunny skies and lighter winds. After yesterday, we deserve it.

Friday, July 11, 2008

July 11 1936 - Winnipeg's hottest day

On this date in 1936, Winnipeg registered its hottest day ever when the thermometer hit an unprecedented high of 42.2C (108F). In 136 years of weather records in the city (since 1872), Winnipeg has never recorded such an extreme temperature. The milestone was reached during a historic and unparalleled heat wave that gripped much of central and eastern North America that July. Many high temperature records in the US and Canada still stand from this historic heat wave.

Front page of the Winnipeg Evening Tribune, Monday July 13 1936
after Winnipeg's hottest and deadliest weekend on record
In Winnipeg, the heat wave started on July 5th and persisted for 2 weeks before easing on the 18th. From July 5-17, Winnipeg recorded 13 consecutive days above 30C, the longest such streak in Winnipeg history. During that stretch, 11 daily record highs were set or equalled which remain unbroken to this day.. an unparalleled feat in Winnipeg climate history. 9 of those days were 35C or more with 2 days hitting over 40C, including Winnipeg's all time mark of 42.2C on the 11th. The average daily high temperature during this period was an incredible 36.4C. Nighttime offered little relief from the heat with overnight lows rarely dropping below the 20C mark. In particular, the night of July 11-12th must have been unbearable for Winnipeg residents. After hitting an all time high of 42.2C on the 11th, the thermometer dropped to a "low" of only 28.3C the following morning, Winnipeg's warmest ever nighttime low and the only time on record that the daily minimum temperature has remained above 25C in Winnipeg. In fact, on that night the temperature was at or above 30C most of the night. Imagine living in those conditions without air conditioning! The heat was so unbearable, many residents were forced to sleep outside to escape the heat of non-airconditioned buildings. For many residents, the heat was too much with at least 70 heat related deaths recorded in southern MB, including at least 31 in Winnipeg alone along with another 40 hospitalized for heat prostration (as reported by Winnipeg Tribune). That death toll makes the 1936 heat wave the deadliest weather related event in Winnipeg history.

Reconstruction of hourly temperatures in Winnipeg on July 11 1936
Hourly temperatures are estimated based on 3 known values that day
Even hotter temperatures occurred elsewhere in Southern Manitoba during the 1936 heat wave. Emerson MB near the US border recorded 13 consecutive days over 35C between July 5th and 17th, with an average high of an incredible 39.9C over the 13 day period. The heat wave included a phenomenal 7 days of 40C or more including a maximum of 44.4C on the 12th, Manitoba's hottest temperature on record. In fact, it was Canada's hottest ever temperature until Midale and Yellow Grass in southeast Saskatchewan hit 45.0C the following summer. During July 1936, Emerson registered 27 days of 30C or more, with an average high of 34.6C for the month, almost Arizona like. Between the 5th and the 13th, the town registered a remarkable 9 consecutive days of 100F or higher (37.8C) 

Daily temperatures at Winnipeg and Emerson
during the July 1936 heat wave

Further south in North Dakota, the town of Steele (between Bismarck and Jamestown) hit an unfathomable 49.4C (121F) on July 6th 1936 - the hottest temperature in North Dakota history. Such a temperature rivals the type of extreme heat found in the US desert southwest, and is almost as hot as Phoenix AZ's all time high of 50C/122F!  The weather observer in Steele (Mrs R.G. Armstrong) noted on her weather summary that "flowers on trees and shrubbery were cooked" due to the intense heat that day. July 6th 1936 saw all time highs established in Bismarck (45.6C/114F), Fargo (45.6C/114F) and Jamestown (47.8C/118F), records that still stand to this day. (read more about North Dakota heat here)

High temperatures (F) - North Dakota - July 6 1936
The hottest day in North Dakota history set all time highs
in Bismarck and Fargo (114F), as well as the state (Steele, 121F)
Official weather obs for Moorhead MN (near Fargo) for July 6 1936
The form notes an all time record high of 114F was set at 3:15 pm that afternoon
By all accounts, the 1936 heat wave was a historic and unparalleled heat wave that has yet to be matched in weather record keeping. 6 years of drought had left the Prairies bone dry and crops withered, allowing maximum heating of the surface during the hot summer months. For this particular heat wave, a huge upper ridge must have developed over central North America, allowing extreme temperatures to reach well north into southern Canada. The upper pattern would have been stationary for at least 2 weeks, allowing the unrelenting heat to persist for days on end, intensified by the early July sun. Whatever the cause, the conditions that led to the 1936 heat wave have never come together again to the extent they did 72 years ago this week. So as you complain about this year's cool summer weather, try to think what residents of Manitoba had to endure during the granddaddy of all heat waves - July 1936.

It was so hot during the 1936 heat wave, may residents were forced
to sleep outside. This scene was from St Paul Minnesota

More severe storms this afternoon.. Fall-like Saturday

Southern MB remains under a severe thunderstorm watch this afternoon as a low pressure system over eastern North Dakota draws a warm and humid airmass northward. Morning thunderstorm activity has pushed into the northern Interlake this afternoon, while the south gets a temporary reprieve from the severe weather. However, as the North Dakota low moves into southern MB later today, a flow of warm and humid air will be drawn over southeast MB while a cold front pushes in from the west. This will set the stage for additional severe thunderstorms to develop, especially over the Red River valley and southeast MB. Strong winds and large hail will be the main threat, however favourable wind shear profiles over southeast MB may give the threat of tornadoes with any supercell thunderstorms that develop.

As this low pressure system moves north into the Interlake tonight, it will deepen into an almost fall-like storm by Saturday morning with strong west to northwest winds developing on the backside of the low. Gale warnings have been issued for the MB lakes with west to northwest gales of 40 knots forecast for Saturday. This will likely generate large waves over the south basins of Lakes Winnipeg and Manitoba with possible shoreline erosion problems on eastern and southern shores.  Temperatures will also be unseasonably cool Saturday with highs only in the mid teens along with occasional rain making it feel more like September than mid July.  Not a good day for Grand Beach unless you like windsurfing!    

Wednesday, July 09, 2008

Severe storms Thursday evening?

Looks like another setup for possible severe thunderstorms to develop across Southern MB late Thursday into Thursday evening. A low pressure system and trough will be moving across southern SK Thursday moving to the SK/MB border by Thursday evening.  A warm front extending east of this system will lie across the MB/ND border by evening which will be the focus for thunderstorm development.  South of the warm front, warm and humid air will be advecting north from the Dakotas and will nose into Southern MB especially south and west of Winnipeg.  Favourable low level wind shear and an increasing jet stream aloft will set the stage for supercell storms to develop across the Dakotas and southwest MB, with the potential for large hail and possible tornadoes. The limiting factor in this setup will be how much moisture can de drawn into this system in a short period of time, since dewpoints are quite low across the northern Plains today. As a result, the severe weather threat may be late Thursday before sufficient moisture can be drawn into this system. Stay tuned..    

Thursday, July 03, 2008

Thunderstorms possible Saturday evening

Hot weather will be returning to southern MB over the next couple of days with highs approaching 30 degrees Friday, likely reaching the low 30s on Saturday. Saturday will also see increasing humidity levels as southerly winds tap more humid air to our south and advect it north. This will set the stage for possible strong to severe thunderstorms to develop by Saturday evening over the Red River valley as a weak cold front approaches from the west. Behind the cold front, more comfortable conditions will return for Sunday with seasonably warm and less humid conditions.  

Tuesday, July 01, 2008

Some smoke and fireworks for Canada Day

Mother Nature has served up some of her own Canada Day fireworks today with some severe thunderstorms firing up over southeast MB ahead of a cold front pushing through from the north. The front moved through Winnipeg just before 5 pm, shifting winds into the north and dropping temperatures and humidity levels noticeably bringing relief from the hot and humid conditions this afternoon. The brisk northerly winds however are ushering in a large area of smoke aloft from northern SK forest fires into southern MB. Residents of southern MB will notice a hazy look to the sky this evening along with locally reduced visibilities, a brilliant red sunset, and a distinct smell of smoke.

Sunday, June 29, 2008

Heat building over Prairies

A large upper ridge of high pressure over western Canada is bringing the season's first taste of hot weather over the western Prairies today which will be spreading east into southern MB by Monday. High temperatures in southern Alberta will soar into the mid 30s today, while parts of the Okanagan in BC will hit the 40 degree mark. Here in Winnipeg, we have yet to hit 30 degrees this year.. but it looks like we will finally hit the mark on Monday with a forecast high of 31c. The 30 degree weather will be short lived however as cooler air moves in on the July 1st holiday and persists for the rest of the week. Temperatures on the July 1st holiday will still be warm.. in the upper 20s.. but they will be cooling off by evening as northerly winds bring in cooler air from the north. It should be dry however with no precipitation expected. Conditions for the remainder of the week look pleasant with generally sunny skies and temperatures in the mid 20s. Long range models are hinting at a return of hotter weather over southern MB next weekend into next week.

Thursday, June 26, 2008

Showers and thunderstorms possible tonight into Friday

A developing low pressure system over southern Saskatchewan will tap an increasingly moist and unstable airmass over the Dakotas to trigger scattered thunderstorms over North Dakota today. Some of the storms over the Dakotas are expected to become severe later today into this evening with much of the northern Plains in a slight to moderate risk of severe thunderstorms. As the low pressure system advances east, showers and thunderstorms will spread over southern MB tonight.. with the potential for locally heavy rain (20-30 mm).. intense lightning.. and hail, especially over southwestern MB. This activity will push through Winnipeg and the Red River Valley Friday with drier conditions moving in by evening as a dry slot pushes in. Cooler unsettled weather will return for Saturday in behind the low with brisk northwest winds and a few showers over southern MB.  Highs will likely struggle to reach 20 degrees Saturday. Sunny and warmer weather is expected for Sunday Monday and Tuesday with highs likely approaching the 30 degree mark by the July 1st holiday.

Saturday, June 21, 2008

Storms develop over east Winnipeg

Thunderstorms have developed along a lake breeze convergence zone between Lake Winnipeg and Lake Manitoba, setting up right through the middle of Winnipeg. (see radar image) The N-S convection axis cuts right through the middle of the city, with storms pretty much confined to the east end, nothing but blue skies in the west. Localized downpours, and small hail have been reported with the storms. Storms are moving to the south-southeast at about 40 km/h.

Wednesday, June 18, 2008

Severe tstms over SW Manitoba

A line of severe thunderstorms has developed over SW Manitoba this afternoon, bringing hail as large as ping pong balls between Melita and Virden and loonie size hail just south of Melita. This line is moving east at 40 km/h and has the potential to produce additional large hail and damaging wind gusts of 90 to 100 km/h.  This line will continue moving east through the afternoon, possibly reaching the Red River valley this evening. We'll have to see if these storms remain severe by that time.

Monday, June 16, 2008

Red River update

The Hydrologic Forecast Centre of Manitoba Water Stewardship advises that the Red River continues to rise due to heavy rainfall June 6-12, 2008. The crest is presently at Grand Forks, North Dakota.

At Emerson the river has risen 13 feet since early June and is expected to rise another 6 feet before it crests on June 22. At Ste. Agathe the river has risen 8.7 feet since early June and is expected to rise another 4.9 feet before it crests on June 24. In downtown Winnipeg the river level this morning stood at 8.1 feet above datum, a rise of 1.7 feet since early June. It is expected to crest between 9 and 10 feet above datum June 24-26.

Public Works and Government Services Canada (PWGSC) will continue to operate St. Andrews Dam at Lockport to maintain levels below 8.5 feet (Forks walkway level) in Winnipeg for as long as possible. However a minor inundation of the walkways is expected for a period of one week beginning this weekend.

Levels just upstream of St. Andrews dam have been declining as usual due to opening of the dam. PWGSC will issue information regarding operation of the locks for boat traffic. River levels from Selkirk to Breezy Point will rise 4 to 6 feet above normal summer levels which will not present any significant difficulties.

While the Red River will be well above average for the next few weeks it will remain well within its banks unless additional widespread heavy rain develops during the next few weeks. Boaters and canoeists are advised that the river current will be stronger than usual for the next few weeks, and therefore caution is advised.

Finally! - sunny warm stretch ahead

Well, it's been a long time in coming.. but it finally looks like southern MB will see an extended spell of sunny warm weather this week.  An upper ridge will be building over the Prairies this week, giving warmer temperatures in the mid 20s and more importantly, a lack of precipitation bearing weather systems.  This will finally give southern MB a break from a week of heavy rainfall, and a much needed spell of warm weather. Southern MB has basically been below normal temperature wise for the past 8 weeks.  This upcoming stretch of warmer weather, along with adequate soil moisture in all regions, will go a long way in accelerating crop development which has been slow due to the cool spring.