Wednesday, December 19, 2007
Wednesday, December 12, 2007
An Alberta clipper system will be tracking across southern MB overnight into Thursday morning, bringing some snow and gusty winds behind it. The combination of fresh snow and increasing north winds will create reduced visibilities in blowing snow mainly over the Red River valley on Thursday, especially in open areas outside of Winnipeg where near-blizzard conditions may be possible for a few hours Thursday morning. Snow is expected to move into Winnipeg this evening with about 5 cm possible by Thursday morning. As the snow tapers off, winds will pick up from the north behind this system with gusts to 60 or 70 km/h Thursday morning giving blowing and drifting snow along with falling temperatures. As a result, be prepared for poor travelling conditions Thursday morning and allow extra time for the commute into work or school. Conditions should be improving by Thursday afternoon as a ridge of high pressure builds into western MB.
Monday, December 10, 2007
Dry and cold weather will dominate the weather picture today and Tuesday with highs in the minus teens both days. On Wednesday, an Alberta clipper will track into southern MB bringing milder temperatures into Southern MB, with highs of minus 7 predicted for Winnipeg by afternoon. If so, this would be the "mildest" day in Winnipeg since Nov 25th (over two weeks ago) when we hit -4C. This clipper will also bring an area of snow with it, likely spreading into Winnipeg from the northwest by evening. As the clipper passes into NW Ontario Wednesday night, snow will move through Winnipeg with up to 5 cm possible by Thursday morning along with gusty northerly winds developing. As a result, be prepared for a possible slow commute into work or school Thursday morning. Colder and drier conditions are expected for Thursday and Friday with highs on Friday only around minus 18. Long range models are hinting at a trend towards normal or even above normal temperatures next week.. but we'll have to see if those models continue with that trend over the next few days. Until then.. stay warm!
Monday, December 03, 2007
After this weekend's brush with a Colorado low to our south, Southern MB will get more snow from an Alberta clipper system moving in from the west overnight into Tuesday. Some light snow is falling across southern MB today, but the main action is expected over Southern SK tonight moving into southern MB overnight into Tuesday as the clipper system becomes better organized. Current projections call for the bulk of the snow (10-15 cm) to fall across SW Manitoba south of a line from Swan River to Emerson continuing south into North Dakota (including Grand Forks and Fargo again). Winter storm watches are in effect for these areas, which will likely be upgraded to snowfall warnings later today. Winnipeg and Southeast MB should be on the eastern fringe of this system, but we could see about 5 cm of snow beginning early Tuesday.. which is all you need to make for poor travelling conditions.
Winter appears to be making up for its slow start in a hurry this year!
Saturday, December 01, 2007
Here in Southern MB, the snow has pushed as far north as Morris as of 9:30 am and should continue to spread north into Winnipeg by midday or early afternoon. It looks like Winnipeg should stay on the northern fringe of this system with perhaps 2 to 4 cm of snow this afternoon through tonight. Higher amounts of 5 to 10 cm are possible south and east of the city including Morris, Steinbach, Emerson and Falcon Lake, with 10 cm or more over Northwestern Ontario. Expect deteriorating driving conditions this afternoon into tonight, especially south and east of Winnipeg. Improving conditions are expected Sunday as the storm departs the region overnight.
Thursday, November 29, 2007
Tuesday, November 27, 2007
Monday, November 26, 2007
A little more snow on the way today.. Turning colder tonight. More snow Tuesday night.
A weak clipper system over southwest MB this morning will track across North Dakota today bringing an area snow across southern MB. The snow has spread into the Portage area as of 10 am and will move into Winnipeg by midday. About 2 cm of snow can be expected this afternoon before the snow ends, with poor visibility at times and locally slippery driving conditions especially south and west of Winnipeg where the snow may be heavier at times. As the snow ends later today, brisk northerly winds will develop bringing in a surge of colder air from central MB where temperatures are currently in the minus 20s. Cold air will flood across southern MB tonight with wind chills dropping to the -30 range. Tuesday will start off clear and cold but another Alberta clipper system will spread cloud in during the day with another batch of snow developing from the west by afternoon. Look for this snow to spread into Winnipeg by Tuesday evening, with another 3 to 5 cm of snow likely Tuesday night into early Wednesday. As this system moves east, cold air will once again be reinforced across southern MB for the end of the week. Like it or not.. winter has arrived in southern MB.
Sunday, November 25, 2007
Friday, November 23, 2007
We had another light dusting of snow today in
1928 .................... TR
1939 ................... 0.5
1976 ................... 1.5
1912 ................... 2.5
1981 ................... 2.5
1916 ................... 2.8
1982 ................... 3.2
1913 ................... 4.1
1961 ................... 4.1
So does this slow start to the snow season mean anything for December? Well, if we look at the top 20 least snowy Novembers in
Wednesday, November 21, 2007
Sunday, November 18, 2007
Speaking of warnings.. a freezing rain warning has been issued for southwest MB this morning. A band of freezing rain and wet snow has moved into southwest MB from Saskatchewan and will affect those areas for a couple of hours this morning. The precipitation band is expected to move into Winnipeg and the Red River valley by midday. By that time, our temperatures should be above freezing so the precipitation should fall as rain or wet snow. However if our temperatures are still near or below freezing by that time, a brief period of freezing rain is also possible here.
Saturday, November 17, 2007
Whatever the case, this won't be a major snowstorm and snowlovers are getting anxious for a good snow to develop here in southern MB. The ground is still bare, and in many areas the grass is still green indicating ground temperatures are still above freezing. And long range models are not indicating any major snowbearing systems through next week over southern MB. Things can change of course, but at this point, it appears that November 2007 is following the trend of most of our winters over the past decade.. a slow start with below normal snowfall to start off the season. Could this be our new normal?
Tuesday, November 13, 2007
Winnipeg has hit a record 17C today.. eclipsing the former daily high of 16.3 set back in 1999. We are currently the warmest spot in the country and it's only 11am! But a cold front will push through by the lunch hour, and temperatures will begin sliding down this afternoon, while winds will be picking up from the west, with gusts to 80 km/h or more this afternoon. Watch out for flying garbage cans!
Monday, November 12, 2007
Speaking of which.. there will be a change in the weather over the next few days, although the main story will be winds, not snow. A deep storm system moving across the northern Prairies will draw strong southerly winds to 60 km/h over southern MB Tuesday morning, shifting to strong westerly winds to 70 km/h or higher in the afternoon as a cold front moves through. Temperatures will once again be very mild Tuesday with highs peaking around 13C by midday.. but then watch for falling temperatures by Tuesday night as colder air moves in from the west. Strong northwest winds will continue Tuesday night through Wednesday along with temperatures near freezing. There could be some flurries Tuesday night and Wednesday, but at this point, there's still no signs of a significant snowfall over southern MB over the next week or so.
Sunday, November 11, 2007
Friday, November 09, 2007
A rare occurrence of "thundersnow" occurred in Winnipeg last night as a weather system tracked across Southern MB, bringing the season's first general snowfall mainly north and east of Winnipeg. Around 11:45 pm a band of wet snow was moving through Winnipeg when a sudden flash of lightning generated a very loud thunderclap that some people mistook for an explosion. I was awoken by the thunder myself, and it was as loud as any close by summertime lightning strike, yet it was +1 and snowing at the time. I didn't see the flash, but many people reported one. Data from the lightning detector network indicates that the strike hit somewhere near the Eldridge/Oakdale area of Charleswood and generated 104,000 amps of electricity, which is a very powerful stroke. (normal lightning strikes generate about 20-40,000 amps) Note that this was the only strike recorded last night.. almost like the cloud built up all this static electricity, then released it all at once right over Charleswood! By the way, thunder is very rare around these parts during the cold season, with only 4 official occurrences between November and March in the last 50 years at Winnipeg Airport.
Thursday, November 08, 2007
A weak system over Saskatchewan is forecast to spread an area of snow into southern MB today which will move into the Winnipeg area by this afternoon or evening. Radar shows some light snow moving into western MB from Saskatchewan this morning. The snow will likely be melting on contact with the ground by the time it reaches Winnipeg as temperatures will be above freezing. There's even a chance the precipitation will mix with light rain if temperatures get warm enough (around +3 or +4C) For tonight, temperatures should remain steady near the freezing/melting point, so any snow that falls will likely be melting however we could see a slushy accumulation of 1 or 2 cm mainly on grassy surfaces tonight. There's a better chance of some accumulating snow north of Winnipeg through the Interlake areas where temperatures will be a little cooler and the main precipitation axis is forecast. The system is expected to exit southern MB overnight with drier conditions for Friday.
Saturday, November 03, 2007
Thursday, November 01, 2007
Some links to monitor the progress of Noel..
NOAA Hurricane Center
Canadian Hurricane Center
Cape Cod Weather
Dry but cool weather is expected through the middle of next week before a potential for another snowfall late next week into next weekend. Looks like winter will finally be making an appearance next week over Southern MB!
Sunday, October 28, 2007
Saturday, October 27, 2007
Contrast this to the Winnipeg airport site, which had a frost as late as May 27th (-0.1c) and as early as Sept 14th (-1.4c) for a growing season of only 108 days, almost half the length of downtown. This shows the large difference in nighttime temperatures between the more open rural areas around the egde of the city, and the more urbanized downtown core.
Here at my station in Charleswood, the official growing season lasted from Apr 26th to Oct 14th, or 142 days.. a good average for the city in general. This just goes to show how basing the growing season solely on the Winnipeg airport site can be very misleading!
Wednesday, October 24, 2007
Monday, October 22, 2007
By Wednesday a more potent system coming off the Pacific is forecast to track across far northern SK moving north of the MB/NU border on Thursday. This system is forecast to deepen into an intense storm over Hudson Bay on Thursday into Friday, with very strong northwest winds and blizzard conditions possible over the Hudson Bay coastline including Churchill and much of the Kivalliq region of Nunavut. South of this intensifying storm system, gusty south to southwest winds will bring milder conditions over the southern Prairies by Wednesday with temperatures climbing to the 20 degree mark over southern SK and southwest MB on Wednesday. Look for gusty southerly winds of 40 to 60 km/h or more over the Red River valley on Wednesday with highs in the mid teens. The milder weather will be short lived however as gusty northwest winds on the backside of the intense Hudson Bay storm drives cooler weather across the eastern Prairies for the end of the week.
Saturday, October 13, 2007
Rob's Weekend Forecast for Winnipeg..
TODAY.. Morning fog patches with locally dense fog giving near zero visibility at times. Otherwise mainly sunny and a lot more pleasant today than recent days. Little or no wind. Highs around 14c.
TONIGHT.. Increasing clouds. Calm winds. Lows near zero.
SUNDAY.. Slight chance of a morning shower otherwise morning clouds giving way to sunshine. Light winds. Highs near 14C.
Wednesday, October 10, 2007
For the northern Plains/southern Prairies.. there is essentially an equal chance of either below/near or above normal conditions this winter.. i.e. a non-forecast. In other words, there is no clear signal how this year's La Nina will affect the southern Prairies one way or the other. If indeed the general synoptic pattern sets up as described above, then there would be a greater likelihood of below normal temperatures this winter over the Prairies, especially the western Pariries, with perhaps above normal snowfall over the eastern Prairies closer to the storm track.
Here in Winnipeg, our last extended La Nina occurred from mid 1998 to early 2001. During those winters,
1998-99… generally warmer than normal.. especially February and March.
1999-2000.. Generally much above normal..with near normal January. (snowcover was gone here by end of February)
2000-01... A real see-saw winter. Third coldest December on record, followed by a mild January then cold February
2001-02.. Generally warmer than normal, cold March
So as you can see, La Nina doesn't necessarily equate to a cold winter here, at least in the eastern Prairies. One also has to consider the remarkably low Arctic sea ice cover recorded this year (an all time low), which presumably would tend to delay the onset of deep and persistent Arctic airmasses in the far north. That could mean a delayed start to winter over the Prairies, before colder than normal conditions set up for the latter half of the winter, mainly over the western Prairies. If that storm track is further north, then Alberta could see a snowier than normal winter with storms off the Pacific, with above normal temperatures more likely over the eastern Prairies.
A TV meteorologist in the US has produced an analog map showing temperature/precip anomalies based on previous La Nina years back to 1950. It supports above normal temperatures in the southeast US, and colder than normal temperatures over the north/northwest US including the southern Prairies.
So there are hints that perhaps we'll see colder than normal conditions at some point this winter, but there are also conflicting signals that reduce confidence in this outlook, especially in light of warming trends in our winters over the past decade and this year's record low Arctic ice cover.
NOAA will update their winter outlook on October 18th and Nov 15th.
Sunday, October 07, 2007
Thursday, October 04, 2007
Saturday looks interesting as the storm system sharpens over the US midwest sending a pronounced warm frontal tough towards southern MB. This warm front will mark the leading edge of much warmer air which will be surging north into North Dakota and Minnesota on Saturday. The front may push into extreme southeast MB on Saturday with 25C temperatures possible along the US border. At this point, it appears Winnipeg will stay on the cool side of this front with temperatures in the mid teens. However if the front pushes far enough north Saturday afternoon, Winnipeg may get into the low 20s (as current forecasts suggest) The frontal trough will move east Saturday night into Sunday with showers and possible thunderstorms over southern MB with locally heavy rain possible. Another system threatens showers for Monday.
Summing up.. unsettled Saturday with showers over southwest MB and the interlake - drier with a warming trend over southeast MB. Showers and thunderstorms Saturday night with locally heavy rain possible. Showers ending Sunday. A few showers possible Monday. Have a good long weekend whatever the weather!
Saturday, September 29, 2007
Monday, September 24, 2007
East St Paul........................ 27 mm
Sanford........................... 26.9 mm
Downtown (U of W)..............25.1 mm
Charleswood (Rob's Obs)...... 22.1 mm
St Vital........................... 21.6 mm
Downtown (Forks) ..............20.0 mm
U of M ag station ............... 19.8 mm
Transcona........................... 18.9 mm
River Heights..................... 18.8 mm
Charleswood (PJ school)....... 18.3 mm
Whyte Ridge.......................... 16.0 mm
Winnipeg Deer Lodge ........... 15.7 mm
Fort Whyte Center................ 15.2 mm
Bird's Hill................................. 10.8 mm
Stonewall............................... 7.6 mm
Sunday, September 23, 2007
For tonight a band of showers and possible thunderstorms is expected to move across southern MB from the southwest. Models are suggesting between 10 and 20 mm of rain over much of the Red River valley by morning including Winnipeg with some locally heavy rain at times thanks to embedded shower or thunderstorm activity moving up from North Dakota. Hopefully, this rain materializes and doesn't miss us, as has been the case the past couple of months. Look for a blustery and much cooler day Monday with cloudy skies, occasional light rain or drizzle, and temperatures only around 10C. Welcome to the roller coaster weather of fall!
Wednesday, September 19, 2007
Tuesday, September 18, 2007
Note that tornado ratings are based on the most intense damage found within the track of that tornado. It doesn't mean the tornado was always at F5 strength, but that it reached F5 at its maximum intensity. Note also that tornado strength is based on physical damage caused by the tornado. If a powerful tornado doesn't hit or damage anything, than it can only be classified as an F0 tornado.. no matter how strong it really may have been. As a result, there may have been other tornadoes in Canada that were F5 strength at some point, but they didn't hit any structures during that time to warrant an F5 rating. The Pipestone tornado that hit a day after Elie is a good example of this. This monster tornado is officially rated as an F3, however it didn't hit anything structural at its maximum intensity, staying mostly over open fields and forests at its height (good thing too!)
Monday, September 17, 2007
Sunday, September 16, 2007
Nonetheless, you have to figure something is definitely changing up in the Arctic, and a continual reduction of the Arctic ice cover will have major impacts on our climate, sea levels, and economy (with the possible annual use of the Northwest passage) One of the impacts of a reduced Arctic ice cap is that winters would generally be starting later, and we have certainly seen this in southern MB with 8 of our past 10 Decembers warmer than average. So it does appear that we're already seeing some impacts of this exceptional loss of Arctic ice with delayed, shorter, and less severe winters.
It's interesting to note that Winnipeg had its warmest January on record in 2006, following the last record low Arctic ice cover in the fall of 2005. Will this mean we will have another record mild winter this year? Well, it's tough to say since there are other factors which can influence our winters such as a developing La Nina, and other global climatic oscillations. However, one has to certainly consider that there is a good possibility of another warm winter coming up for Southern MB given this year's amazing loss of Arctic sea ice.
Thursday, September 13, 2007
For this afternoon and evening, models indicate low level steering winds should become more northerly, with a 330-350 orientation which should push the Lake Manitoba bands westward through Elie and Sanford and areas west. A 330-340 band off Lake Winnipeg would affect the Patricia Beach and Beausejour areas. (see example of 330 degree squalls from last October) I expect the bands to intensify this evening and tonight off both Lake Manitoba and Lake Winnipeg as a cold pool of -5C air at 850 mb moves over southern MB. This will give a 20C temperature differential between the lake water and 850 mb temperatures, which is getting extreme for lake effect precipitation (you need a minimum differential of 13c for lake effect initiation). There's even a chance that the precipitation could mix with or change to wet snow tonight into Friday morning, although I suspect the warm lake waters should maintain the precipitation mainly as rain.
The good news is that we should see a moderating trend this weekend with dry conditions and warmer temperatures as this cold pocket of air moves east.
Lake effect update.. Interesting to see squalls starting to re-orient themsleves this afternoon as low level winds become more northerly. The 300 degree rainbands off Lake Manitoba which had been affecting Winnipeg are now weakening, while a new 330-340 band sets up further west between Elie and Portage. See attached Doppler radar image from 12:20 pm showing this lake effect transition in progress. Note also lake effect bands starting to develop off Lake Winnipeg.
Wednesday, September 12, 2007
Thursday night will be downright cold as 850 mb temperatures plunge to -5C. This will be cold enough to possibly generate.. wait for it.. SNOW, especially over higher elevations of Southern MB! In addition, the cold air moving over the warm lake waters (currently running around 16 to 18C over the south basins) will generate bands of lake effect precipitation to the south and southeast of Lakes Manitoba and Winnipeg Thursday night into Friday morning. The warm lake waters should keep the lake effect precipitation as rain, however there is a chance that if the instability is deep enough and the bands are intense, the lake effect precipitation could change to wet snow.
Yikes.. a little too early to be talking about the S word!
Tuesday, September 11, 2007
With such a cool airmass in place, it would seem likely that frost would be a concern for tonight.. However, a storm system from the west is expected to bring increasing clouds overnight with increasing southeasterly winds that should minimize the threat of frost over southern MB tonight. However, look for a chilly evening with patchy frost possible mainly east of Winnipeg. This storm system by the way may bring the season's first snowfall over central AB and SK tonight through Wednesday night!
No doubt about it.. fall is here!
Thursday, September 06, 2007
Thursday, August 30, 2007
Tuesday, August 28, 2007
This new CWB network of weather stations will be growing significantly over the next couple of years, with the goal of several hundred stations being set up across the Prairies at local agriculture sites, farms, schools, etc. See previous blog entry for further details on this initiative.
Sunday, August 26, 2007
Thursday, August 23, 2007
Tuesday, August 21, 2007
As bad as this storm was, it could have been a lot worse had the storm come ashore about 100 miles north which would have caused billions of dollars in damage to the many resorts around Cozumel and Cancun.
Sunday, August 19, 2007
Friday, August 17, 2007
Thursday, August 16, 2007
The new weather network, launched Wednesday by U.S.-based WeatherBug in partnership with the Canadian Wheat Board and James Richardson International (JRI), will provide clients with more localized weather information -- from temperature and wind speed to humidity and precipitation -- that will be updated every five seconds.
WeatherBug president Bob Marshall said Wednesday's launch, at a research farm owned by JRI just south of Winnipeg, is the first step in building a national network of more than 1,000 stations that will benefit farmers, schools, emergency managers, businesses and media outlets. "We have the technology to revolutionize the way weather information is gathered and shared in Canada," said Marshall, whose company operates 8,000 weather stations in the United States.
Click here for complete article.
CWB weather station project website
CWB station map plot
Real time weather data from CWB rooftop station (includes webcam)
This is great news... a bold new private sector initiative to get lots of real time weather monitoring stations on the ground. This will help provide invaluable mesoscale weather information to fill in the gaps in Environment Canada's limited (and possibly shrinking) network of surface stations. The biggest benefit from this type of expanded network will be the ability to monitor real time rainfall measurements to the forecast and agricultural community, but local effects with wind and tempertaure will also be valuable information. Great to see! By the way, I see some of those Weatherbug weather stations are actually rebranded Davis Vantage Pro stations (which is what I have).
Wednesday, August 15, 2007
Tuesday, August 14, 2007
Monday, August 13, 2007
This brings us to the upcoming Atlantic hurricane season which should become more active in the next few weeks. NOAA is still predicting an above average year for tropical storms, with 7-9 hurricanes predicted, 3-5 which could be categorized as major (at least Cat 3). As of today, a new tropical wave has developed off the African coast which could become the season's 4th named storm (Dean) over the next few days. For good information on what's developing in the tropics, I highly recommend Weather Underground's tropical website, and Dr Jeff Master's blog to keep abreast of the latest developments regarding tropical storm activity.
Friday, August 10, 2007
The following are the preliminary severe events in Manitoba reported to Environment Canada up to 4 AM Friday.
Time of event location of event event type and comments
============= ================= =======================
4:05 PM .... Narol - Nickel sized hail
4:23 PM ..... pine ridge golf course - loonie sized hail
4:24 PM ..... Oakbank - Nickel sized hail
6:30 PM ..... 6 km west of San Clara - golfball sized hail
8:05 PM ..... Roblin - golfball sized hail
8:15 PM ..... 32 km nw of Dauphin - loonie sized hail
8:33 PM ..... Dauphin - 56 mm of rain in just over one hour.
8:44 PM ..... Dauphin - baseball sized hail. Extensive damage to cars, buildings and crops. Virtually every roof and car left outside in Dauphin suffered hail damage. Hail damage will likely exceed $50M. One of the most severe storms ever to affect area.
8:50 PM ... 8km south of Grandview - hen-egg sized hail.
9:20 PM .... Gilbert Plains - loonie sized hail.
9:35 PM .... Ste. Rose - Nickel sized hail.
10:15 PM ... 7 km east of Alonsa - golfball sized hail.
11:50 PM ... Delta beach - wind gust to 117 km/h.
1:15 to 1:30 AM .... Winnipeg - numerous reports of nickel to loonie sized hail and strong winds. Winnipeg airport had peak wind gusts of 100 km/h. Northern half of city was most affected with many trees down. One of the "top 10" storms for tree damage according to city forester. About 30 mm of rain fell over the north end of the city while areas south of Portage Ave received little or no rain.
Monday, August 06, 2007
Wednesday, August 01, 2007
July 2007 was marked by a distinct split personality.. the first half of the month featured generally normal temperatures and rainfall with no major extremes. The second half of the month however was marked by very hot and humid conditions and a lack of rainfall, with 2 heat waves to end the month that saw temperatures in the mid 30s and humidex values in the mid 40s. From the 17th to the 31st, the mean temperature at my location was 24C, some 4 degrees above normal. This compares to the first two weeks of the month which averaged a normal 20C. The result was a month that finished about two degrees above normal, but was considerably biased by the warm second half. The average high temperature in the last two weeks was a sizzling 31.3c, thanks to 8 days of 30+ temperatures, including a 35c reading on July 25th that was accompanied by Winnipeg's hottest humidex on record.. 48C thanks to a dewpoint of 26C at the time. The same day saw Carman, MB set a national humidex record of 53C thanks to an incredible 30c dewpoint.
Rainfall for the month was generally near normal with about 70 mm at my location (60 mm at Winnipeg airport). However, the rain was mainly concentrated in the first half of the month, with about 50 mm in the first two weeks spread over 5 or 6 rain events. The second half of the month saw only one rain event, when about 20-25 mm of rain fell during thunderstorms on the 25th that brought an end to the month's first heat wave. The hot dry weather has started to produce heat stress in area crops with depleting soil moisture, a considerable change from the wet conditions experienced during May and June.
All in all.. a sizzling end to a warm July.
Tuesday, July 31, 2007
Monday, July 30, 2007
Note also several other smoke plumes from forest fires over western Montana and the BC/Alberta border.. a result of several weeks of hot dry weather that has baked the upper Rockies and western Prairies. Forest fires have also been a problem over northern MB as well this month.
Saturday, July 28, 2007
Wednesday, July 25, 2007
HOT AND MOIST AIR FROM THE CENTRAL UNITED STATES CONTINUED TO FLOW INTO SOUTHERN MANITOBA ON WEDNESDAY. THE HIGH TEMPERATURES COMBINING WITH THE EXTREME HUMIDITY LED TO RECORD HIGH TEMPERATURES AND RECORD HIGH HUMIDEX VALUES OVER SOUTHERN MANITOBA TODAY. WINNIPEG SET AN ALL TIME RECORD FOR THE HIGHEST HUMIDEX READING EVER RECORDED AT THE WINNIPEG AIRPORT. HUMIDEX VALUES PEAKED AT 47 LATE THIS AFTERNOON BREAKING THE ALL TIME WINNIPEG RECORD OF 46.1 SET BACK ON JUNE 27, 1996. AS WELL CARMAN, MANITOBA UNOFFICIALLY SET AN ALL TIME CANADIAN RECORD HIGH HUMIDEX WHEN VALUES CLIMBED TO 53 LATE THIS AFTERNOON, BREAKING THE RECORD PREVIOUSLY HELD BY WINDSOR, ONTARIO OF 52.1 SET ON JUNE 20, 1953.
THE HUMIDEX IS AN INDEX (A COMPUTED VALUE AS OPPOSED TO SOMETHING MEASURED) DEVISED TO DESCRIBE HOW HOT OR HUMID WEATHER FEELS TO THE AVERAGE PERSON. THE HUMIDEX COMBINES THE TEMPERATURE AND HUMIDITY INTO ONE NUMBER TO REFLECT THE PERCEIVED TEMPERATURE. IT TAKES INTO ACCOUNT THESE TWO IMPORTANT FACTORS TO BETTER DESCRIBE HOW STIFLING THE AIR FEELS THAN EITHER TEMPERATURE OR HUMIDITY ALONE.
THE FOLLOWING ARE THE UNOFFICIAL NEW MAXIMUM TEMPERATURE RECORDS AS OF 5:00 P.M. WEDNESDAY JULY 25.
GILLAM 28.8 28.1 1983
PINAWA 34.3 34.0 1989
GRETNA 33.2 32.2 1961
CARMAN 34.0 28.1 1997
THE FOLLOWING ARE LOCATIONS THAT CAME CLOSE TO BREAKING THEIR MAXIMUM TEMPERATURE RECORDS.
GIMLI 32.1 33.1 1989
ISLAND LAKE 29.6 29.7 1989
THOMPSON 27.4 28.7 1989
CHURCHILL 28.2 30.0 1929
FISHER BRANCH 30.5 32.2 2003
WINNIPEG 35.3 36.7 1931
Tuesday, July 24, 2007
Relief however is on the way on Wednesday. A heat-wave ending cold front will be coming through by midday or early afternoon. So after another warm and muggy morning with temperatures peaking at 32C by midday, winds will shift into the northwest in the afternoon sending temperatures and humidex values down. By evening, temperatures will likely be down to the 25C mark, and 20c by midnight with lows of 16C by morning. In addition, the cold front will likely be accompanied by showers and thunderstorms that could bring locally heavy rainfall and possibly some severe winds or hail. Look for more comfortable conditions and seasonably warm temperatures for Thursday into the weekend.
Tonight will be another warm one.. with a low of only 25C, maybe even 26 or 27C as we get a southerly breeze all night. If so, that will be Winnipeg's second warmest minimum temperature on record (warmest minimum was an amazing low of 28.3C on July 12 1936 following Winnipeg's hottest day ever of 42.2 on July 11) However, that low of 25C will likely not be the minimum for Wednesday. The heat-wave ending cold front will be coming through by midday, so temperatures will be dropping noticeably in the evening, likely below 25C by midnight.
Monday, July 23, 2007
By the way, I replaced the barometric graph plot on my main page with a dewpoint/heat index plot to better gauge how sticky it is over the next few days.
Sunday, July 22, 2007
And it looks like the hot humid weather will continue for the next 2 to 3 days before a cold front brings more comfortable conditions by Wednesday evening. Until then, expect more of the same as today with afternoon temperatures of 32 to 35C, and humidex values of 40 to 45C. Stay cool!
By the way, you may notice that my weather station displays "heat index" rather than the humidex. The "Heat Index" as shown on my station is an equivalent temperature based on air temperature and humidity (or more accurately, the dew point). It is similar to but NOT the same as the Canadian "humidex" value, which employs a slightly different equation and gives different results than the American "Heat Index". Generally the Heat index will register about 3-5C lower than the humidex. My station can only display heat index. A simple way of calculating the humidex is to add the temperature and dewpoint (in C) then subtract 13. For example, if the air temperature is 32C and the dewpoint is 22C then the humidex is 41C (32 + 22 - 13 = 41C) Environment Canada issues humidex advisories when humidex values of 40C or greater are expected. Whatever the case, both indeces are designed to tell you how hot it "really" feels based on the moisture content of the airmass. The basis for this is that when it's humid, it becomes harder for the body to cool since evaporation from the skin (i.e sweating) is less efficient. Thus, 30C with 60% humidity will feel "hotter" than 30C with 30% humidity because the body will not be able to cool as quickly at higher humidity levels. In reality, it's not any hotter, it's just more uncomfortable.
The dew point is the best indicator of how humid or "sticky" an airmass is. The following table gives a rough idea of dewpoint and comfort of an airmass..
< 10C ..............dry
15-17C ............moderately humid, still comfortable for most people
18-21C ............humid, uncomfortable for most people
22-24C ............very humid, uncomfortable for everyone
>24C ..............oppressive, stifling
In our latitudes, dewpoints above 24C are rare although they do occur sometimes in southern MB in the growing season due to contribution from evapotranspiration from plants and crops. Dewpoints of 27C or more are usually only found in tropical areas near warm oceans.
Wednesday, July 18, 2007
Officially, a heat wave is defined as a period of at least 3 consecutive days with maximum temperatures of 32C or greater. This is a throwback from the Fahrenheit days when we used 90F (32C) to define a "hot" day. Unofficially, we have started to define a heat wave in Canada as a period of 3 days or more with maximum temperatures of 30C or more. It's a nice round number, and it's a good threshold for most Canadians to define as a "hot" day. Either way you slice it, it looks like an extended period of hot weather is coming to southern MB!
Tuesday, July 10, 2007
PILOT MOUND............ 57.2 MM
EMERSON................ 52.0 MM
GRETNA................. 50.6 MM
MORDEN................. 45.8 MM
STEINBACH.............. 36.6 MM
CARMAN................. 29.4 MM
SPRAGUE................ 27.0 MM
WINNIPEG (ST VITAL)...... 26.2 MM
Whyte Ridge ............. 20.4 MM
Charleswood (Rob's Obs).. 16.5 MM
WINNIPEG (AIRPORT)....... 10.5 MM