Wednesday, December 30, 2009
Top 10 weather stories of 2009
Friday, December 25, 2009
Snow and blowing snow moving into southern MB.. travel conditions to worsen
Thursday, December 24, 2009
Snow event begins.. 10-25 cm likely over southern MB through Christmas
Monday, December 21, 2009
Winter storm threatens holiday travel plans for areas south and east of Manitoba
UPDATE: Dec 22: Winter storm watches have been posted for all of North Dakota and Minnesota right to the Canadian border for the potential of heavy snow beginning Wednesday and continuing through Christmas Day. Latest guidance indicates some snow will be moving into southern MB from this system as well Thursday into Friday although the heaviest amounts are still expected south of the border. Stay tuned..
Saturday, December 19, 2009
Snow drought continues
Wednesday, December 16, 2009
Arctic chill easing.. moderating temps on the way
Monday, December 14, 2009
Windchill is not a temperature!
For example, let's say it takes 20 minutes for you to feel cold when it's -25C outside and no wind. And let's say it takes you 10 minutes to feel cold when it's -40C with no wind. Now, let's say it's -25C with a 30 km/h wind. Because of the wind, your body starts losing heat more quickly, and you start feeling cold after only 10 minutes. Your body will tell you, hey it must be -40C out here because it took 10 minutes for you to start feeling cold. But is it -40C outside? No, it's -25C. To you, it just feels like -40C because of the wind that accelerated your body's heat loss. People will say it "feels like" -40 with the windchill.. which is a way of saying that the wind makes it feel colder than it actually is.
Because of this, windchill should never be stated as a temperature value (like degrees C).. it really should be expressed as a cooling rate (e.g. -58.4CU "cooling units") but in Canada, it's officially displayed without any units. Media has become overly fascinated with the windchill (I guess because it sounds so much worse than the actual temperature!) to the point that often they're just giving windchill values instead of the actual air temperature! The problem with this is that people start quoting windchill values as actual temperatures (as in the Sun article), which they are not.
Temperature is a measure of how much heat energy a parcel of air holds. The more heat energy, the higher the temperature. Windchill on the other hand is an index that estimates the RATE of energy loss of an air parcel given its original heat energy AND a prevailing wind that helps to accelerate the amount of energy leaving the air parcel (i.e. cooling rate). So, temperature is the amount of heat energy an air parcel has.. windchill is the rate of cooling of that air parcel.
Look at it this way... You have a bucket of water at +5C. You put it outside, where the air temperature is a constant +2C, but a wind of 50 km/h is producing a windchill of -5. Will that bucket of water freeze? Of course not. The water will only cool down to the ambient air temperature.. +2C. It can't get any colder than its environment unless it's cooled by some other method (e.g. refrigeration) The windchill of -5 merely implies that the water will cool down to +2C at a rate equivalent to that if the water was outside at -5C with no wind. So instead of taking one hour to cool down to +2C, it will only take 10 minutes thanks to that 50 km/h wind. But the water temperature will never go below +2c, no matter how extreme the wind or windchill is. That's the effect of windchill. It describes an equivalent RATE OF COOLING, not an actual temperature. So if it's -20C with a -40 windchill, your car will likely still start if it's not plugged in because the battery will never get below -20C. On the other hand, if it's -40C with no windchill, your car will not start if it's not plugged in because the battery will cool off to -40C (given it's outside long enough). See the difference?
Before 2001, the Prairies used a windchill index that was given in watts/sq metre (e.g 1800 W/m2) This was a more scientifically valid measure of what windchill actually was.. a rate of cooling, expressed in the amount of energy loss in watts per square metre of area. However in 2001, the windchill was re-calculated and standardized for all of North America to the windchill index we use today, which was mainly based on the more common "equivalent temperature" index being used in Southern Ontario and the United States. A survey conducted at that time showed that most people found the watts/sq metre unit "too technical" a term to fully understand.
Saturday, December 12, 2009
You want snow?!
Friday, December 11, 2009
Cold.. and getting colder - Bitter windchills developing this weekend
Monday, December 07, 2009
Arctic cold descends on Prairies.. blizzard to affect central US Plains
Meanwhile a powerful blizzard is shaping up over the central US plains today, and will bring heavy snow and strong winds through Kansas, Nebraska, Iowa and southern Minnesota tonight into Tuesday.
Sunday, December 06, 2009
Balmy December weather 70 years ago
|Winnipeggers pose on the golf course on a rare|
snow free Christmas Day in 1939
Friday, December 04, 2009
Arctic blast pushing into Prairies
Wednesday, December 02, 2009
Cold winds and open lakes = snowsqualls for some tonight through Friday
UPDATE: see local radar image above from Thursday morning showing lake effect bands
November 5th warmest, 2nd driest on record
The big story however was the dryness of the month. Total precipitation at Winnipeg airport was only 1.5 mm .. tying 1901 and 1939 as the second driest November on record in Winnipeg (driest was 0.8 mm in 1976) All of the precipitation fell as melted snow with no rain during the month. The month was dominated by almost daily sunshine and mild temperature from the 4th to the 24th.. making it feel more like October than November. The extended fall weather and lack of snow allowed farmers to continue burning their fields well beyond the usual end date of Nov 15th.. requiring the province to extend the requirement for burning permits into December.
All in all.. a fabulous fall month.
Tuesday, December 01, 2009
Snowfall slipping south of city
Sunday, November 29, 2009
Alberta clipper threatens snow for Tuesday
UPDATE: Latest model guidance has shifted the track of Tuesday's system further south. As a result, the heaviest snow is now expected to fall over southwest Manitoba and over the southern Red River valley into SE Manitoba where 10-15 cm is possible. Winnipeg is expected to lie on the northern edge of the heaviest snow.. with 5 cm possible. Note that Winnipeg may get heavier amounts of snow if this system tracks a little further north than latest projections. Stay tuned..
Saturday, November 28, 2009
Above normal temps to end November.. colder weather to begin December
By Tuesday, an Alberta clipper system will track through the Manitoba lakes and bring a threat of snow, especially through the Interlake areas. Gusty northerly winds on the backside of the system will draw in colder temperatures over southern MB by Tuesday evening, with temperatures finally dropping to normal or even below normal values for the beginning of December (normal highs -7C, normal lows -15C)
Tuesday, November 24, 2009
Sliding towards normal..
Sunday, November 22, 2009
Gusty Saturday sets new record high in Winnipeg
Friday, November 20, 2009
Dry spell entering 3rd week
UPDATE: Winnipeg ended up with 1.5 mm for the month, tying 1901 and 1939 as the second driest November on record. Meanwhile, Port Alberni ended up with over 800 mm for November while Tahsis Village on the northwest coast of Vancouver Island ended up with over 1100 mm for the month!
Thursday, November 19, 2009
US climate experts predict mild weather continuing through December
Saturday, November 14, 2009
Fine fall weather to continue through upcoming week
Thursday, November 12, 2009
Double digit streak goes to 7 days.. 2nd longest on record for November
The top streak of 10C days in November in Winnipeg..
1. 8 days.. 1963 Nov 2-9 .. max 13.9C
2. 7 days.. 2009 Nov 6-12.. max 13.8C
3. 6 days.. 1975 Nov 1-6 .. max 23.9C
4. 5 days.. 1904 Nov 2-6 .. max 18.3C
4. 5 days.. 1899 Nov 2-6 .. max 15.6C
4. 5 days.. 1923 Nov 8-12.. max 14.4C
The most number of 10C days in a November in Winnipeg is 11 days in 1904 followed by 10 in 1981.
Monday, November 09, 2009
October in November continues
Friday, November 06, 2009
Temperatures hit the 20C mark over SW Manitoba
* from CWB Weatherbug mesonet
see also stats from MB Ag-Wx mesonet
Monday, November 02, 2009
Nice warmup by week's end
Models are indicating a nice warmup over southern MB by the end of the week, as a low pressure system moves across the northern Prairies spreading a mild Pacific airmass across much of the south. In southern MB, sunny skies and temperatures of 10 to 13C are likely by Friday into Saturday, well above the normal highs of +3C for early November. Temperatures will cool slightly for next week however long range guidance is suggesting that temperatures will remain near to above normal into mid November.
Wednesday, October 28, 2009
Intensifying storm system to bring strong winds, rain and snow to southern MB Friday
Sunday, October 18, 2009
Mild Sunday over southern MB
Friday, October 16, 2009
CPC winter outlook calls for milder than normal conditions for Prairies
See the winter outlook from NWS Grand Forks for a more detailed discussion on the weather influences and trends expected for the Red River valley area this upcoming winter.
Saturday, October 10, 2009
First snow of the season hits Winnipeg
Thursday, October 08, 2009
Heavy snow event shaping up for Riding Mountain/Dauphin area Friday
And although it's a little early in the season for a significant snowfall, it's not unusual. Just 4 years ago on October 5 2005, a record early season snowstorm dumped up to 45 cm of snow over southwest Manitoba near Pilot Mound area as well as North Dakota, with 5-10 cm in Winnipeg. Here's a list of the earliest October snowfalls of 2 cm or more in Winnipeg..
Oct 5 2005 ...... 5.0 cm (est)
Oct 9 2009 ...... 10.0 cm
Oct 10 1919
Saturday, October 03, 2009
Staying cool... snow possible by end of week
Thursday, October 01, 2009
System to bring rain south and west of Winnipeg
Wednesday, September 30, 2009
Spectacular September salvages sorry summer - September 2009 warmest on record
September 2009 was a summer-like month with plenty of sunny warm days, and only 4 days with measurable rain. The stretch between the 13th and 25th was especially nice, dominated by sunshine and 25-30C temperatures that was interrupted only one day with cloudy skies and a brief shower over the two week period. The month finished with an average temperature higher than any month of the year, the first and only time in Winnipeg’s climate history that September was the warmest month of the year. Every day from the 1st to the 27th was above normal with 19 of those days reaching a temperature of 25C or higher, the most 25C days of any September (previous record 16 days in 1940) and nearly twice as many as July had (10 days) Amazingly, no daily record highs were established during the month, highlighting the fact that it was the persistence of the warm weather that was the story, rather than any extreme heat. This was evident with the night-time lows, with no lows below 10C until the 22nd. A cool snap at the end of the month produced the season’s first frost on the 29th with a low of -2.4C at Winnipeg airport. Downtown however remained frost free all month.
Precipitation at the airport totaled 22 mm, less than half the average September monthly precipitation of 58 mm. Of the 22mm total, only 1 mm fell after the 11th. The sunny dry warm weather was a blessing for area farmers who needed an extended period of warm dry weather to make up for a slow growing season delayed by cool temperatures and rainfall. As a result, many crops were able to mature before the late frost, and be harvested in fine sunny conditions. The weather was also a boon to local beaches and golf courses, making up for some lost ground from a cool wet summer.
Overall, a September to remember! (see NCDC September summary for more info)
Tuesday, September 29, 2009
2009 growing season ends for most of southern Manitoba
At Winnipeg airport, the average date of the first fall frost is Sept 22nd so today's frost was a week later than "normal", although the first fall frost date varies quite a bit from year to year. Average date for the last frost in spring is May 23rd which gives an average growing season of about 121 days using airport data. Last year, the airport had a 116 day growing season (Jun 3rd - Sept 26th), virtually the same as this year.
Within the city of Winnipeg however, frost was not widespread this morning. The Forks downtown had a low of +1.4C, and in Charleswood, my station registered a low of +0.5C with just some some light frost noted. Downtown Winnipeg has a much longer growing season than the airport, due to the urban heat island effect that keeps night time temperatures warmer than rural areas. The average first fall frost downtown is Oct 5th, while the last spring frost is May 4th giving an average growing season of 159 days downtown, or 38 days longer than the airport. For most areas of the city, the length of the growing season lies somewhere between downtown and airport values.
Monday, September 28, 2009
Chilly today.. frosty tonight...
Friday, September 25, 2009
Strong winds to bring cool change for Sunday.. gales, high waves for MB lakes Sunday night
Wednesday, September 23, 2009
September sets new heat record... big cooldown expected Sunday
The warm weather has been persistent for the past 3 weeks over southern MB with every day this month above normal so far. But changes are on the way. A storm system is expected to cross southern MB Sunday, which will draw in much cooler air Sunday into Monday on strong northwest winds. This will bring the first spell of below normal temperatures in over 3 weeks, with the risk of a widespread frost by Tuesday morning. The cool outbreak however should not be enough to offset this September finishing as the warmest September on record in Winnipeg as well as most of southern MB.
Tuesday, September 22, 2009
Fall arrives.. but summer hangs on through the end of the week
Sunday, September 20, 2009
Summer in September!
Friday, September 18, 2009
Last official weekend of summer to be summer-like!
It looks like Mother Nature is trying to make up for her abysmal performance this summer with a glorious stretch of sunny warm weather heading into the last official weekend of summer. Temperatures have been above 25C all week long with sunshine, and the warm weather will continue through the weekend before a cold front moves through late Sunday. Saturday will see temperatures rise to the 30 degree mark over much of southern MB, especially over western MB where temperatures of 32C are forecast. Sunday will continue to be warm, with gusty southerly winds pushing temperature into the mid 20s before clouds approach in the afternoon and evening ahead of the advancing cold front. This front will usher in occasional showers Sunday night into Monday with a return to more seasonable temperatures in the upper teens. However, long range models are now indicating that the cooler weather will be short lived as above normal temperatures are forecast to return by mid to late week. This virtually ensures that September 2009 will likely go down as the warmest September on record in
Monday, September 14, 2009
Summer in September continues.. cooler weather next week
Friday, September 11, 2009
Drier weekend.. with above normal temperatures continuing next week!
Thursday, September 10, 2009
Showers/thunderstorms developing late today into tonight.. more rain Friday
Sunday, September 06, 2009
Showers and thunderstorms Monday night into Tuesday.. locally heavy rain possible
Friday, September 04, 2009
Summer like weekend.. cold front expected late Monday
Tuesday, September 01, 2009
Cool August ends 7th coolest summer on record
Looking at the 3 month temperature graph for the "summer" of 2009, one can see the only warmth was a 2 week stretch in June and a 4 day hot spell in mid August (the 33C reading on Aug 27th is erroneous) Cool weather dominated most of the summer, especially July which did not break the 30C mark.
August now marks the 9th consecutive month below normal in Winnipeg.. the longest such streak since another 9 month stretch between Dec 1949 and August 1950.
Top 10 Coolest summers in Winnipeg (records began 1873)
|YEAR||Jun||Jul||Aug||AVG (C) |
NORMALS 17.0C 19.5C 18.5C summer: 18.3C
Saturday, August 29, 2009
Nice week ahead!
Friday, August 28, 2009
Rob's Obs updating again
My website has been updated with weather data from my weather station in Charleswood, and I'll try to get the blog going again in the next few days.
Sunday, August 16, 2009
Sunday, August 02, 2009
New month... Same story
Saturday, July 25, 2009
Cool week to end cool month..
Monday, July 20, 2009
Still no hot weather in sight..
Not much change is expected for the rest of the month with the upper ridge expected to persist over BC (see attached 500 mb GFS prog for Friday) maintaining warm temperatures out west with near to below temperatures over the eastern Prairies. Although the absence of hot humid weather is a disappointment for beach and cottage goers in southern MB, the weather has been comfortable for most residents with the benefit of little or no need of air conditioning. As of July 19th, the mean monthly temperature in Winnipeg was 15.8C, putting it on pace for one of the coolest July's on record in the city since records began in 1872. The top two coolest Julys in Winnipeg were 1884 (15.4C) and 1992 (15.9C) Both those years followed major volcanic eruptions the previous summer (Krakatoa in 1883, and Pinatubo in 1991)
Thursday, July 16, 2009
Fall like weather to give way to nice weekend..
It’s a cool wet July morning out there with overcast skies, rain and temperatures only around 9C.. making it feel more like fall than mid summer. A low pressure system over northern
Wednesday, July 15, 2009
Heavy rain swamps Winnipeg.. again..
Sunday, July 12, 2009
Nice today and Monday.. more showers/tstorms Tuesday and Wednesday
more showers expected Wednesday across southern MB as the storm system moves east.
Thursday, July 09, 2009
Thunderstorms with torrential rain hit Winnipeg
Tuesday, July 07, 2009
Severe thunderstorms, heavy rain possible Wednesday night
Monday, July 06, 2009
Thunderstorm tracks over east Winnipeg
New website for Rob's Obs
Also note that jpg images from my site now have a “no_cache” added to the directory.. so if you have any links to Rob’s Obs .jpg images, be sure to add /no_cache after /robsobs to get the valid images.
Thursday, July 02, 2009
June 2009 weather stats for Winnipeg
After an unseasonably cool first half of the month, temperatures finally warmed to above normal values for the latter half of June as summerlike weather finally made an appearance over southern Manitoba. The warm weather however was not enough to offset the cool start, and as a result, June finished almost 1.5C below normal, with a monthly mean temperature of 15.6C at Winnipeg airport. This made June the 7th consecutive month with mean temperatures below normal (December 2008 to June 2009). Although significant this is not record breaking. Since 1971, there have been four other periods with 7 consecutive months of below normal monthly mean temperatures in Winnipeg, namely...
November 1973 to May 1974
June 1985 to December 1985
May 1993 to November 1993
November 1996 to May 1997
There were also two periods with 8 consecutive months below normal
November 1978 to June 1979
October 1995 to May 1996
The month was marked by an exceptionally late freeze on June 6th.. with a record low of -4.6C at Winnipeg airport.. the coldest June temperature ever at the airport since 1938, and the second coldest June temperature in Winnipeg since June 1 1888 (-6.1C) Downtown Winnipeg escaped the freeze with no frost reported at the Forks weather station.
A strong storm system on June 26-27th brought heavy rainfall and strong winds to southeast Manitoba with over 100 mm of rain in areas east and southeast of Lake Winnipeg. This system brought heavy rainfall to eastern sections of Winnipeg with 75 mm reported while western areas, including the airport, had 35 mm. Other than this system precipitation was generally light in June with a lack of showers and thunderstorms. As a result, precipitation varied greatly across the city in June. Whereas the Airport only had 61.5 mm, the downtown station at The Forks had 82.8 mm and according to the rain gauge network operated by the City of Winnipeg, there was over 90 mm in the many areas of Winnipeg east of the Red River. Normal June rainfall in Winnipeg is 90 mm.
Sunday, June 28, 2009
Heavy rains soak southern /eastern MB
A strong storm system brought heavy rainfall across southern MB June 26-27th. The storm began as showers and thunderstorms Friday the 26th with heaviest amounts across the southern RRV and southeast MB. The system then wound up as an intense low pressure system over northwest Ontario on the 27th, bringing a soaking wind-driven rain over eastern MB, with the heaviest rainfall over the Interlake and Whiteshell areas. Here is a summary of rainfall amounts over the past 2 days.
Official observations (EC)
Location storm total
Brandon - 11.0 mm
Carberry - 13.2 mm
Oakpoint - 24.6 mm
Pilot Mound - 27.8 mm
Winnipeg - airport - 31.2 mm
Portage la Prairie - 33.8 mm
Delta marsh - 35.2 mm
Deerwood - 36.4 mm
Sprague - 40.6 mm
Morden - 47.0 mm
Fisher Branch - 48.2 mm
Winnipeg - the forks- 50.6 mm
Gimli - 67.7 mm
Gretna - 72.2 mm
Carman - 75.2 mm
Great Falls - 92.0 mm
Pinawa - 94.6 mm
Location storm total
Altona - 85.0 mm
Arborg - 75.0 mm
Dugald - 78.4 mm
Elm Creek - 62.0 mm
Landmark - 99.8 mm
Letellier - 76.4 mm
Marchand - 92.7 mm
Morris - 85.2 mm
Portage la Prairie - 47.2 mm
Selkirk - 84.4 mm
St. Pierre - 101.8 mm
Starbuck - 36.4 mm
Steinbach - 82.0 mm
Teulon - 67.8 mm
Treherne - 55.8 mm
Winnipeg north - 59.0 mm
Winnipeg west - 35.0 mm
Winnipeg south - 55.0 mm
Winnipeg southwest - 38.8 mm
Woodlands - 48.8 mm
Thursday, June 25, 2009
Thunderstorms and heavy rain possible Friday night
Sunday, June 21, 2009
Sunny warm morning for Manitoba marathon
Sunny and warm weather conditions prevailed today for this year’s Manitoba Marathon, coinciding with the first official day of summer The race started at 7 am with temperatures at a comfortable 19c. However, the strong sun quickly warmed up temperatures to 24c by 9 am and 27c by 10:30 am with southerly breeze of 20 to 25 km/h. Humidity levels were moderate, with dewpoints around 15c. The conditions were a marked change from the weeks of below normal temperatures leading up to the marathon.