Sunday, November 29, 2009

Alberta clipper threatens snow for Tuesday

An Alberta clipper storm system is forecast to track across southern MB Tuesday, bringing the potential of the season's first significant snowfall over portions of southern MB. The center of the storm is expected to move across the Riding Mtn area early Tuesday tracking through the northern Red River valley and into the Whiteshell by Tuesday evening. The heaviest swath of snow is expected along and north of this storm track.. putting the most significant snow along and north of the TransCanada where 10-15 cm is possible. Snowfall amounts will drop off sharply south of this track with 5 cm or less likely. Gusty northwest winds will follow in behind the system bringing a drop in temperatures by Tuesday evening, as well as areas of blowing and drifting snow in open areas. Snowfall amounts will depend critically on the exact path of this system, so stay tuned on the progress of this potentially first wintery blast of the 2009-10 winter season.

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

The above normal temperatures that have characterized most of November will continue through the end of the month before a change to colder weather just as the calendar flips to December. In the short term, generally quiet weather is expected over the next few days with cloudy to partly sunny skies, and afternoon temperatures near or slightly above the freezing mark, some 6 degrees above normal for this time of year. November 2009 will end up as the 3rd or 4th warmest November on record in Winnipeg since 1872, and barring any measurable precipitation over the next 3 days, will likely end up as the driest November since records began with only 0.5 mm total precipitation for the month.

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..

It was another pleasant day of sunshine and above normal temperatures over Winnipeg and the Red River valley, but things will be cooling off Wednesday and Thursday, with colder weather likely for next week. Still, temperatures are forecast to remain above the normal high of -5C this week, before cooling off to more seasonable values next week. The return of colder air will also increase the chances for some precipitation, likely in the form of flurries or snow over the next few days. For tonight, some light snow is possible mainly over SW Manitoba with some flurries possible over much of southern MB Wednesday as brisk northerly winds pump in colder air. The next chance of precipitation will be Friday as a low pressure system moves through the Interlake spreading an area of snow mainly north of the low, mixing with some rainshowers to the south. Behind this system, colder air is expected for the weekend into next week with a possibility of some snow Saturday into Saturday night. Winnipeg has not seen any measurable precipitation since the 1st of the month, but the dry streak will likely come to and over the next few days as colder and more unsettled weather moves in.

Sunday, November 22, 2009

Gusty Saturday sets new record high in Winnipeg

The mild November of 2009 continued into its third week, with record breaking temperatures on Saturday. In Winnipeg, the high of 13.4C at Winnipeg airport set a new record high for Nov 21st, eclipsing the previous mark of 11.1C in 1904. It was also the 10th day this month of double digit temperatures, twice the number recorded in October, and tying 1981 for the second most double digit days in November. The record breaking day was also accompanied by strong southerly winds gusting as high as 76 km/h at the airport Saturday afternoon. Although slightly cooler weather is forecast over the next few days, temperatures are expected to remain above normal through mid week and possibly into next weekend before hints of a change to colder weather by the end of the month into early December. Until then, Winnipeg is on pace to record its warmest November on record. As of the 21st, the mean monthly temperature at Winnipeg airport was +2.4C, over 7 degrees above normal and a degree warmer than the record warmest Novembers of 1899 and 1923 at 1.3C.

Friday, November 20, 2009

Dry spell entering 3rd week

With sunny skies and no precipitation forecast for the next few days, Winnipeg will be entering its 3rd week without measurable precipitation officially recorded at Winnipeg airport. The airport weather station measured 0.5 mm of melted snow early on the 1st of the month, and since then there has been no precipitation recorded, 19 straight days as of today. And long range forecasts don’t offer much in the way of significant precipitation over the next 5 days, although there may be some flurries by the middle of next week as some colder air moves in. All in all, unless there's a significant storm at the end of the month, it’s shaping up to be one of the driest Novembers on record in Winnipeg since 1976 when only 0.8 mm fell during the month, the driest November on record. This is in sharp contrast to the west Coast which has been deluged with rain this month due to frequent Pacific storm systems coming onshore. Some localities have recorded over 500 mm of rain since November 1st, including Squamish, Tofino and Port Alberni.

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

NOAA's Climate Prediction Center (CPC) released its climate outlook for December today, and it shows that above normal temperatures are expected to continue through December over the the northern Plains (and southern Prairies) This outlook is very similar to CPC's November outlook which also called for above normal temperatures over the central continent. The mild weather outlook is mainly due to a strengthening El Nino which has now reached a moderate stage in the Pacific. This tends to bring warmer than normal conditions during the winter months over western Canada into the mid section of the continent. As a result, CPC is indicating better than even odds that the winter of 2009-10 will be above normal over our area. Precipitation is likely to remain below normal over us as well, as the North America storm track tends to take a "split flow" pattern during El Nino episodes. This split flow pattern brings a southern track of storms though the southern US (mainly California into the Gulf states) while a northern storm track affects BC into the northern prairies. This setup usually translates to drier and warmer than normal conditions over the southern Prairies between the two main storm tracks.

Saturday, November 14, 2009

Fine fall weather to continue through upcoming week

The exceptionally nice weather we've been enjoying this month will continue through the upcoming week with dry weather and above normal temperatures. Long range models continue to indicate Arctic air remaining well to our north, as a storm track takes storms across the northern Prairies or Territories, keeping mild Pacific airmasses over the southern Prairies. The result will be more of the same, with sunshine and temperatures in the 5-10c range through the next week at least.

Thursday, November 12, 2009

Double digit streak goes to 7 days.. 2nd longest on record for November

With temperatures hitting 11C today in Winnipeg, it marked the 7th day in a row of double digit highs in the city since last Friday. This is the 2nd longest streak of 10C days for November in Winnipeg since records began in 1872, second only to the 8 day streak from Nov 2-9, 1963. Note that we had only five double digit highs in all of October. The streak will end at 7 days as slightly cooler weather moves in Friday, however temperatures will remain above normal for the next week at least.

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

The fine late fall weather will continue for the next few days.. with double digits highs expected Tuesday and Wednesday before a frontal system brings in a chance of showers Thursday with slightly cooler weather for the end of the week. Temperatures however will remain above normal through the weekend into next week. In the near term, the mild 10+C weather will continue Tuesday, but gusty southerly winds will develop during the day with gusts to 60 or 70 km/h possible by the afternoon through the Red River valley.

Friday, November 06, 2009

Temperatures hit the 20C mark over SW Manitoba

Sunshine, snowfree ground and gusty south to southwest winds allowed temperatures to climb into the upper teens and low 20s across SW Manitoba today. The warmest spots were downwind of higher terrain with downsloping southwest winds coming off Riding Mtns and Turtle Mountain allowing temperatures to climb into the 20s.. well above the normal high of +2C this time of year. Temperatures were a little cooler in Winnipeg and the Red River valley thanks to a southerly valley wind, but were still well above normal. Some highs across southern MB today included..

Killarney....24.1C *
Dunrea.......23.8C *
Boissevain...23.4C *
Glenboro.....21.4C *

* 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.