Saturday, December 03, 2016

Mild weather continues into early next week.. then Arctic plunge moves in! Significant snow possible Tuesday.

The above normal temperature pattern which has persisted over southern Manitoba for the past 6 weeks will continue through the weekend into early next week.. but a major pattern change next week will bring an end to the mild weather as a strong push of cold Arctic air floods across the Prairies from the west.  This will bring the first real cold weather of the season to southern Manitoba with temperatures in the minus teens and lows in the minus 20s by the end of the week.. a shocking change from the unusually mild weather we have been experiencing since late October (today will mark Winnipeg's 44th consecutive day above normal since the warm weather streak started Oct 21st). But first we'll have to deal with a minor system passing through southern Manitoba Saturday night into Sunday morning that will bring a couple cm of snow along the way. That will clear out by afternoon with a pleasant end to the weekend as temperatures remain well above normal for early December with highs around the freezing mark (normal highs are now -7C with lows of -16C!)
NAM model valid 3 am Tuesday morning shows potential storm
system over southern Manitoba with widespread snow
causing significant impact to the Tuesday morning commute
Stormy Tuesday?  Things start to get interesting Monday night into Tuesday as a storm system over Montana tracks towards the Red River valley, possibly bringing significant snowfall across southern Manitoba, including Winnipeg. Most models are suggesting that southern Manitoba could be seeing 10-20 cm of snow with this system as well as increasing northwest winds and falling temperatures on the backside of the storm Tuesday. One model however, the Canadian GDPS, is suggesting that the storm will mainly miss southern Manitoba before clipping southeast Manitoba Tuesday night into Wednesday. This solution could easily change over the next few days, so keep up to date on this potential storm system for southern MB that could have significant travel impacts Monday night into Tuesday. Regardless of what happens, be prepared for a big change to significantly colder weather by the middle of next week!     

Friday, December 02, 2016

A November to remember - warmest November on record in Winnipeg and much of Manitoba

November 2016 will go down as the warmest November in 144 years of records in Winnipeg as a mild pattern that began at the end of October persisted right through the month. In Winnipeg, November ended up with an average monthly temperature of +3.1C, a whopping 8C above the monthly normal of -4.9C, easily beating the previous all time warmest Novembers of 1899 and 1923 at +1.3C. (Records for Winnipeg date back to 1872). Every day of the month was above normal, with an exceptionally mild first half that saw temperatures soar to a record high of 18.8C on Nov 9th.  The main story in November was the notable lack of cold, with only 5 days of the month seeing temperatures of -5C or colder, the fewest such days on record for a November (previous lowest was 7 days in Nov 1899)  Normally, November sees 20 days of -5C or lower, with an average low of -15C by Nov 30th!  The average low during Nov 2016 was an incredible -1.0C, which is just about the normal average HIGH for November (-0.6C)  The lack of cold weather resulted in a delayed start to winter, with the first measurable snow of the season falling on Nov 22nd.. the latest first measurable snow on record in Winnipeg (previous latest was Nov 21 1963)       

Mean monthly temperatures for November in Winnipeg 1872-2016
November 2016 was by far warmest in 144 year record 

Monthly temperature graph Nov 2016
Every day was above normal

Temperature anomaly map for Nov 2016 shows
core of anomalous warmth was over Manitoba

The list of records set in November in Winnipeg is impressive.  Among the notable milestones..
  • warmest November mean temperature (+3.1C, normal -4.9C)
  • warmest November mean daily maximum (+7.2C, normal -0.6C)
  • warmest November mean daily minimum  (-1.0C, normal -9.2C)  
  • most humid November (average dewpoint +0.3C, first time Nov avg over 0C)
  • 2 daily record high maximums (18.8C on Nov 9th, 13.6C on Nov 12th)
  • 3 record warm daily minimums (7.4 Nov 6, 4.8 Nov 9, 0.1 Nov 24
  • least number of days at or below -5C in Nov  (5 - previous low 7 in 1899)
  • least number of days below 0C in Nov (18 - previous low 20 in 2015)
  • latest date of first measurable snowfall of the season (Nov 22nd)  

The record warm November helped give Winnipeg its second warmest climatological fall on record (Sep 1 - Nov 30) with an average temperature of +8.0C, second only to 1963 (+8.6C) 

Average fall temperatures - Winnipeg (1872 - 2016)
graph credit @jjcwpg 
As of December 2nd, the mild weather pattern was persisting over southern Manitoba, with Winnipeg on its 43rd consecutive day above normal (a streak that started Oct 21st)  However, long range outlooks call for a pattern change to colder weather by the middle of next week.. putting an end to incredible 6 1/2 week run of above normal temperatures across southern MB.    

Tuesday, November 29, 2016

Finally looking like winter..

The storm system that brought a mix of snow and rain to much of the Red River valley Monday is now slowly tracking into Minnesota this morning, with colder air and snow wrapping around the system across southern Manitoba. Rain overnight changed to snow early this morning in Winnipeg, and will continue through the day with 4 to 8 cm possible by evening. Temperatures will hold steady near the freezing mark all day with northerly winds gusting to 50 km/h. Road conditions will once again be challenging, especially this morning.. so expect another SLOW commute today and give yourself plenty of time to reach your destination. Periods of snow will continue tonight with another 2 or 3 cm possible before snow tapers to flurries Wednesday.  Temperatures will gradually be cooling off over the next several days with highs below freezing.. so it looks like the covering of snow we get today into tomorrow will finally be sticking around for the winter. After the warmest November on record, it looks like winter is finally here!    

Tuesday, November 22, 2016

Late start to winter - Winnipeg posts latest date on record for first measurable snow of the season

After a record warm start to November, winter finally returned to southern Manitoba as the first measurable snow of the 2016-17 winter season fell across Winnipeg and southeast Manitoba today. Snow, mixed with ice pellets, began overnight creating a slippery and slow morning commute. About 3-5 cm of snow fell across the city by midday before it turned to a misty drizzle.  The snowfall marked the latest date on record for the first MEASURABLE snowfall of the season ("measurable" snowfall is defined as a snowfall of 0.2 cm or more)  The previous latest date of the first snowfall in Winnipeg was Nov 21 1963, set during the warmest fall on record (sidenote: President Kennedy was assassinated the next day in Dallas). Winnipeg snowfall records date back to 1872 (144 years of data)

Today's snowfall also marked the first time in 225 days that Winnipeg has had measurable snow (last recorded on April 10th when 0.4 cm fell). The 225 days is Winnipeg's 3rd longest snowless streak on record, behind only 1998 (232 days) and 1900 (228 days)  Average snowfree period in Winnipeg is 181 days, which means Winnipeg enjoyed 6 more weeks of snowfree weather this year compared to average.

Saturday, November 19, 2016

Major winter storm bypasses Manitoba.. Winnipeg still waiting for first measurable snow. Next threat for snow Monday night into Tuesday

The first major winter storm of the season blasted
Minnesota and NW Ontario Friday with
blizzard like conditions, but spared Manitoba
(photo along I-94 in Minnesota)
A Colorado low winter storm system tracked across Iowa into southern Minnesota Friday bringing a blast of wintery weather across much of northern and western Minnesota. The storm dropped 20-40 cm of snow across northern Minnesota with up to 60 cm (24 inches) reported near Orr in the far north. The storm also produced strong northerly winds which resulted in blizzard like conditions across much of the western state leading to numerous traffic accidents and some road closures. As the storm moved north, heavy snow pushed into NW Ontario mainly east of Dryden with 30-40 cm reported in Atikokan and Upsala, and 10-25 cm in Thunder Bay. Earlier in the week, models were suggesting this storm could be taking aim at southern Manitoba, but the storm took a track further south and east sparing Manitoba from any major impact. We did however get colder weather on the backside of the storm with northerly winds producing bands of lake effect flurries off Lakes Winnipeg and Manitoba. After a record mild start to November with well above normal temperatures over the first half of the month, temperatures will be closer to normal over the next few days.

When's it going to snow here? 

So after missing this big storm Friday, and missing several snowfalls in October which affected Saskatchewan and Alberta, Winnipeg and much of the RRV are still awaiting their first measurable snowfall of the season. As of today (Nov 18th), Winnipeg has gone 222 straight days without measurable snow, the 4th longest such streak on record here (see table below). Our last measurable snow in the spring was 0.4 cm on April 10th (we had some snowflurries on May 13th, as well as Oct 7th and Nov 2nd, but no measurable accumulation on those days, just a "trace")    

Top snowless streaks in Winnipeg as of Nov 15
records since 1872 (chart courtesy of @jjcwpg)

Next threat for widespread snow across southern MB
will be overnight Monday into Tuesday 

(NAM model valid 6 am Tue morning Nov 22) 

Barring any measurable snow from lake effect flurries tonight into Saturday morning (some areas east and west of Winnipeg are getting some accumulating snow off Lakes Winnipeg and Manitoba), the next threat of snow over southern MB will be Monday night into Tuesday as a low pressure system in Saskatchewan moves east, spreading an area of snow into Manitoba. This will not be a major winter storm like the one that hit Minnesota today, but it may result in our first measurable snow here in Winnipeg and the RRV, with perhaps 2-5 cm by the Tuesday morning commute.