Cool Weather Breaks Records

Temperatures will remain well below normal this week in the wake of Monday’s snowstorm. Far from the 45cm of snow that fell in Bismark, only 5-10cm fell across Southern Manitoba while strong northerly winds coupled with near-0°C temperatures to spare no expense in turning highways into sheets of slush and ice. Unfortunately it looks like the cool weather reinforced by this system isn’t going anywhere anytime soon.

Snowfall Totals from Monday’s Storm

City Snowfall (cm)
Winnipeg 7.8
Oakbank 8.6
St. Alphonse 8.4
Miami 10.0
Winkler 12.0

Record Cool

As mentioned above, the cool weather is here for a while yet. A stable atmospheric structure called a high over low (or Rex) block has developed off the west coast of North America. This feature will produce persistant ridging over the Eastern Pacific which will in turn produce relatively persisitant troughing over western North America. This persistant troughing will tend to keep the storm track to our south and any warmer air shunted off towards the eastern half of the continent. The feature is expected to weaken towards the end of the week, but not enough to truly break down the rather stationary pattern. While troughs will weaken periodically over the next week, the general trend will be to reinforce and redevelop them instead of bringing any significant ridging onshore.

NAEFS 8-14 Day Temperature Outlook issued April 17, 2013 at 00Z

NAEFS 8-14 Day Temperature Outlook issued April 17, 2013 at 00Z.

The above image is the 8-14 Day Temperature Anomoly outlook from the NAEFS1; it’s an “at a glance” product that tells you whether the models think that it will warmer or cooler than normal next week2. As you can plainly see, a wide swath of cooler than normal temperatures is expected over much of the center of the continent.

Unfortunately, this is compounding on an already exceptionally long winter. Rob, over at Rob’s Blog, put together a plethora of interesting statistics about this spring:

[…] Today was the 36th consecutive day below normal in Winnipeg (March 9th was the last day above normal) and it appears that below-normal tmeperatures will continue into next week. […] With no prospect for +5°C the rest of the week, this year will mark the latest date in 141 years that Winnipeg has reached it’s first +5°C of the year (record back to 1872). The previous record latest date was April 15th 1950 (the year of the historic Red River flood).

Rob’s Blog

Rob rubs salt in the wounds a little more by reminding us that on average Winnipeg sees at least 15 days with highs above 5°C and sees on average at least 10 days with highs above 10°C. It’s an excellent read on the stats for this spring and I recommend you go check it out.

Long-range models continue to pepper us with hope in the long, long range. There is growing consensus on a pattern break-down by the end of the month with temperatures beginning to warm in earnest through the start of May. That could just be the fact this cold air can only fight against the increasingly strong sun for so long.

This Week

Wednesday

2°C / -9°C
Cloudy; gradual clearing.
Thursday

2°C / -8°C
Mainly sunny.
Friday

2°C / -8°C
Sunny.

The weather through the rest of this week will be uneventful. The main storm track will remain well to our south, bringing severe thunderstorms to portions of the Southern Plains and more snow to the Dakotas. We’ll see cloudy skies today as overruning cloud pushes into Southern Manitoba from the system psuhing through the Dakotas with some flurry activity over Southern Manitoba. For the most part, the snow should stay out of Winnipeg while skies gradually clear through the evening and overnight period and we’ll be left with mainly sunny skies for Thursday and Friday as another Arctic ridge pushes into the Prairies. Daytime highs will remain steady near 2°C and overnight lows will be near -8 or -9°C.

Looking towards the weekend, it looks like we’ll see more of the same temperature-wise, and a chance for some light snow as a weak low pressure system moves across the Prairies. At this point it does not look like this system will bring any significant accumulations with it.


  1. North American Ensemble Forecast System 
  2. A Day 1-7 outlook would be for the coming week, Days 8-14 would be the week after. 

The Calm After the Storm

After a stormy start to the week over the entire Red River Valley, conditions will begin to settle down.

image

The low will move off into Ontario Today

Monday

Monday
image
Snow ending
-1°C / -6°C

The snow will gradually taper off over Southern Manitoba today, with many places seeing close to 5cm in total. Wind speeds will remain high, with values of 30 to 40km/h gusting up to 50-60km/h from the north. Temperatures today will be around or just below zero in Southern Manitoba, but of course the wind will make it feel a bit cooler than that.

Tuesday and Wednesday

Tuesday
image
Chance of Flurries
-1°C / -7°C
Wednesday
image
Chance of Flurries
1°C / -8°C

Tuesday will be a benign day weather-wise, with high temperatures generally just below zero in Southern Manitoba. The wind will be relatively light and from the north, making for a fairly comfortable day.

Wednesday will be a bit warmer than Tuesday, but otherwise there won’t be an significant changes in conditions. The wind will again be light and from the north, with only a slight chance of flurries.

Long Range

The long range forecast is beginning to show some glimmers of hope. Models are beginning to show signs of a pattern change towards normal or just above normal conditions as we move towards the end of April. Unfortunately, that means we’re likely stuck with well below normal weather at least through this week…but hopefully that will change in the not too distant future.

Winter Storm on the Way; Spring Still M.I.A.

Yet more winter weather is in store for Winnipeg as we remain stuck on the cold side of the jet stream while the main storm track through the Northern Plains of the United States becomes more active. While weather will remain relatively benign through today and tomorrow, things will become more active on Sunday and persist through much of next week.

Friday and Saturday

Friday

2°C / -9°C
Chance of scattered flurries this morning. Becoming a mix of sun and cloud.

We’ll see the chance of some scattered flurries through the Red River Valley this morning as a weak trough hangs back into Southern Manitoba from the low pressure system walloping Southern Ontario. Any snow that falls will be light and non-accumulating. Through the day the skies will break up a bit and we’ll end up under a mix of sun and clouds with a high near 2°C here in the city and closer to -1 or 0°C elsewhere in the Red River Valley. Tonight we’ll see partly cloud skies with temperatures dropping to around -8 or -9°.

Saturday

4°C / -7°C
Mostly sunny.

On Saturday, we’ll see fairly sunny skies with the warmest temperatures we’ve seen in a while1 as our daytime high rockets all the way to a balmy 3 or 4°C! Winds will remain relatively light out of the northeast throughout the day. Clouds will begin to move in through the overnight period in advance of the next weather system as we drop to around -7 or -8°C.

Sunday into Monday

Sunday

3°C / -4°C
Cloudy. Slight chance of showers or flurries in the afternoon. Snow beginning overnight.

Here comes winter. A major storm system will push out of Wyoming through South Dakota on Saturday night and into central North Dakota through the day on Sunday. Convection will fire up to the east of the low which will supply moisture that will wrap northwards and westwards through an area of strong lift on the north side of the low. This area of precipitation will push northwards through N. Dakota into Southern Manitoba pushing northwards to Winnipeg by Sunday evening. Light snow will begin overnight as winds strengthen out of the north.

GDPS 12hr. precipitation forecast with surface pressure.

GDPS 12hr. precipitation forecast with surface pressure.

By Monday morning the low pressure system is forecast to be near Lake-of-the-Woods with a strong pressure gradient situated over the Red River Valley. Snow will be wrapping around the back side of this system into the valley while strong northerly winds of 40-50km/h help blow it around. Temperatures will, fortunately, be near the freezing mark, but with the strong winds and damp air it will feel quite cool.

The system should leave the region overnight Monday with a cool, benign weather pattern settling in once again.


  1. It’s rather depressing that +3°C can possibly be the warmest temperatures we’ve had in a while when it’s mid-April. 

Sunny Week Ahead; Potentially Stormy End To The Weekend

The remainder of this week will be filled with sun as yet another Arctic ridge dominates over the Eastern Prairies, continuing the unshakable grasp of winter. While temperatures will be milder compared to the first half of the week, we’ll reamain well below our normal of around +9°C but with the milder temperatures the sun should be able to continue slowly melting the snow we have. Unfortunately, it’s looking like a fairly significant storm may bring another shot of winter.

This Week

Wednesday

0°C / -14°C
Sunny
Thursday

2°C / -10°C
Sunny
Friday

4°C / -8°C
Mainly sunny; increasing cloudiness in the evening.

A significant Arctic high pressure system will lay dominant over the Eastern Prairies over the next few days with the main ridge axis running from near Churchill towards southwestern Manitoba. We’ll see temperatures slowly climb over the next few days, but our daytime highs will likely remain in the 0-4°C range, although any areas in the city that have managed to become mostly snow-free may get a little warmer than that. Regions outside the City of Winnipeg will likely top out within that range. Perhaps most significantly will be the warming of our overnight lows, which will be in the low minus teens this mronign and move into the minus single digits by the end of the week.

We’ll have plenty of sunshine over the next few days with some clouds starting to work their way into the Red River Valley on Friday night associated with a weakening system pushing through Saskatchewan.

The Weekend

GDPS 24 Hour Precipiation Accumulation valid Monday morning.

24hr. precipitation accumulation valid Monday morning from the GDPS. Current forecast shows the potential for up to 25mm of liquid equivalent precipitaiton.

Saturday looks to be a mix of sun and cloud, but Sunday will be quite an interesting day weather-wise as a Wyoming low pushes northeastwards into southern North Dakota through the day. While the morning looks to start off cloudy, the GDPS1 deepens the low significantly through the afternoon, spreading precipitation northwards into Southern Manitoba. There’s still plenty of time and uncertainty, but this system (at the moment) looks like it could end up producing as much as 15cm of snow. How much actually accumulates will vary highly, since temperatures are expected to be right near 0°C and non-snow-covered surfaces will likely melt much of the snow on contact for the first several hours of the event. There’s also the possibility enough warm air will wrap north of the system that some of the precipitation will fall as rain instead of snow. This system would impact us through Monday as well given the current model output. We’ll keep our eyes on the development of this system; stay tuned.


  1. Global Deterministic Prediction System