Pleasant Weekend Ahead…Enjoy It!

Winnipeg, along with the rest of Southern Manitoba, will enjoy a very pleasant weekend with temperatures climbing above 0°C over the next few days before a cold front sweeps through Southern Manitoba on Monday morning.

Foggy Winnipeg

A foggy morning in Winnipeg; submitted by JJ.

Winnipeg and the Red River Valley will enjoy a beautiful weekend with most cloud clearing out by this afternoon. Daytime highs will continue to climb over the next three days, with highs climbing to near 1 to 2°C today and Saturday, and getting up to nearly 4°C on Sunday.

Our warm temperatures, combined with light winds forecast for tonight means that fog will likely redevelop through many areas in the RRV; if it makes a return tonight, it will be the fourth night in a row with fog in Winnipeg and surrounding areas. Winds are forecast to increase through the night on Saturday night to 10-15km/h which should be enough to prevent fog from forming again.

Sunday Morning Prognosis

Analysis of the 72h prognosis from the GEM-Global, valid 12Z Sunday morning. Warm fronts and cold fronts are represented by red and blue lines, respectively.

The next change in the weather will be coming on Monday morning to Southern Manitoba. Through the weekend, a powerful low pressure system will track through the NWT into the Kivalliq region of Nunavut. This system will shift the large-scale pattern over the center of the continent and will allow arctic air that has been trapped unusually far north over the past couple weeks to spill southwards across the Eastern Prairies. The cold front will sweep across Manitoba on Sunday and push through Winnipeg by Monday morning.

This will bring brisk northerly winds to us for Monday and temperatures that gradually fall through the day. Currently it looks like we could see temperatures as low as -26°C on monday night into tuesday morning. Very little moisture is associated with this system, and current indications are that there will be very little or no snow with the passage of the cold front. Temperatures will be a little below normal on Tuesday and Wednesday, with daytime highs a little below -10°C.

A Pleasant Week

Now that we’ve gotten our uncertain snow systems out of the way, Winnipeg will enjoy a pleasant rest of the week with mild temperatures and increasingly sunny skies.

500mb Winds & Heights

500mb Heights & Winds valid 12Z Thursday morning, Februrary 2nd, 2012.

As this week progresses, we’ll see a zonal upper flow begin to amplify slowly as upper-level ridging builds into the Prairies. This will result in a fairly simple forecast:

  • We should expect daytime highs close to freezing, moving towards slightly above freezing (2 or 3°C) by the weekend, with overnight lows between -10°C and -5°C.
  • We’ll have just a very slight chance of flurries this morning and Thursday morning as a couple weak troughs pass through the Red River Valley associated with some weak shortwaves that are embedded in the amplifying upper level flow.
  • We should see the sun poke out in a mix of sun and clouds this afternoon, and then see clearing skies overnight. We should then see mostly sunny skies for the rest of the week!

The long-term forecast looks pretty quiet, with most major systems keeping well south of Manitoba and upper ridging dominating our weather pattern. Long-range models hint at a high over low block setting up over the Northwestern United States in the 7-10 day range, which would allow colder arctic air to spill southwards over Saskatchewan and Manitoba; but that’s a long ways off and could all change! For the rest of this week, we’ll be enjoying above-normal temperatures and finish the week with plenty of sunshine.

And for those who are curious, Rob has written up a good summary of this past January’s temperatures on his blog. This January was the 3rd warmest January on record, coming in behind the January 1944 and January 2006. This comes right after the 9th mildest December on record, and pushes our streak of months with above normal temperatures to 7 consecutive months!

Another Warm (but Snowy?) Week

Southern Manitoba’s non-winter just keeps rolling along. Our record warm January will end just as it started – unusually mild. Although there may be an unwelcome surprise to end the month as well…

GEM Temperature forecast - Tuesday, January 31, 2012

GEM Temperature Forecast – Tuesday, January 31, 2012

The last few days of January are expected to feature high temperatures near zero degrees. Monday and Tuesday should be near to or slightly above zero in much of Southern Manitoba. Wednesday is not in January, but it is also expected to be quite warm with highs close to zero.

Surface Pressure Map - Tuesday, January 31, 2012

Surface Pressure Map – Tuesday, January 31, 2012

This warm weather may come at a cost though. During the late hours of Sunday night and early hours of Monday morning snow was falling in many parts of Southern Manitoba. Overnight accumulations were generally light, mainly 2 to 4cm or less. However, the bigger concern for snow will come Monday night and Tuesday. An Alberta Clipper type system is forecast to emerge from the Rockies on Monday. This system will then quickly dive southward on Monday night. Currently the potential for snow with this system is very uncertain. Weather models are predicting anywhere from 0cm to 15cm. As a result, it is very tricky to pin down a more precise snowfall range at this time. As a rough guideline, I will suggest that most parts of Southern Manitoba will see 3 to 6cm of snow with this system. However, bear in mind that we have low confidence in this forecast. The map above shows the expected location of the low pressure system on Tuesday morning (6am). As the exact track and intensity of this system becomes clearer we will provide further updates.

Climate Prediction Center Outlook

Climate Prediction Center Outlook – February 4-8

On a different note, long range modelling shows warm weather persisting through the first 7-10 days of February. The Climate Prediction Centre outlook, seen above, indicates that much of the United States and Southern Canada will be warmer than normal to begin the next month. Many people have been asking where winter has gone…your guess is as good as mine.

Elsewhere in Weather News

Iggy Thrashes Indonesia, Spawns Tornadoes

Tropical Cyclone Iggy has spawned over the eastern Indian Ocean and has brought with it powerful thunderstorms and tornadoes. As the rain season is peaking in Indonesia, chances of a tropical storm increase greatly and could potentially bring with it powerful tornadoes affecting the region.

Infrared Satellite image of Indonesia

Iggy bringing storms to Indonesia on January 26th. IR – cloud tops satellite picture. (Source: NASA and Earthsky).

In total, 22 Indonesian districts experienced damage from the tornadoes, several with significant devastation including Java and Bali, the hardest hit areas. Unfortunately, the tornadoes damaged more than a thousand houses, killed as many as seven people and injured fifty more as it knocked down trees and overturned boats by the shoreline.

Iggy is forecast to move to the south-east, sliding by Australia’s western coast and bringing with it heavy rains, strong winds and possibly more tornadoes. As very warm waters lie to its south-east, Iggy will also strengthen as it moves towards Australia, with the possibility of the cyclone reaching category 2 (winds of 150k/h near the core) by the time it’s all said and done.

Strong Cold Front Pushes through Dixie Alley, US

As the southern states continue to get beat down, yet another powerful system has pushed through the Dixie Alley bringing with it… yes you guessed right, more tornadic supercells! Most of the tornadoes were concentrated in the Mississippi, Arkansas and Alabama regions; where on the evening of January 22nd, optimal conditions were in place for long-tracked supercells. In total, about 30 tornadoes and more than 150 cases of high wind gusts were reported during this unusually strong system that spanned from Chicago to the Gulf of Mexico. The system then moved on to Georgia where a couple tornadoes were again reported from the same system the next morning.

RADAR image of severe storms in the Southern US

Time lapse (Sun, Jan. 22, 7pm thru 7am) RADAR imagery where rotation was detected. (Source SPC, G. Carbin)

The region finally caught a break from the parade of storm systems passing through this past weekend with a ridge of high pressure that built itself behind the front. Calm weather in the region is expected to last at least until Wednesday evening, where there is another system on the horizon.

Elsewhere in Weather News has been provided by Matt