IR Satellite Image of Late-March Storm over the Southern Prairies

Winter Storm Slams Manitoba

A potent spring storm is moving into Manitoba today and will likely exit the region known as one of the strongest of the Winter 2014/15 season. This storm has already brought drizzle, rain and freezing rain to southwestern Manitoba & the Red River Valley and will end up delivering the whole wintery mix by the time all is said and done. Environment Canada has issued a swath of heavy snowfall warnings and special weather statements across Manitoba in advance of this system.

Tuesday Night

Tuesday Night
-1°C
Rain changing to snow

Rain will redevelop this evening and persist through much of the overnight period until a cold front pushes through the Red River Valley and switches the precipitation over to snow. Many areas in the Red River Valley will see around 5-10mm of rain. Alongside the switchover to snow, strong northwesterly winds to 40-50km/h with gusts as high as 70km/h will begin to move into the Red River Valley. The combination of falling snow and strong winds, coupled with the temperature dropping below zero overnight after a day of melting, drizzle & rain will likely produce very poor driving conditions with slippery roads & poor visibilities in blowing snow by Wednesday morning.

Wednesday

Wednesday
⇒ -2°C / -11°C
Snow ending in the afternoon; windy

Snow will continue through Wednesday morning before beginning to taper off through the afternoon with a further 5-10cm possible for the City of Winnipeg and the Red River Valley. As mentioned before, the snow will be accompanied by strong northwesterly winds to 40-50km/h which will produce a fair amount of blowing snow as well. Temperatures will drop just barely to -2 or -3°C through the day. Given the relatively mild temperatures, it’s quite likely that as soon as the snow begins to taper off, the blowing snow will too; falling snow will be needed to produce it and it’s unlikely we’ll see much ground-based blowing snow after the fact. Winds will begin to taper off late in the afternoon or in the early evening as the storm moves off into Ontario. Left behind the storm will be partly cloudy skies as temperatures drop to around -11°C.


Storm Update

As expected, many regions across Manitoba saw a significant dump of snow overnight and into this morning. Snowfall totals to 10:30AM CDT across Manitoba are:

Location Snowfall Amount
Winnipeg 5cm
Portage la Prairie 5-10cm
Brandon 6cm
Steinbach 5cm
Dauphin 15-25cm
Rossburn 20cm
McCreary 18cm
Neepawa 15cm
Fisher Branch 15cm
Roblin 14cm
Elkhorn 10cm
Argyle 10cm
Swan River 8cm
Miami 6cm
Morris 2cm

In addition to the heavy snow, many areas through the Red River Valley saw several hours of rain last night. Here in Winnipeg, around 8mm fell overnight, and preliminary reports indicate that similar amounts were seen through much of the Red River Valley. In addition to the snow and rain, very strong winds to 50-60km/h moved into Red River Valley this morning producing blowing snow and helping make sure roads are slick.

The winter weather has wreaked havoc on area infrastructure with numerous accidents on highways as well as complications to power infrastructure with numerous pole fires & power line damage events reported. Many motor-vehicle collisions were reported on Manitoba Highways, with several resulting in sections of Highways 1 and 75 being closed. Two of the more significant ones, pictured above, involved a jackknifed semi-truck collision near Elie and a school bus rollover near Ste. Agathe on Highway 75.

Conditions have begun to improve in the Red River Valley; winds remain strong however with the snow finally moving off into Ontario, much of the blowing snow has stopped. Road conditions will continue to be poor through the remainder of the day, so if you are driving, especially on area highways, be sure to give yourself extra time and be cautious.


Thursday

Thursday
-6°C / -11°C
Partly cloudy

Thursday will be a mainly sunny day – perhaps just a few lingering clouds – with a cool high of just -6°C. Winds will be light, so with the increasingly strong March sun it may not actually feel all that bad outside. Even with the sub-zero temperatures, expect plenty of melting to happen. We head into Thursday night with clear skies and cool off to around -10 or -11°C again overnight, although that could be a couple degrees warmer depending on when cloud cover arrives from…

Friday

Friday
-3°C / -8°C
Mainly cloudy with a chance of light snow

Friday will bring mainly cloudy skies as clouds push in either early Friday morning or late overnight on Thursday thanks to a system rippling through Southern Manitoba from the northwest. It will most likely produce a band of snow through portions of the Parkland, Southwest and into the Western Red River Valley. Under this band, accumulations of 1-2cm look possible at this time. There’s a little uncertainty as to the exact track, given that it’s 3.5 days out at this point, so it may end up a little further west or east. With the current “most likely” track, Winnipeg sees a fairly decent chance at some flurries but little in the way of accumulations. Temperatures will climb to around -3°C with fairly light winds. Friday night looks pleasant with light winds again and a low near -8°C.

Long Range

It’s looking as if another storm is possible on Saturday night as a shortwave tracks across Manitoba.

GDPS 24hr. QPF Forecast valid 12Z Sunday March 29, 2015
The GDPS is forecasting a fair amount of precipitation associated with a significant storm moving through Manitoba this weekend.

Fortunately, it seems like it will be bringing enough warm air with it that precipitation would fall as rain. Either way, though, it looks like we’ll see plenty of cloud and wind this weekend. After a long spell of little in the way of weather, it looks like a typical, more active springtime pattern is setting up!

Strong Winds Blast Southern Manitoba

Strong winds will blast across Southern Manitoba today as a very powerful low pressure system crosses Northern Manitoba. The winds will also usher in an unseasonably cool air mass that will give us a very chilly night before the upper ridge begins to rebound into our region.

850mb Temperatures for Thursday morning from the GEM-REG

850mb temperatures for Thursday morning from the GEM-REG. A cold trough of 850mb temperatures between 0-1°C will rest over the Red River Valley and Whiteshell, contributing to unseasonably cold overnight lows.

A powerful low pressure system with a central pressure of approximately 984mb is pushing across Northern Manitoba and will bring a very strong pressure gradient across the Red River Valley today that will usher in 50-60km/h winds with gusts as high as 80km/h. This system has a history of producing very strong winds; on Monday it brought widespread winds in excess of 100km/h to Southern Alberta and yesterday it brought winds between 80-110km/h through Saskatchewan and Northern Manitoba.

The winds will pick up in the Red River Valley this morning and we’ll see several hours of fairly strong westerly winds. Unlike regions to our west that had to deal with the winds for a fairly prolonged period of time, the winds will move through the region fairly quickly as the low accelerates out of Northern Manitoba into Hudson Bay. As a result, winds should let up noticeably by the evening.

In behind this system, fairly cold air will sweep across the province. Across the Red River Valley, overnight lows will be kept a little warmer by some light winds expected to continue through the night. Through the Red River Valley, overnight lows will generally drop to 3-5°C tonight, however if any areas see the wind let up, it would certainly be possible to see overnight lows dip to 1-2°C under clear skies and calm winds. The most likely area for this to happen, though, is a little further east in the Whiteshell where the trees will help protect the surface from light synoptic winds.

Temperatures will return to seasonal on Thursday as an upper ridge begins to build eastwards across the Prairies. We’ll see a mix of sun and cloud across the Red River Valley with a very slight chance of a shower as warmer air begins to push into the region. Daytime highs should be near 19-20°C on Thursday with overnight lows on Thursday night once again rather chilly in the 4-6°C.

Warm air moves back in for the weekend, with plenty of sunshine and highs near 25°C on Friday and Saturday. Things look to cool off a bit on Sunday as another cold front passes through.

Showers and Thunderstorms, U2, Then More Rain

While the temperatures may not be completely summer-like, today will be a day that indicates a clear shift towards summer weather.  An incoming disturbance will produce widespread convection today with showers and thundershowers covering much of Southern Manitoba.  Pleasant weather should make an appearance for tomorrow’s U2 concert, but Winnipeg will quickly return to rainy weather on Monday as a system that will bring significant challenges to those with housing near the lake moves into the province.

A substantial stacked low pressure system currently positioned just east of Regina is set to move across Southern Manitoba today.  A few factors will combine to produce what could be a fairly interesting afternoon today.  

First, a southerly wind, combined with yesterday’s rain has pushed dewpoints to nearly 10°C throughout the Red River Valley with a relatively deep layer of evidenced by the stratus cloud that has managed to form overnight despite winds of 15-20km/h.  This moisture will provide the fuel needed for thundershowers. 

Secondly, rather cool mid-level temperatures will be in place.  As the low pushes in, temperatures in the mid-levels should drop to -7 to -8°C, which when combined with daytime heating will produce ample instability to get convection initiating.  It is also indicative of fairly low freezing level, which will help in the generation of small hail.

And last but by far not least, the fact that this upper disturbance is stacked on top of a surface low means that there will be significant rotation through the mid and upper levels which will help storms develop rotation.

When these things combine, it’s considered a pretty classic case for cold core funnels.  These funnel clouds do not develop in the classic sense; instead of developing in the rapidly rotating updraft of supercell thunderstorms, they develop through the descent of cold air through a storm that has developed rotation due to significant mid-to-high level spin.  Think of it as a funnel cloud that develops because of how air is coming out of the cloud rather than how air is being ingested into the cloud.

These funnel clouds do have the potential to touch down and become tornadoes.  If they do, they are often extremely short lived (< 1-2 minutes) and are much weaker than the tornadoes that form from supercell thunderstorms.  Any of the storms that could produce a cold core funnel cloud are also extremely likely to be capable of producing hail.

I think that most areas across Southern Manitoba could see hail today, although the threat is biggest in the Red River Valley and east.  Winnipeg and areas south should most likely see pea-sized hail should it develop.  Further east in the Whiteshell and Sprague regions, the potential exists for marginally severe hail (about dime to quarter-sized).

The biggest hindrance to the development of all this is the lack of focus for convection.  With no strong front or trough, convection may simply blow up all over the place instead of in any organized fashion, which will leave all the storms fighting each other for resources.  If this happens, it’s likely that it would quickly blossom into a big area of showers with only the odd lightning strike.

My bet for the Red River Valley is this: low stratus this morning will burn off quickly with the morning sun.  By mid-morning, most areas should be seeing a mix of sun and cloud.  Daytime heating, combined with a weak cap, will initiate the convection earlier than typical, resulting in showers spreading into the Red River Valley around 12-1PM or shortly thereafter.  Any showers that develop in the RRV are just as likely to become thundershowers, and I think there will be numerous funnel clouds today.

As for Sunday and the big U2 concert, it should be quite a pleasant day.  We’ll see a sunny morning give way to a mix of sun and clouds in the afternoon with a daytime highs around 15-17°C.  It will cool off quick in the evening, so make sure to bring a sweater if you’re headed to the concert.


12hr. QPF valid 06Z May 31 from the 06Z May 28 GFS

After that, it looks like a significant low pressure system will track through Southern Manitoba, bringing nothing but headaches and grief for residents on the lakes.  Current indications are for a widespread area receiving 20-40mm of rain with winds potentially as high as 50 gusting to 70 km/h.  This system will do no good for the flood-striken areas near the lakes, and I would suggest that residents in the area should begin to make preparations already as with the strong winds out of the north-east, significant water damming will likely occur on the western to southern beaches.

Miserable Weather on Tap

Don’t let the bits of sun and relatively warm temperatures fool you; tonight is going to be downright awful.

A complex double-barreled low pressure system (a term used when two separate lows are moving together as one entity) is moving out of Saskatchewan and Montana into Southern Manitoba this morning.  This system has brought a mix of precipitation into Southern Manitoba this morning, including freezing rain over western areas and heavy snow in the Interlake.  Numerous warnings have been issued across the region for weather happening now or expected to happen this evening.

The risk of freezing rain will persist through much of Southern Manitoba for an hour or two longer before temperatures will be warm enough that any precipitation will simply fall as rain.  Even though little precipitation has fallen over the Red River Valley this morning, Manitoba Highways is reporting that many sections of Highway 75 and Highway 1 heading west of Winnipeg are partly iced cover due to the slight melt and re-freeze yesterday afternoon.  As temperatures will just barely get over 0°C today, there may be portions of highways that are still quite slippery throughout the day.

Tonight
Perhaps the biggest impact from this storm will occur tonight over the Red River Valley.  As the low passes to the east, cold air will plummet down the backside of the system through the RRV.

 
24hr Accumulated QPF valid 12Z Saturday March 12, from the 00Z run of the GEM-LAM REG Model 

As the system passes, an intense band of wrap-around precipitation will move into the RRV, bringing heavy snow to Winnipeg by 6 or 7PM tonight.  Along with this heavy snow, this system will bring significant winds as well.


Surface Winds valid 06Z Saturday March 12, from the 06Z run of the GEM-LAM REG Model 

Sustained winds of 50-60 km/h with gusts potentially as high as 90 km/h will blast cold air into the RRV, which will plummet the temperature from 0°C or +1°C down to approximately -14°C or -15°C over the span of a few hours.  This will rapidly freeze any standing water which will very likely create extremely slick roads tonight.  And last but not least, these winds, combined with the heavy snow, will very likely produce blizzard conditions through a good portion of the night.

The weather conditions will deteriorate extremely quickly this evening to become a significant winter storm.  Anyone who has plans to travel in the Red River Valley tonight should keep updated on warnings, forecasts (or for a smartphone), the RADAR, and highway conditions to be able to make safe, educated travel plans.  Good satellite imagery to track this system can be found here at the U of M.