A low pressure system advecting plenty of moisture Poleward from the Mediterranean Sea was in place over south-central France on Monday making for a good setup of long lasting heavy rains. The rains, enhanced by scattered thunderstorms prompted Météo France to issue various warnings, from strong wind warnings to severe thunderstorm warnings in addition to the rainfall warnings. A few areas along France’s southern coast were particularly hard hit with rainfall totals between 180-210mm in six hours on Monday. In addition to that another general 40-50mm (some amounts higher locally) fell as the system was moving off on Tuesday. On Wednesday, another low pressure system quickly moved into the region, again bringing with it rain and more storms. There was also a report of a weak tornado accompanying the one of the storms.
With already saturated soils from earlier in the week, conditions were primed for overland flooding as the second system moved in. Helicopters and rescue workers were hard at work towards the end of this week as people got trapped in their vehicles and houses from the flooding in southeastern France. There were five deaths related to the flooding events and 6,000 households were without power. The damage from the unconfirmed tornado comprised of roofs blown off and trees uprooted.
Precipitation map (in millimeters) of the rainfall in Southern France on Monday only. (Source: Météo France)
Unfortunately the soggy weather is expected to stick around the region this weekend. The upper-level cutoff low located over Southern Spain will drift ever so slowly to the east but will bring with it more showers and rain to southern France.
In other news, a supercell hit Brisbane, Australia this past week and knocked out power to 90,000 residents. The storm brought just about everything with it; golf ball size hail, strong winds and flash flooding – damages are in the hundreds of millions.
Radar image at the time the supercell was passing over Brisbane. (Source: BoM)
A winter storm that is bringing all manner of treacherous weather to Alberta[1] will extend into Manitoba today and tomorrow in what could only be considered “a complicated setup.” Snow will arrive in multiple batches as weak upper-level impulses slide west-to-east across the province along a very strong mid-level warm front before the main low pressure system works its way into North Dakota spreading a final area of snow across Southern Manitoba alongside gusty northerly winds and colder temperatures. The whole system will push off into Ontario for Sunday leaving clear skies and cold weather to round out our weekend.
Friday
-11°C / ⇒ -11°C
Mainly cloudy with a chance of flurries; snow overnight
Saturday
⇓ -17°C / -22°C
Snow tapering off to a chance of flurries
Sunday
-19°C / -28°C
Clearing and cold
Environment Canada has issued snowfall warnings for the Parkland & Interlake regions.
While snow falls over Western Manitoba today, it will be a bit of a different story here in Winnipeg & the Red River Valley as some scattered morning flurry activity gives way to a fairly cloudy day with just a slight chance of some more scattered flurries. By late in the afternoon, however, more organized snow will begin building into the Red River Valley from the northwest, spreading southeastwards through the night.
This particular shot of snow will be courtesy of a very strong warm front in the mid-levels of the atmosphere that has been producing exceptionally snowy conditions in Alberta & Saskatchewan. Snow will continue through much of the night (a few breaks in the snow are possible) and into Saturday morning.
On Saturday, a strong cold front will push through the Red River Valley midday. This will lead to another distinct shot of snow associated with the cold front and the mixing zone behind it.[2] By the time all is said and done, around 5-10cm will likely have fallen here in Winnipeg and through much of the Red River Valley. If things really go off the rails, little could be seen as the first band of snow remains further north and the second band of snow passes to our south, but I don’t think that outcome is likely.
The “most probable” snowfall totals from the morning of Friday November 28th to the evening of Saturday November 29th, 2014.
The snowfall winners will be through Parkland Manitoba and the Interlake, where general amounts of 15-20cm are expected. Due to the terrain in the Parkland, up to a foot of snow could potentially fall in any areas prone to upslope enhancement.[3] The snow will taper off from northwest to southeast through Saturday afternoon.
Daytime highs today will range from around -10°C near the international border to -11°C here in Winnipeg to the mid-minus teens in the northern Interlake westwards into the Swan River region. Temperatures will remain fairly steady tonight through the Red River Valley, perhaps dropping a degree or two. Tomorrow will bring falling temperatures throughout the province as that cold front sweeps through; by the end of the afternoon temperatures will likely have dropped to around -17°C or so and then continue on an overnight low dropping into the -20 in range.
Sunday will bring clear and cold conditions to Winnipeg & Southern Manitoba. Highs will climb just above -20°C before dropping back down into the low -20s on Sunday night.
At one point yesterday, Environment Canada had issued winter storm warnings, heavy snowfall warnings, freezing drizzle advisories, and snow squall watches simultaneously for various parts of Alberta. ↩
It’s not uncommon to have what’s known as a “mixing zone” behind strong cold fronts in the winter time; the intense temperature contrast between the Arctic air and the air its replacing can result in as much as several hundred kilometers of low cloud and light-to-moderate snow in the wake of the front. ↩
…which essentially means anyone near the Riding Mountains or the escarpment. ↩
The coldest temperatures so far this season will be settling in for a short stay in Southern Manitoba before a powerful series of clippers move across the Prairies at the end of the week, bringing what may become one of the most potent winter storms seen so far this winter.
Wednesday
-18°C / -30°C
Mainly sunny
Thursday
-17°C / ⇑ -14°C
Increasing cloudiness
Friday
-10°C / -13°C
Chance of flurries
The deep freeze settles over Manitoba today as a potent high pressure system moves in from Northern Saskatchewan, bringing with it a fresh shot of Arctic air. Temperatures will warm to around -18°C from the mid-minus-twenties present this morning under mainly sunny skies. Tonight will bring the coldest temperatures of the season to Winnipeg and the Red River Valley with overnight lows dropping dangerously close – or even just below – the -30°C mark. Tonight’s record low for Winnipeg is -36.1°C set in 1891, so some solace can be had knowing it’s been colder.[1]
Tomorrow will see the cold air exit the region as a major system making landfall in British Columbia begins pushing warmer air eastwards across the Prairies. Temperatures will be on their way up, up, up with a daytime high near -17°C followed by a rising temperature trend overnight that brings temperatures up to around -14°C by Friday morning. While Thursday will start off clear, cloud will start spreading into the Red River Valley sometime midday or into the afternoon, with things becoming completely cloudy sometime in the evening.
Some light snow is possible on Thursday night along a mid-level trough in the region. While more consistent snow is likely over southwestern portions of the province, here in the Red River Valley little is expected in the way of accumulations. We’ll keep an eye on it, but it looks like amounts will remain less than 2cm in any activity that develops.
Friday Brings Winter Storm to Portions of Manitoba
Friday will likely be a bit of a mess of a day…somewhere. A potent low pressure system will track eastwards near the international border, spreading an area of snow ahead of it and another area of snow to its north. It’s really too early to make too many accurate predictions other than a whole host of weather being possible on Saturday. Some areas of the Red River Valley will likely see some snow while a more organized snow event occurs (once again) through Parkland Manitoba eastwards through the Interlake and into the Berens River Region. There’s simply too much uncertainty with the track and strength of the low at the moment to create a snowfall forecast; it looks like a possible snowfall warning event will occur through the Interlake[2] while lesser amounts track along and south of the Trans-Canada corridor. We’ll be making a snowfall forecast graphic a little closer to the event when we can have more confidence in the amounts.
Just one of many model solutions, the GDPS shows lighter precipitation amounts (just 2-5cm of snow, generally) in Southern Manitoba from Friday morning to Saturday morning.
On Friday evening, temperatures will continue to rise with southerly winds into the mid-minus single digits, but then the low will pass and the winds shift around to northwesterly at 30-40km/h. Ample low-level moisture coupled with an incoming – and very dry – 50kt jet at 700mb may result in some freezing drizzle or snow grains overnight. The northwesterly winds will bring in substantially colder air with temperatures dropping to around -12 or -13°C after the evening rising trend.
Colder Air Returns for the Weekend
Saturday will bring clearing skies as another ridge of high pressure moves into the province. Temperatures will only recover slightly from Friday’s overnight low thanks to a fairly breezy northwesterly wind before dropping into the mid-minus 20’s on Saturday night under clear skies. Sunday looks sunny with a high in the low minus teens and calmer winds.
This week will feature the coldest weather we’ve seen since last winter, just what you were hoping for I’m sure!
Monday
Monday
-12°C / -16°C
Clearing
Skies will clear on Monday morning, giving way to a sunny, but cold day. High temperatures will be in the minus teens with a brisk north-west wind. Watch out for slippery sections on the roads, as freezing drizzle and snow from yesterday will certainly still be an issue on untreated surfaces.
Tuesday
Tuesday
-9°C / -17°C
Mainly cloudy with chance of flurries
Tuesday will be one of the warmer days this week (if you can believe it). Temperatures will hover around the -10C mark with a chance of flurries throughout the day. The mainly cloudy skies will be partly responsible for the warmer conditions, trapping heat near the surface. Winds will be fairly light and from the north-west.
Wednesday
Wednesday
-18°C / -30°C
Mainly Sunny
Wednesday looks to be the coldest day since last winter as a strong surface high descends into southern Manitoba. High temperatures will barely crack the minus teens and lows on Wednesday night could approach -30C. A brisk northerly wind will add a decent wind chill factor as well, making it feel even colder, if that’s possible!
Long Range
The long range forecast looks awful, so there’s barely any point even talking about it. Temperatures look to remain below seasonal for the foreseeable future…hopefully you’re ready for winter, because it’s here!
