Cool Weekend Ahead; Light Snow Possible Saturday

The weather will be relatively quiet over the coming few days with slightly below-seasonal temperatures in place. The only real weather to note will come on Saturday as a weak low pressure system tracks along the US-Canada border and brings the chance for some light snow to the region.

Today will bring a daytime high near -8°C with partly cloudy skies and light winds. Expect a low near -13°C tonight with increasing cloud.

Saturday will be a mostly cloudy day as a low pressure system skims along international border. Temperatures will top out around -6 or -7°C in the Red River Valley with a decent chance of some light snow in the region, particularly through the afternoon. Minor accumulations may occur, but only really enough to make roads a bit slick again. Winds will continue to be fairly light. Temperatures will dip down to around -14°C on Saturday night with clear breaks developing.

The 00Z run fo the RDPS shows the potential for 1-3cm of snow on Friday across southwest and south-central Manitoba.

Sunday will be be a return to quiet weather with a high near -6°C, light winds and mixed skies. Lows will drop to around -12°C on Sunday night with mixed skies continuing.

Ultimately, there’s a slack pressure pattern for the coming few days and with the storm track well to our south. This will result in a few days that are mostly slight variations of each other.

Long Range

Temperatures are expected to return to seasonal values for much of next week. At this point, it appears that there are no threats for any notable snowfall events until late next week, so fairly quiet weather ahead.

Winnipeg’s seasonal daytime high is currently -6°C while the seasonal overnight low is -16°C.

Cooler Temperatures Settle Back Into Southern Manitoba

Cooler temperatures are moving back into the region today behind a cold front that passed through overnight. This cooler weather will persist for several days as an upper-level trough builds over the Prairies, driving the jet stream southwards.

Winter will gradually slump back into Winnipeg as cooler weather slowly pushes southwards through the Prairies, although temperatures will be moderated by an extensive area of low-level clouds that will likely take their time in breaking up.

Today will be the warmest day of the next few with temperatures topping out near 0°C, although a northerly wind at around 20 km/h will be tapping into cooler air to the north. Skies will remain cloudy, though, and a few remaining morning flurries will exit the region early, leaving behind a slight chance for some freezing drizzle. The chance for freezing drizzle will continue overnight as temperatures drop to a low near -8°C.

A cooler air mass will slump southwards over the next few days.

Thursday will continue with fairly cloudy skies; there’s some uncertainty as to how much clearing will manage to occur through the day but in general, expect skies on the cloudier side through the day. Temperatures will climb to a high near -4°C with light northerly winds continuing. Skies may clear a bit in the afternoon, but I’m leaning towards cloudier conditions. We’ll have to see how/if the low cloud begins breaking up over the northern Prairies today as to how much clearing we may see on Thursday. Temperatures will drop to around -11°C on Thursday night with mixed skies.

Friday will bring partly cloudy skies, relatively light winds and a high near -7°C. Not much to say about it! Expect a low near -16°C on Friday night with partly cloudy skies.1

Long Range

Temperatures will continue at near-seasonal values with not too much in the way of snow. Some guidance hints at a system that would bring 2-5 cm of snow to the region on Sunday, but there’s still disagreement on that. After that, it appears that there may be another chance for snow mid-week next week. All in all, though, fairly quiet weather ahead!

Winnipeg’s seasonal daytime high is currently -6°C while the seasonal overnight low is -17°C.

  1. While -16°C is our best bet at the moment, guidance suggests a low somewhere between -14 and -20°C. 

Rain Expected Today In The Red River Valley

A complex low pressure system moving across Manitoba today likely bring record-breaking rainfall to Winnipeg as showers develop along a cold front sweeping eastwards. Behind this feature, things will cool slightly, returning the region to near-seasonal temperatures with a few chances for some light snow.

Today’s main weather story will be a low pressure system lifting northeastwards through the Interlake that will push a cold front eastwards across the Red River Valley & Whiteshell. Ahead of this front, temperatures will climb to a high near 4°C with light southerly winds. As the front pushes through later this morning, an area of showers will develop and spread eastwards. The rain has the potential to be relatively heavy (for February in southern Manitoba), and will produce a swath of accumulations generally in the range of 4-8mm, with lower amounts to the west of the main development and localized potential for 8-15mm although those higher amounts would likely be restrained to near the Ontario border.

The NAM’s simulated RADAR imagery shows the main area of rain passing just to the southeast of Winnipeg.

There’s a little uncertainty as to how far west and north the precipitation will push, however it seems likely that Winnipeg will see some rain with 2-5 mm very likely. There’s a smaller chance that we’ll see amounts higher than that, but that will become more clear this morning as the rain develops. Winnipeg’s daily rainfall record for February 20th is 0.3 mm, set in 1965. This makes breaking the record almost a near-certainty today.

Winds shift out of the west behind the front to west-southwesterly at around 20-30 km/h. Temperatures will fall to a low near -1°C overnight under mostly cloudy skies.

Tuesday will bring a mix of sun and cloud to the region with mild weather still in place as temperatures climb to a high near 3°C. Expect increasing cloudiness on Tuesday night with temperatures dropping to a low near -2°C.

Wednesday will bring another low pressure system to the region, this time skirting across southern Manitoba near the US border. This system will spread an area of snow along and just north of the low track. Total amounts, at this point, look like 5-10 cm over the southwestern portion of the province, tapering off to 4-8 cm over the Red River Valley and 2-5 cm over the southeastern corner of the province. Winnipeg’s high temperature will climb to around -1°C, but temperatures may climb to 0 to +1°C over the southern Red River Valley if the low tracks far enough north. Expect a low near -8°C on Wednesday night with gradually clearing skies.

Long Range

The long-range forecast looks cooler, but still relatively pleasant. Winnipeg will likely see variable cloudiness through the second half of the week as temperatures fall back to seasonal to slightly below seasonal temperatures. Nothing significant is expected for snow between Thursday and the end of the weekend.

Winnipeg’s seasonal daytime high is currently -7°C while the seasonal overnight low is -17°C.

A Danish Astronaut Captures Rare Blue Flashes ↦

Eric Berger, writing for Ars Technica:

Scientists don’t know much about the mysterious, powerful electric discharges that sometimes occur in the upper levels of the atmosphere in conjunction with thunderstorms. The first photograph of the phenomenon—which can occur as high as about 90km above the surface of the Earth and are known variously as sprites, pixies, elves, or jets—was only taken from Earth in 1989.

Fortunately for scientists interested in these storms, the International Space Station offers an excellent vantage point at an altitude of about 400km. So Danish researchers devised a “Thor experiment”—named after the hammer-wielding Norse god—to study the phenomenon. As part of the experiment, an astronaut on board the station would image thunderstorms under certain conditions, and these observations would be correlated with data collected by satellites and ground-based radar and lightning detection systems.

It has been interesting seeing more and more proper research going into these upward-directed electric discharges from thunderstorms. I recall just in the early 2000’s stories about pilots who had seen these phenomenon but didn’t share their experiences because they felt people may not believe them.

Now we know not only that these blue flashes exist, among other upper-atmosphere related phenomenon, but also that thunderstorms may have a role in troposphere-stratosphere gas exchange.

Interesting stuff. Follow through the link for more photos; the published paper with findings is available here.1

  1. Chanrion, O., T. Neubert, A. Mogensen, Y. Yair, M. Stendel, R. Singh, and D. Siingh (2017), Profuse activity of blue electrical discharges at the tops of thunderstorms, Geophys. Res. Lett., 44, 496–503, doi:10.1002/2016GL071311.