Potent Fall Storm Brings Strong to Severe Winds to Winnipeg

Strong to severe westerly winds will be out in full force today behind a cold front now pushing into Ontario. These winds are being created by a very potent fall storm over Northern Manitoba which is also bringing up to 25 cm of snow and blizzard conditions to the most northern regions of the province. The remainder of the week looks beautiful, however, with temperatures rebounding quickly back to well above-seasonal values.

Early morning cloud will quickly push eastwards this morning as very strong westerly winds move into the Red River Valley behind a cold front racing eastwards into Ontario. While skies will be sunny, it won’t be a particularly pleasant day out there as winds quickly increase to 50-60 km/h with gusts of 85-95 km/h. Winds will be just a bit lighter to the south of Winnipeg and a bit stronger to the north of Winnipeg. There will be a few areas that may see wind gusts in excess of 100 km/h: areas just downwind of the Riding Mountains and the Turtle Mountains, the Manitoba Lakes (Manitoba, Winnipegosis, Winnipeg), and across portions of the southern Interlake. These strong to severe winds will diminish quickly in the evening hours as temperatures cool and the low pushes off to the northwest.

RDPS Forecast 10m Wind Speed valid 18Z Wednesday October 18, 2017
Strong to severe (darker purple, red) westerly winds will move across southern Manitoba today behind a cold front associated with a potent fall storm moving through northern Manitoba.

All in all, about 9-12 hours of strong to severe winds are expected, so it will not be surprising if damage to buildings occurs. While the sustained winds may be below the EC³ warning criteria, once winds reach the 60 km/h, the stress incurred on buildings across numerous hours can cause structural failures. Hopefully the worst will just be some missing shingles, but recalling the May 18, 2015 wind storm, significant damage can occur with gusts to 90+ km/h. In that storm, winds were over 50 km/h for 20 hours, which we won’t see this time, but the strongest winds occurred in a 6-hour stretch where winds were maintained in excess of 60 km/h. While this isn’t the same storm, and thus we can’t expect the same outcome, it’s entirely possible that we may see damage that looks familiar.

So, other than the wind, temperatures will fall to around 13°C today as cooler air surges in from the northwest. That said, I don’t think there’s any room for complaints when temperatures remain above-seasonal behind a cold front in October. Lows will dip down to around 3°C with light winds and just a few clouds.

Tuesday will be just a tad breezy by comparison, as another warm front pushes into the region and brings southerly winds of 20 gusting to 40 km/h. Temperatures will climb to a high near 18°C under partly cloudy skies. Winds will remain out of the south at 20-30 km/h on Thursday night as skies become mixed and temperatures dip to a low near 8°C.

GDPS Forecast 2m Temperature Anomaly valid 00Z Saturday October 21, 2017
Temperatures will climb around 15°C above seasonal values on Friday as another surge of very mild air pushes through the province.

Friday will be a late-season “scorcher” in Winnipeg. Despite mixed skies, temperatures will soar to a high near 21°C on Friday afternoon. While we probably won’t be challenging the record high of 23.9°C set in 1958, it may end up coming close if we get enough sunshine. Winds will once again be in place out of the south at 30-40 km/h with some gustiness on top. Expect a low near 13°C on Friday night with winds continuing out of the south to southwest and increasing cloudiness.

Long Range

A second low pressure system will move through Friday night into Saturday, bringing more cloud, cooler temperatures, and a slight chance of showers on Saturday afternoon. While there may be some clearing on Saturday evening/night, more cloud is expected to move in on Sunday ahead of the next low pressure system cross the Prairies. Temperatures will remain above-seasonal throughout the weekend, but after a cold front pushes through on Sunday evening, a west to northwesterly flow will set up for the next few days, bringing seasonal temperatures back to the region.

The extended forecast looks relatively dry, but one wildcard is Saturday and Sunday. Overall, it seems models have having a hard time resolving exactly what kind of low will move through the region, the timing of it, and how much precipitation it will produce. Some models produce little rain with the low coming through — the GFS has essentially no precipitation for much of the Red River Valley — others, such as the GDPS, produce as much as 10-15 mm of rain. The solutions seem to be flipping around quite a bit right now, so it’s hard to pin down exactly what to expect. We’ll certainly be keeping an eye on it and have more details in Friday’s forecast.

Otherwise, next week looks like it will bring variable cloudiness to Winnipeg and the Red River Valley with the occasional chance for some rain showers.

Winnipeg’s seasonal daytime high is currently 9°C while the seasonal overnight low is -1°C.

Brad

Brad lives in Winnipeg with his wife and two children and is the founder of A Weather Moment. He has loved weather from a very young age and has followed that passion through his life so far. He received a B.Sc. in Earth Sciences with Specialization in Atmospheric Sciences and is currently employed in the field of meteorology. You can find the author as WeatherInThePeg on Mastodon.

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