It will be a very windy Thanksgiving as a strong low pressure system ushers in potentially damaging winds. By the time you’re reading this your loose objects will probably already be in your neighbour’s yard!
Monday
Today will not be the most pleasant Thanksgiving, as rain and strong winds wreck havoc outdoors. A strong low pressure system and corresponding pressure gradient will generate high to extremely high winds over southern Manitoba on Monday. The highest winds are expected Monday morning, when sustained speeds of 60-80km/h, and gusts to 100km/h or more, are expected. The period of extreme gusts likely won’t last more than a few hours, but during that time it will certainly do some damage, not to mention the fact that you’ll have a lot more leaves to rake!
A strong pressure gradient (shown above as tightly packed black lines called isobars) will bring very windy conditions to southern Manitoba on Monday
Today will also be rather soggy, as moderate rainfall occurs in association with this low pressure system. Today’s rainfall amounts will likely be around 5-15mm in the Red River Valley. You’ll have to wait until at least Tuesday for all those wet leaves to dry out!
Tuesday
Tuesday will be much calmer than Monday. Temperatures will climb into the mid teens under mainly sunny skies. Winds will remain breezy from the west, but they will feel light compared to Monday!
Wednesday
Wednesday will feature much the same weather as Tuesday. Temperatures will be in the low to mid teens under mainly sunny skies. Winds will be breezy from the north-west, but once again it will feel like nothing compared to Monday.
Long Range
Long range models continue to show a strong signal for warmer than normal weather through the end of October. Hopefully this will continue to be the trend as we move into winter due to the effects of El Nino.
A low pressure system moving across Southern Manitoba today will produce some rain this afternoon that may have a slight risk of an isolated thunderstorm in the heavier bands. This system is on the leading edge of a large-scale pattern shift that will transition the region into a warmer, but windier, regime for the end of the week and extending through Thanksgiving weekend.
Today will be a bit of an unpleasant day; moderately strong southeasterly winds will develop through the morning to around 40 km/h (with some gusts on top of that) by this afternoon while temperatures struggle from a chilly sub-zero low to just the low-to-mid teens. The strengthening winds will be courtesy an approaching low pressure system that will push across the Red River Valley later today; this system will be responsible for some widespread shower activity late this morning into the afternoon hours that will push from west to east across southern Manitoba.
The RDPS is showing 5-10mm of rain through the RRV with this system, however pockets of 10-15mm appear possible.
Winds will diminish as the low passes by in the evening. Expect mainly cloudy skies overnight with a low near 6 or 7°C.
Seasonal Temperatures Lead to Weekend “Heat Wave”
Thursday and Friday will both be fairly similar days thanks to a ridge of high pressure dominating the region. Winds will be relatively light, skies fairly sunny[1], and temperatures fairly seasonal with daytime highs near 13°C and overnight lows near in the –1 to 4°C range.
The winds will begin to pick up out of the southwest on Friday evening as the ridge of high pressure moves off to the east and a more zonal flow pattern begins to develop for the weekend.
This zonal flow pattern will result in much warmer air pushing eastwards across the Prairies, sending temperatures soaring 5–8°C above normal for this time of year. At this point, it looks like daytime highs will be around 20–22°C this weekend with winds in the 20–30km/h range.
No precipitation is expected on Saturday or Sunday, however a cold front pushing through Sunday afternoon may bring in some breezy winds. For Thanksgiving Monday, pleasant conditions with highs in the mid-to-upper teens are expected. Winds will likely be breezy out of the west to northwest, though, at around 30km/h.
The NAEFS continues to forecast above-normal temperatures for Western North America in the 8-14 day range.
Further down the road in the 8–14 day range, the NAEFS continues to forecast above normal temperatures for western North America. There isn’t a whole lot to say about it, so just enjoy the (relatively) pleasant weather outside. If a frosty morning here or there has you down, just remember that it’s October and we’re looking at 20°C+ highs for Thanksgiving weekend!
Except for Thursday morning, where any remnant cloud from today’s system will be clearing out. ↩
After a pleasant, summer-like start to the week, the weather is set to turn more unsettled as a disturbance rolls through Southern Manitoba tonight. Fortunately, the agitated weather will only bring temperatures back towards seasonal values before we see the heat move back in through the weekend, setting Winnipeg & the Red River Valley up for a hot start to next week.
Today will be a fairly pleasant day in the Red River Valley. There’s a slight chance of some shower activity early this morning as a trough passes through the region, but afterwards we’ll see the cloud begin to clear out through the remainder of the morning leading to just a few clouds this afternoon through the region. Daytime highs will climb to around 21°C–but with significantly less humidity than yesterday–with winds initially out of the northwest at 20–30km/h tapering off through the morning.
The more significant weather will roll into the province this evening as a low pressure system lifts northeastwards out of North Dakota and pushes across southern Manitoba. An area of showers, likely with thunderstorms embedded, will develop across southern Saskatchewan and northeastern Montana and spread eastwards through the night, pushing into southwestern Manitoba early in the evening and then spreading into the Red River Valley and Interlake through the remainder of the night. As is typical with systems that involve convection through the night-time hours, model solutions are a little scatter-shot as to what the outcome will be. Overall, it appears that the bulk of the precipitation will pass to the north of Winnipeg, however some models are coming up with solutions that bring significantly more precipitation into the region.
This simulated RADAR image from the NAM forecast valid on Thursday morning shows a band of heavy, convectively-driven rain over Winnipeg & the Red River Valley.
The NAM-based solutions all tend to produce fairly strong, convectively-driven rainfall over the Red River Valley late tonight into Thursday morning. With PWAT[1] values near 35mm, the rainfall could be quite intense, however strong winds aloft should be moving anything that develops along at a fairly decent clip, meaning overall rainfall accumulations shouldn’t be excessive with around 10–20mm in any heavier precipitation that develops. Outside of thunderstorms/heavy rain cells, the more general rainfall amounts from this system should be around 2–5mm or so in regions south of the Trans-Canada Highway, and closer to the 5–10mm range for areas northwards.
This forecast sounding for Winnipeg from the NAM for Thursday morning indicates heavy rain or thunderstorms may be possible.
Temperatures will dip to around 14°C tonight. Thursday will see a high near 15°C with winds increasing out of the northwest to 40 gusting 60km/h in the afternoon. A chance for showers will persist through the remainder of Thursday under mainly cloudy skies.
Friday will bring calmer weather to the region with mainly sunny skies and a high near 19°C. Winds shouldn’t be too bad at around 15–20km/h.
Warmer Weather Returns on the Weekend
Our cool-down to seasonal temperatures will be short-lived, however, as warmer weather is set to build back into Manitoba through the weekend. The upper-level trough that will bring us our unsettled weather will push off to the east and a zonal flow is forecast to quickly develop across the Prairies, pushing in warmer air aloft that will begin to bump our temperatures back upwards. Saturday looks to have a high around 20°C, while Sunday will see the mercury climb towards the mid–20’s.
This forecast of 850mb temperatures from the GDPS shows temperatures pushing into the upper teens on Monday morning.
The GPDS is forecasting 850mb temperatures pushing into the upper teens through Monday, which would equate to temperatures in the upper 20’s as long as we see the sunshine. Afterwards, it looks like we may see a couple more disturbances roll through in the remainder of the week, bringing temperatures back towards seasonal.
While we will have occasional cool-downs, long-range forecasts continue to forecast above-normal temperatures through the remainder of September.
Benign weather will continue over the Red River Valley for the next few days as a weak ridge of high pressure remains entrenched over the region until Friday. Heading into the weekend, however, it looks like rain may be possible as a low pressure system moves into the region through the day.
There isn’t a whole lot to say regarding the coming days, so I’ll keep this post fairly brief! The weather for today and tomorrow will be largely dictated by a weak ridge of high pressure over the region that’s more a result of larger low pressure systems to our west and east than being particularly potent in and of itself.
Today will see temperatures climb to around 23°C with breezy winds building out of the north to 30–40km/h thanks to a low pressure system passing to our east. The day will start overcast with some mid- to high-level cloud that will gradually clear out through the day. Winds will taper off this evening as low temperatures head to around 9°C.
Thursday will be mainly sunny day with light winds and a high near 25°C. Expect a low near 13°C on Thursday night.
The GDPS is showing a low pressure system moving through Southern Manitboa on Friday night capable of bringing some rain to the Red River Valley.
Friday will see increasing cloudiness, particularly in the afternoon as a low pressure system begins working into the region. Temperatures will climb to around 25°C. Friday night will likely bring some rain, although specifics are still quite fuzzy. Temperatures will dip back down to around 13°C again.
Mixed Weekend
This weekend looks mixed at this point, with slightly cooler, cloudier weather on Saturday with a chance of showers and sunnier conditions on Sunday. There’s quite a bit of uncertainty with Friday night/Saturday’s low pressure system, so it’s a bit early to make much in the way of concrete forecasts. High temperatures will likely be in the low 20’s with a chance of warmer weather returning for the beginning of next week.
