October Won’t Have a Scary Start

October won’t start off with any scary weather, but I can guarantee the month will end on a frightening note!

Tuesday Will be a Very Windy Day in Southern Manitoba



Mix of Sun and Cloud. Chance of Showers Late.
22°C / 8°C

Today will be a nice day in Southern Manitoba. Temperatures will be in the low twenties, under a mix of sun and cloud. The wind will be breezy and from the south-west. A cold front will push through Southern Manitoba on Monday night, setting up a cooler Tuesday. There may also be some light rain showers associated with this front, but it will be a hit and miss type of rain event.

Tuesday and Wednesday


Increasing Cloudiness
17°C / 4°C

Mix of Sun and Cloud
15°C / 6°C

The first day of October will neither be really good, nor really bad. On the one hand it will be a seasonably warm day, with temperatures in the mid to upper teens. However, it will also be a very windy day, with westerly winds of 40-50km/h gusting to 60-70km/h (winds may reach 60km/h gusting to 80km/h on a localized basis). Unfortunately, that strong wind will make conditions much less pleasant than they otherwise would be.

Wednesday looks to be much less windy than Tuesday, but it will still be on the breezy side. Temperatures will be in the mid teens, with a westerly wind of 20-30km/h gusting to 40-50km/h.

Long Range

The long range forecast is looking more October-like. Another cold front is currently forecast to move through Manitoba on Wednesday night, bringing in cooler conditions to end the week. Models are also hinting at a strong low pressure system passing near or just south of Manitoba later this week. Should this system take a more northern track, it could impact Southern Manitoba…but it’s too early to say.

Active Weather Pattern, but Inactive Weather?

A couple of weather systems are in store for this week, but that doesn’t mean the forecast is wet for everyone.

A Cold Front Will be Positioned Through Manitoba on Monday



Mix of Sun and Cloud. Chance of Showers.
22°C / 8°C

Today will be a warm day by late September standards. High temperatures will be in the low twenties in the Red River Valley. A bit further east in south-eastern Manitoba some areas may approach the mid twenties. But a bit further west in western Manitoba, temperatures will struggle to reach the upper teens. The discrepancy in temperatures over Southern Manitoba today is resulting from a cold front located over western Manitoba. In the vicinity of this front there is extensive cloud cover and some rain activity. Further east, skies are clearer, allowing for the atmosphere to heat up a bit more. Some of the rain showers over western Manitoba may sneak into the Red River Valley later today (as cloudiness increases later today), but little in the way of accumulating rain is expected. Over western Manitoba the rain will probably amount to between 5 and 15mm in general.



Mainly Sunny
21°C / 7°C

Surprisingly, Tuesday will be quite a nice day despite the passage of a cold front on Monday night. High temperatures on Tuesday will be in the upper teens or lower twenties in Southern Manitoba, under sunny skies and light westerly winds.



Mainly Cloudy
22°C / 14°C

Wednesday will see cloudier conditions return ahead of a developing weather system. Temperatures on Wednesday are expected to max out in the low twenties in Southern Manitoba and the wind will be gusty and from the south-east. Some rain may occur over Western Manitoba on Wednesday, but it’s too early to speculate on the location or intensity of it.

Long Range

The long range outlook will be dominated initially be the weather system mentioned in Wednesday’s forecast. This low pressure system is currently expected to track through Manitoba, with its main impacts likely to be confined to the Western half of the province. However, it is possible that this system may change track, so it could potentially affect other parts of Manitoba as well – more details on that will be available in Wednesday’s post.

Once that weather system passes by, conditions should return to near seasonal values for the end of the week. Next weekend is looking fairly pleasant, with near to slightly above seasonably temperatures…but of course that could change before the weekend actually arrives!

Warming Up, Just to Get Knocked Back Down

Temperatures will rebound early this week, but a big weather-maker may interrupt that warm-up by midweek.

Warmer air will move into Southern Manitoba on Monday, but it will be windy.



21°C / 9°C

Today will be bright and sunny with temperatures improving over Sunday’s cool values. Highs will be in the low twenties over Southern Manitoba, which is quite a recovery from this morning’s lows, which were around freezing. The only downside to today’s weather will be a stiff southerly wind that will be 30 to 40km/h gusting to 50 to 60km/h by late afternoon.



Mainly Sunny
27°C / 13°C

Tuesday will be one of the warmest, if not the warmest, days this week with high temperatures in the mid to upper twenties. The humidity may even increase a bit by late in the day over some portions of Southern Manitoba. It certainly won’t be an oppressive mid-summer type of humidity, but may be noticeable nonetheless. Tuesday will be slightly less windy compared to Monday, but the wind will still be fairly strong and from the south.



Mix of Sun and Cloud. Rain late. Risk of a thunderstorm.
25°C / 17°C

What has been a fairly boring weather pattern so far this September may begin to take an interesting turn on Wednesday. A strong low pressure system is forecast to develop in the lee of the Rockies on Tuesday and move eastward into North Dakota by Wednesday. This system will prompt seasonably high moisture values to stream northward into the Dakotas and Southern Manitoba. This moisture will help to destabilize the atmosphere over a large part of the North-Central US, perhaps extending up into Southern Manitoba. This system will also pump warm air up into the region, with models currently suggesting temperatures will once again reach the mid to upper twenties in Southern Manitoba on Wednesday.

As this strong low pressure system interacts with that unstable environment, numerous thunderstorms may develop on Wednesday through Wednesday night. These storms may affect parts of Southern Manitoba at some point on Wednesday or early Thursday. Given the nature of this system it looks like the main severe threat will be heavy rain. However, it is too early to rule out the possibility of other forms of severe weather. We’ll have more updates on this system as the week progresses.

Long Range

The long range forecast will largely be determined by what happens with Wednesday’s system. At this point it appears likely that we’ll receive rain from this system, but the timing of that rain is too early to predict. Unfortunately, once this system moves out of our area it will deliver a parting shot of cold air, which will probably set up a chilly weekend. Again, how cold it will get is still not certain, but getting above seasonal values next weekend may be a struggle.

Warmest Day of Spring So Far Will Also Be Most Unpleasant

It’s almost a certainty that Winnipeg will record the warmest day so far this spring at it’s official reporting station at the airport, but it will without question be perhaps one of the most unpleasant feeling days of the past couple weeks as a low pressure system moves through.

3hr. QPF valid this afternoon.

RDPS output showing a weak band of flurries pushing across the RRV this afternoon.


3°C / -9°C
Cloudy & windy. Chance of flurries midday onwards.

A low pressure system will be tracking through Southern Manitoba today, bringing with it a mass of very warm air. Temperatures at the surface will climb to around +3°C today despite our 850mb temperatures climbing nearly 20°C from yesterday’s values. Thanks to the significant push of warm air aloft moving into the Red River Valley, our winds will be blowing quite strong today out of the south. The winds should sit around 40km/h with gusts to 60km/h through much of the morning, although it’s possible that winds will strengthen beyond that with gusts as high as 70–75km/h.

In addition to the above-zero temperatures, our dewpoint is expected to climb above zero as well. The above-zero temperatures combined with above-zero dewpoints will prove to be one of the more effective melting days we’ve seen so far this year despite the absence of sun with substantial warming of the entire snowpack possible. We may see some flurries as the cold front pushes through in the afternoon, but current indications are that the air coming in is a little to dry to produce much precipitation. Before the cold front comes through, the thermodynamic profile looks relatively favourable for drizzle, but I think that the strong winds will prevent its development. All in all, despite the warmer temperatures, today will end up a cloudy, damp, windy chilly-feeling day.

Once the cold front pushes through mid-afternoon, we’ll see winds lighten and slowly shift to westerlies while gradual clearing occurs. Temperatures will drop to around –9°C tonight under clear skies.

Thursday & Friday


-2°C / -14°C
Mainly sunny.

0°C / -8°C
Mainly sunny. Increasing cloud overnight with chance of flurries.

We’ll return to a benign pattern for the rest of the week as another Arctic ridge builds into the Prairies. We’ll see plenty of sunny skies and highs near or just under 0°C while overnight lows sit around –14°C on Thursday night and warm to just –8°C on Friday night as clouds begin to move in ahead of the next low pressure system. Winds will remain light through Thursday and Friday.

The Weekend

Models are having difficulty resolving exactly what is going to happen with the next system headed our way for late overnight Friday into Saturday. American models are keeping it well to our south, the Canadian models are clipping it through SW Manitoba and the far SW portions of the Red River Valley, while the European models are bringing it through the Trans-Canada corridor, including Winnipeg. While the European models tend to have higher skill than the North American models at long-range (primarily thanks to their relentless efforts to initialize the models as well as they possibly can), the solution doesn’t necessarily make a whole lot of sense to me.

We’ll be watching this system develop over the next few days, and while it seems likely that some snow will fall this weekend over SW Manitoba, it’s still too early to call for Winnipeg or the RRV; we may see nothing or another 5–10cm of the white stuff. At this point, regardless of where it goes, it doesn’t look like a major system that will drop too much water (ensemble solutions are pointing towards 5–10mm of liquid equivalent with this system).


This cool weather of late has many people asking when spring will arrive. Our snowpack is abnormally deep for this time of year, March started off warm but just got colder and colder as time went on, and we have yet to even start the widespread snowpack melt. All this is certainly compounded by memories of last March’s weather, where we had the warmest March on record at 2.2°C, 0.6°C above the previous record.[1] Fortunately, there is some hope on the horizon.

AO Graph

AO values over the past few months. A quick flip from negative to positive values is expected, denoted by the forecast red line.

The Arctic Oscillation (AO), a large-scale weather pattern that can impact the distribution of cold air through the Northern Hemisphere, has been locked below zero for quite some time now. When the AO value is negative, it usually results in a stationary pool of cold air over central continental North America, as we’ve seen over the past few weeks. This has brought below-normal temperatures to many locations across the Prairies and northern United States. The good news is that, as seen above, the AO values are expected to sharply shift into the positive over the next two weeks, which should allow the jet stream to start pushing northwards and bring warmer weather to our region. So while the cooler weather will likely be here for the next 7–10 days at least, a significant change in the weather pattern looks like it’s on it’s way in the near future.

  1. Check out the mentioned link for a list of the 9 significant records we broke in March 2012.  ↩