A Smoky Transition Back to Summer Heat

Today will be a bit of a mixed bag here in Winnipeg as a dying cold front completes its slump into Southern Manitoba bringing a chance of showers alongside another batch of forest fire smoke gradually working into the Red River Valley. Fortunately, winds will become more southwesterly as the week progresses, pushing the smoke to our north and bringing back hot summer weather to the area.

Today will start off with a slight chance of showers or thunderstorms until around midday after which the clouds will start pushing off to our southeast and see increasingly smoky skies build in. Temperatures will only climb to around 21°C today and then dip down to the low teens tonight.

NOAA 1hr. Vertical Smoke Forecast valid July 08, 2015 7PM EDT
The “total smoke” product from NOAA is forecasting a thick layer of smoke across Southern Manitoba by this evening.

Thursday and Friday will herald the return of summer. Winds will shift more westerly to southerly and begin tapping into warmer air to our south. There should be a deep enough layer of southerly winds to push the smoke north of Winnipeg through the day. Temperatures will be soaring into the upper 20’s on both days under mainly sunny skies.

The biggest difference between Thursday and Friday will be the humidity; while dew points in the mid-teens on Thursday will make it feel slightly humid, it’s expected that dew points will climb up to the 20°C – or even a bit higher – for Friday, making it feel downright tropical out there.

Overnight lows on Thursday & Friday will be in the upper teens.

Unsettled Weekend?

Weather models are pointing towards a potentially unsettled weekend as a large upper-level low lifts northwards into Alberta with a deep trough extending southeastwards across the Prairies.

GDPS 24hr. QPF valid 00Z July 13, 2015
Total precipitation forecast from Saturday evening to Sunday evening from the GPDS.

It’s not worth getting caught up in details at this point when dealing with a large, highly convective system such as this. The main thing to take away is that with a large low lifting into Alberta, it’s likely our weekend will continue humid, warm and potentially bring some wet weather.

Mainly Sunny with a Good Chance of Smoke

Several forest fires have produced widespread smoke over Southern Saskatchewan & Manitoba .
Several forest fires (circled in red) have contributed to the widespread smoke over our region the past week.

This week will see relatively benign weather, but unfortunately also the continuation of forest fire smoke over southern Manitoba. A persistent west to north-west flow aloft will continue to transport smoke from northern Saskatchewan into southern Manitoba.

Monday

Today will see cool conditions in southern Manitoba as a chilly air mass surges down from the arctic. High temperatures are only expected to be in the mid teens, but skies will be mainly sunny. Surface winds will be breezy from the north.

Tuesday

Tuesday will see somewhat warmer conditions from Monday as some warmer air begins to return from the south-west. High temperatures should reach the low to mid twenties under mainly sunny skies. The only unknown in Tuesday’s forecast is how extensive forest fire smoke will be over the region. Should smoke be quite extensive, temperatures will likely stay closer to 20C, whereas less smoky skies will promote temperatures in the mid twenties. Our forecast is a compromise position between these two possibilities.

Wednesday

Temperatures are expected to remain near to slightly below seasonal for Wednesday, with highs in the low to mid twenties. There is a decent chance of showers or thunderstorms during the day as some mid-level instability develops in the atmosphere. Severe storms are not expected, but do not be surprised to hear some thunder!

Summer Warmth and Smoke Lead into an Unsettled End to the Weekend

Widespread smoke will remain in place today as a northwesterly flow gradually lightens and leaves the smoke to languish across Southern Manitoba. A low pressure system tracking into the northern Prairies tonight will bring a southerly flow at all levels to Southern Manitoba which will help clear skies out as well as lead towards an unsettled end to the weekend.

Today will bring partly cloudy skies which will seem a whole lot cloudier thanks to the widespread smoke that remains entrenched over Southern Manitoba today. That smoke will keep our temperatures slightly cooler than they would be under clear skies, leaving us with a high temperature later today of 26°C. Winds will remain fairly light through the day. The humidity will be more comfortable than yesterday’s dew points of 20°C; dew point values are expected to sit in the low- to mid-teens this afternoon.

Winds will begin picking up out of the south overnight which should help begin clearing the smoke out of our area. Our temperature will dip down to around 17°C.

Saturday will bring the humidity back to Southern Manitoba alongside gusty southerly winds to 30–40km/h. It will be quite a warm day with temperatures soaring into the upper–20’s or even hitting the 30°C mark while dew point values climb back towards the 20°C mark as the southerlies bring in more humid air from the Northern Plains.

GDPS 12hr. QPF valid Sunday morning.
The GDPS continues to forecast a swath of nocturnal convection occurring on Saturday night.

Saturday night will see thunderstorms initiate over Western Manitoba then slowly push southeastwards. There will likely be a chance for some severe thunderstorm activity over Parkland Manitoba; we’ll take a closer look and issue a convective outlook if warranted tomorrow. These showers and thunderstorms will slowly stall out towards the Red River Valley near morning and then sit over the region for much of Sunday. Temperatures will climb to a very humid 23°C or so on Sunday before the cold front finishes pushing through.

Behind the cold front, cooler and less humid air will begin working back into Manitoba. Sunday night will see the coolest overnight low in a while as it dips towards the low teens. With that cooler, drier air will come a northwesterly flow which will likely mean a return to smokier conditions.

Smoke over SK & MB - June 28, 2015

Smoky with a Risk of Thunderstorms

This week will start out with hazy skies from forest fires burning over Northern Saskatchewan and Alberta. There will also be a risk of thunderstorms today as a cold front moves through southern Manitoba.

Monday

Today will feature hazy skies, as extensive smoke from northern Saskatchewan/Alberta continues to pour south-eastward into southern Manitoba. The smoke will likely hold down high temperatures to the mid twenties, when they would otherwise be in the upper twenties. Despite the cooler temperatures, it is still expected that storms will develop along a cold front ahead of an incoming upper disturbance. At this point it appears that storms will be strong to marginally severe, with the highest potential for severe storms being in south-eastern Manitoba. The main threat with storms tomorrow will be large hail, although gusty winds are also possible. The main uncertainty surrounding tomorrow’s storm threat is how much the smoke will affect atmospheric (in)stability. If smoke is less extensive than expected, storms could potentially be stronger due to extra daytime heating.

Tuesday

Tuesday will be a nice day, with temperatures in the mid twenties under mainly sunny skies and light winds. There may still be some lingering smoke, but it shouldn’t be as extensive as earlier in the week. No precipitation is expected.

Wednesday

Wednesday will be another pleasant day in southern Manitoba. Temperatures will be in the mid to upper twenties under mainly sunny skies. Winds will be light once again and there is only a slim chance of showers.

Long Range

The medium-term forecast suggests we’ll generally see normal to above-normal weather for the next week or so. Beyond that it appears there may be slightly more unsettled conditions as we see more frequent chances for stronger weather systems passing through the region.