Beautiful Weekend Ahead

The Red River Valley will receive a second shot of summer this weekend as warm air floods over the Prairies underneath an upper ridge.

500mb Winds valid Friday evening

500mb wind speeds valid this evening. A large upper ridge will bring warm weather to the Eastern Prairies.

Temperatures aloft continue to climb as an upper ridge advances eastwards across the Prairies. As a result, we’ll see a beautiful weekend ahead across the whole Red River Valley. Sunshine will dominate the skies over the next few days as temperatures climb into the low-to-mid 20’s. We’ll see highs near 23 or 24°C across the Red River Valley today, while things will really heat up tomorrow with highs closer to 26 or 27°C. Some cloud will begin to move into our region on Sunday ahead of an incoming system, which will limit our high to the lower 20’s, probably around 22 or 23°C.

Enjoy a nice summer-like break this weekend to our fall weather.

A Bit of A Mixed Bag For The Long Weekend

Fairly nice weather is ahead for the long weekend with plenty of sunshine and hot temperatures. The only chance for rain will come on Saturday night as a low pressure system passes through the Interlake.

GFS Precipitation for Saturday Night

12 hour rainfall accumulations from the GFS for Saturday night, depicting the showers expected to develop over southern Manitoba.

Temperatures will climb to 30°C today across the Red River Valley as southerly winds build over the region and advect in slightly warmer air. We’ll see an overnight low of around 15°C with clear skies tonight. Tomorrow will likely be a few degrees cooler than today as cloud cover works it’s way into the area in the afternoon. We’ll see slightly stronger winds closer to 30km/h, develop by the afternoon as a low pressure system begins to push across Saskatchewan.

A strong low-level jet (LLJ) is forecast to develop on Saturday evening. Current consensus is that a 40kt LLJ will develop over central North Dakota and slowly push eastwards overnight. An area of showers and thundershowers look to develop on the nose of the LLJ, mainly through areas between the International Border northwards towards Riding Mountain Provincial Park eastwards across the Interlake. There is one great uncertainty with this system, though: Isaac. The storm previously known as Hurricane Isaac will be pushing northwards towards Iowa before shifting it’s track eastwards on Sunday. The moisture required for us to be able to see precipitation on Saturday night sits along a narrow boundary left behind across the Northern US. As it stands now, the LLJ that forms tomorrow evening is supposed to tap into that pool of moisture and transport it northwards into the RRV. Should the track of Isaac change significantly between now and then, the location of the moisture pool may change and move to an area that the LLJ wouldn’t be able to tap into. Should that happen, it’s unlikely we’d see much more than scattered showers over the RRV with little accumulation.

Things will clear out early Sunday morning and we’ll have some sunshine before a few clouds bubble up in the afternoon. We’ll have a cooler day with a high of 25°C.

Holiday Monday looks like a beautiful day with plenty of sunshine and a high once again near 25°C and breezy westerly winds gusting to 40-50km/h.

Red River Valley Set to Bake Today

Some of the hottest temperatures of the year will be seen today in the Red River Valley as extremely warm air is brought into the province by a low pressure system passing through the northern Interlake.

850mb temperatures from the GEM-REG

850mb temperatures from the GEM-REG for late this afternoon. Temperatures are expected to peak at just over 25°C at 850mb over the Red River Valley today.

Southerly winds have brought some of the warmest air yet this year over southern Manitoba. 850mb temperatures have climbed to 25°C today which, when combined with southerly winds at the surface, will help to push our daytime highs towards the mid-30’s. There is fairly good agreement among the models that winds will remain southerly in the Red River Valley through the day; this will eliminate any significant downslope effects and make temperature forecasting a little bit easier.

In general, daytime highs should range from 34-36°C through the RRV tomorrow, with the warmer temperatures closer to the American border. There is a slight chance that a few areas in the SW RRV could see highs push a degree or two higher than that (35-37°C), but such temperatures would be fairly localized. Winnipeg will have a chance of breaking it’s record high for today, which was set in 1972 when the temperature climbed to 36.1°C. It’s by no means a guarantee that we’ll break it, but we’ll certainly take a good run at it.

Dewpoints will climb to around the 18°C mark, however some areas may see dewpoints peak at 21-22°C before we start mixing air near the surface a little deeper into the atmosphere. This will result in humidex values between 39-45. It’s quite likely we’ll see a humidex advisory issued by the Winnipeg SPC later today.

Manitoba Health suggests Manitoba residents take precautions against heat-related illnesses whenever the humidex climbs above 37. Manitoba Health advises the following:

  • Stay aware and be prepared
    • Know daytime and night-time temperatures-both outdoors and indoors- by checking your local weather forecasts and the thermostat in your home.
    • Stay up to date on weather alerts so you know when to take extra-care.
    • If you have an air-conditioner, make sure it’s working properly before the hot weather starts.
  • Stay hydrated
    • Drink plenty of water (that’s the best liquid) before you feel thirsty.
    • Avoid alcoholic beverages, as they can increase the amount of water lost by the body.
  • Stay cool and keep out of the sun
    • Plan outdoor activities for cooler parts of the day, but remember to wear insect repellant since mosquitoes are out too.
    • If you are outdoors during the hottest part of the day, shade yourself from the sun with an umbrella or a wide-brimmed hat with lots of ventilation (to allow the sweat on your head to evaporate), wear loose-fitting, breathable, light-coloured clothing, and remember to wear sunscreen to limit ultra-violet (UV) ray exposure.
    • If there is no air-conditioning at home- go to a cool place such as an air-conditioned mall, public library, or community centre.
    • Take a cool bath or shower or go for a swim to cool off.
    • Avoid using your oven or other appliances that could heat your home more.
    • Limit physical activities during the hotter parts of the day or exercise in an air-conditioned place.
  • Take care of yourself and others
    • Check on family members, neighbours and friends – especially older adults and those with chronic conditions. Visiting is best because it is easier to identify signs of heat illness that could be missed over the phone.
    • Never leave people or pets in your care alone in closed vehicles or direct sunlight.

Heat and Your Health; Manitoba Health

A cold front will sweep through this evening, bringing more seasonal air back to the province. There is very little chance of any precipitation with the passage of this front.

The rest of the week will bring closer-to-seasonal temperatures with daytime highs near 28°C. The normal daytime high for Winnipeg for this time of year is about 22°C. The normal overnight low is around 9°C. Our blast of hot weather will likely ensure that Winnipeg has it’s 14th consecutive month with above-normal temperatures. We’ll have our regular post on Friday, and then two posts on Saturday: the regularly scheduled Elsewhere in Weather News and a climate summary of August/update on 2012.

Hot, Sunny Weather This Week

Winnipeg and the Red River Valley will be basking in hot, sunny weather this week as an upper ridge pushes it’s way across the Prairies. We’ll see a chance of thunderstorms on Thursday evening as a disturbance rolls through the RRV, but quickly return to sunny, warmer-than-seasonal weather.

850mb Temperatures this evening from the GEM-REG

850mb temperatures for this evening from the GEM-REG model. Warm air is building into S. MB bringing daytime highs near 30°C.

A broad southerly flow ahead of an incoming upper ridge has pumped temperatures up over Southern Manitoba back to the 30°C mark. 850mb temperatures will climb up to nearly 20°C today, which will allow our daytime high to soar towards 31 or 32°C. The warm air in place over us will also result in a dramatically warmer overnight low; while the past couple nights have dropped into the low-to-mid teens, we’ll see the mercury barely dip below 20°C tonight.

The normal daytime high for late August in Winnipeg is about 24°C. The normal overnight low is about 11°C.

Thursday will be another warm day, however an incoming shortwave will slide along the International Border through the day, bringing some showers on Thursday morning to SW MB and the risk of an isolated thunderstorm to the Red River Valley, from the Winnipeg area all the way south to Fargo. If storms develop, they’ll develop late in the afternoon along a weak trough line that’s expected to develop in response to the upper feature. Ultimately, I think that most of the storms will remain south of the border with only a very slight chance of anything popping up on the Manitoba side of the RRV. Scott’s Southern Manitoba Mesonet will be a great way to track the trough through the afternoon to see if the threat for storms has passed by you. Despite the heat that will be present with daytime highs near 30°C, dynamics look fairly weak and I do not expect that any storms that may develop will become severe.

We’ll see temperatures dip to around 15°C on Thursday night. On Friday, we’ll see plenty of sun and daytime highs continuing to be near 30°C.

For the weekend, it looks like a cold front will sweep into the province on Saturday, bringing with it some showers and cooler weather; daytime highs look to be in the low-20’s for Saturday. Temperatures look to rebound quickly on Sunday, though, with highs pushing back to the high-20’s. So despite our rather cool start to the month, we may yet come out with our 14th consecutive month of above-normal temperatures in Winnipeg. 5 days out of the next 7 are forecast to have daytime highs at least 3°C above normal, and overnight lows look to remain above normal as well.