Hot and Stormy Weather continues

 Much of southern Manitoba has been experiencing off and on scattered thunderstorms this weekend, some of which have been severe. There was a few thunderstorms that created some hail damage in southwestern Manitoba last night. More unsettled weather is on the way.  Let’s have a look and see what exactly will unfold as a cold front moves through. 

A cold front currently draped across central Manitoba will dig south into a hot and humid airmass, sunny skies and clear conditions have been in place for much of the day. Temperatures have soared into the high 20’s to low 30C range with dew points currently sitting in the high teens and low 20C range. Ahead of the front CAPE values of 2,000 to 3,500 J/Kg with Lifted index values from -5 to -8( meaning thunderstorms are likely some severe) are building in southern sections of Manitoba. Looking at shear values in order for storms to maintain themselves EHI values have been consistent in the 0 to 4 range with shear within 25 to 35 knots. Once this cold front moves into the hot and humid airmass thunderstorms should fire and grow upscale into a line of thunderstorms with the potential for large hail and damaging winds in excess of 100km/h, 2 to 4cm hail and rainfall in excess of 25 to 50mm. Thunderstorms will probably form in areas of the Duck mountain to Dauphin regions and points east into the inter lake regions from 5:30pm to 10pm. Then will probably converge and travel further south into the red river valley, southwestern and southeastern Manitoba from the 9pm to 3am timeframe. Some people may not get a thunderstorm depending on how long they maintain strength for and how large an area of the south they cover. 

Environment Canada Discussion: 

THUNDERSTORM FOCUS SHIFTS INTO SOUTHERN MANITOBA TODAY AS A COLD  
FRONT PUSHES SOUTHWARDS INTO A HIGH-ENERGY ENVIRONMENT. SOUTHERLY  
WINDS WILL CONTINUE TO ADVECT MOISTURE INTO THE REGION WITH A POOL OF  
DEW POINTS OF 20-22C GROWING ACROSS THE PROVINCE WHILE TEMPERATURES  
CLIMB INTO THE 30S OVER THE REGION. MLCAPE VALUES WILL CLIMB INTO THE  
2000-3000 J/KG RANGE WITH 0-6 KM BULK SHEAR VALUES OF 15-25 KNOTS.  
THE COLD FRONT, SITTING ALONG A LINE FROM SOUTH-CENTRAL SASKATCHEWAN  
TOWARDS DAUPHIN, MB (CYDN) THEN EASTWARDS ACROSS THE INTERLAKE THIS  
AFTERNOON, WILL SLUMP SOUTHWARDS LATER TODAY IN THE WAKE OF THE  
PASSAGE OF THE EASTERN SASKATCHEWAN LOW.  
  
THIS ENVIRONMENT WILL BE STRONGLY CAPPED FOR MUCH OF THE DAY, BUT THE  
DYNAMIC FORCING OF THE COLD FRONT WILL LIKELY BE ENOUGH TO TRIGGER  
THUNDERSTORMS ALONG THE FRONT BY LATE-AFTERNOON. THESE THUNDERSTORMS  
WILL PUSH SOUTHWARDS WITH THE FRONT THROUGH THE EVENING HOURS WITH  
PRIMARY THREATS OF DAMAGING HAIL AND WIND GUSTS. THE THUNDERSTORMS  
WILL LIKELY BE ISOLATED IN NATURE OVER SOUTHERN SASKATCHEWAN, BUT IN  
MANITOBA THERE IS ENOUGH DYNAMIC FORCING AND DIRECTIONAL SHEAR TO  
SUPPORT UPSCALE GROWTH INTO A BROKEN LINE THAT PUSHES SOUTHWARDS  
THROUGH THE NIGHT.  

Here’s your forecast for tonight.

Winnipeg: Partly cloudy, then increasing clouds with 60% chance of showers or thunderstorms (some may be  severe). Low 23C. Brandon: Partly cloudy with 60% chance of showers and thunderstorms, some may be severe. Clearing before morning. low 17C. Dauphin: Partly cloudy with 60% chance of showers or thunderstorms some may be severe, clearing before morning. Low 14C.

Justin and I will update you on the thunderstorm threat as it develops over the coming hours. -Mike McGregor

A blog will be done tomorrow talking about the week ahead .