Southern Manitoba is expected to be impacted by copious amounts of rainfall over the next several hours as showers and thunderstorms continue to blossom over a large part of the northern North Dakota’s.
As these thunderstorms move into a cooler airmass further north, odds are that they may weaken a bit more as MUCapes are only in the 800-1,200J/Kg range anywhere north of Highway 3 and north of Emerson. Better dynamics for severe weather are further south, where MUCAPES are in the 3,000 J/Kg range. Lifted indices and general Instability is lacking albeit moisture is sufficient for copious amounts of rain (PWATS near 40mm) can be expected to fall with dew points in the mid teens and temperatures only a few degrees above the dew pointin much of southern Manitoba, Shear is not even slightly a concern as storms for tonight are not surface based. Tornadoes won’t be a concern from this system. With a warm front parked over southern Manitoba and temperatures remaining quite cooler than average thunderstorms will likely be a issue tonight. What all this means is that strong to possibly severe thunderstorms can be expected throughout the night providing heavy rainfall, small hail and wind gusts possibly over 80km/h, especially in areas along the Canada USA border. Heavy rain is more likely over areas further north, which looks like it should provide sufficient drought relief.
Showers and thunderstorms will continue into the morning timeframe with showers continuing into the afternoon and evening tomorrow. In all 15 to 30mm can be expected with higher amounts in thunderstorms.
Enjoy the rain!!!
-Mike
Most of the abundant areas of energy with CAPE values exceeding 2,000 J/Kg-3000J/Kg max will be situated from the parklands south east into the Red River Valley on into Northwestern Ontario. Shear will be more directional towards tthe parklands and into the inter lakes with bulk shear into the 50 knots range. Shear is less as you go further south into the Red River Valley with still at least 30-40 knots, With ample amounts of instability in place. As the trough line moves through there is a possibility of storms to develop in the Red River Valley ahead of the main batch of storms in the inter lake, if they do they will be explosive as the cap has held back storm development so far today. As the evening goes on expect storms to travel south eastwards and eventually impact the city of Winnipeg and eastern portions of southern Manitoba. The risk for Hail possibly as big as golf balls will persist through the evening as storms have the history of producing hail that size in the northern inter lake. Considering there is a chance of storms becoming weaker as they encounter capping the risk of severe weather would decrease, that’s why we’ll have to monitor storms to see how they react to the warmer air in upper levels. If not then the same risk would apply for large hail up to golf ball size, flooding rains with 50mm in some areas, dangerous cloud to ground lightning, and winds in excess of 90km/h. Storms should clear by late evening, more thunderstorms are expected to travel into southern Manitoba from North Dakota overnight with the best risk to the east in the white shell. Temperatures should only drop into the low 20’s and high teens tonight so not much in the way of cooling expected. I will have a update on tomorrow’s weather in the morning, more storms likely in the afternoon with the Red River valley with the best chance. 
