Severe Weather Returns Hopefully for the last time this year! :(

The rest of today will be an unusually warm and humid day for late August but nonetheless hopefully the last day we see severe weather because of this consistent stormy pattern all summer. Some are getting tired of it and I am especially.

The severe weather threat today will be along and ahead of a cold front that will be encountering a hot and humid airmass. Areas in the light red have the highest risk for supercell development as it is a Enhanced risk, with the sorrounding risk area in orange a strong to Moderate risk. Here are the ingredients we have today

Massive EHI values west of and including Winnipeg.

Moisture: Dewpoints in the high teens to low 20's, PWATS from 40 to 60mm.
Instability: Lifted Index's from -6 to -10C, MLCAPES from 2,500 J/Kg to 3,500 J/Kg and MUCAPES from 4,000 to 5,100 J/Kg.
Shear: Storm Relative Helicity from 165 to 319m2 s-2, Bulk Shear from 30 to 45 knots, EHI's of 3 to 5.3 which means EF2 to EF5 Tornadoes possible especially from Portage east into the Winnipeg and Emerson areas. SigTor from 1 to 3, best risk for significant tornadoes are along the USA border.
Trigger: Powerful Cold Front going through late afternoon to after midnight.

As a result of these ingredients severe weather will be likely as the front encounters the soupy airmass, Supercells will likely develop in the enhanced risk area and points west and persist as they move eastwards, the risk for tornadoes will be present in the enhanced ( moderate risk areas if they stay surface based). At the moment given the SKEW T Graphs and data by the NAM Tornadoes will be a risk (only if they stay surface based) from Portage La Prairie Eastwards through Winnipeg and into the whiteshell areas south to the USA Border. Strong Tornadoes will be possible as a result of such high CAPES and the shear we have. If storms manage to organize early enough and possibly become elevated the risk will only present itself west of Winnipeg. Regardless storms will organize into a squall line that will impact the Winnipeg and Red River Valley in the mid evening hours (if they are surface based they will pose a tornado threat as well, squall lines can be surface based). The storms will pose a threat for large hail up to softball size, winds in excess of 100km/h, heavy rainfall up to 100mm possible in locales, and dangerous frequent lightning. The storms will swing east southeast into North Dakota in the midnight timeframe. People are urged to follow updates from Manitoba Weather Center and Environment Canada for updates.


Storms will clear overnight leaving behind cooler and sunnier weather for the first half of the week before more heat and storms arrive to start September.