A very warm and moist air mass resided across southern Manitoba Thursday afternoon, with dewpoint temperatures reaching 25 C. A cold front, in association with an intense upper trough, was forecast to sweep northeastward from North Dakota into southern Manitoba Thursday evening. Ahead of the cold front, severe thunderstorms – with a primary threat of large hail – were a high probability.

I observed a large, isolated thunderstorm developing just north of the International Border around 7:00 PM, moving northeast at 30 km per hour into southern Manitoba. I opted to intercept this storm as it approached highway 75 near Morris, MB.

As I intercepted the storm, it was apparent that it was evolving from an isolated cell into a linear MCS, with intense electrical activity, wind gusts measured to 85 km/h and quarter sized hail.

In summary, this storm was well worth the short trip south of Winnipeg to witness the amazing “anvil crawlers” that lit up the sky in almost every direction. I found a nice vantage point just north of the precipitation to take some memorable pictures of this event that persisted until well after 11:00 PM. Opportunities like this are a rare treat in September.