/Issued 12:42 PM CDT, Monday, August 27, 2018/
…Enhanced Risk of severe thunderstorms later this afternoon/evening for much of northwest Wisconsin and far eastern Minnesota…
16z HRRR model
Simulated Radar Forecast valid from 2 PM to 11 PM Monday.
Strong to severe thunderstorms possibly in the form of a line or two is forecast to affect northeast and eastern Minnesota and northwest Wisconsin late this afternoon/this evening, approximately from 4 PM to 10 PM, the storms should be moving quickly, and the threat for severe weather will end from SW-NE this evening.
Goes-16 water vapor satellite loop from Monday, August 27, 2018
Loop time: 8:52 AM to 12:07 PM.
Upper level trough moving out of the northern Rockies into the northern Plains this afternoon. Strong lift tied to the upper trough will overspread the upper Midwest through the afternoon resulting in what should be widespread thunderstorm development near and south/east of the cold frontal boundary.
Note: The much cooler temperatures and much lower dew points that are over northern Minnesota this afternoon will move farther south by tonight with a fall feel in the across the entire Northland Tuesday.
Surface map late this morning had a cold front draped from northeast Minnesota to southwest Minnesota with an impressive temperature and dew point gradient in place today. 11 AM temperatures were in the 50s over the northwest half of Minnesota to the mid 70s and low 80s across southern and eastern Minnesota into northern Wisconsin. Late morning dew points ranged from the tropical 70s from the North Shore of Lake Superior through central, eastern and southern Minnesota and northern Wisconsin with near 50 degree dew points behind the cold front across northwest Minnesota.
Showers and thunderstorms should increase in coverage by late afternoon in northeast and east central Minnesota and northwest Wisconsin as forcing tied with the upper trough moves into the upper Midwest, plus the lift with the cold front that is already over the Northland early this afternoon. Some of the storms will likely be severe with damaging winds and large hail, especially over eastern Minnesota into northern Wisconsin. Heavy rainfall is also likely, but storms should be moving quickly, and this should reduce the risk for flash flooding.
Note: Some parts of the Northland will likely be under a watch or warning late this afternoon.
Difference between a watch and warning:
•Watch means that conditions are favorable for severe weather, prepare and stay weather aware.
•Warning means that severe weather is occurring or imminent, take action now!