U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 190718 
Storm Prediction Center ac 190717 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0217 am CDT Tue Sep 19 2017 

Valid 211200z - 221200z 

..there is a marginal risk of severe thunderstorms across eastern 
North Dakota and northern/central portions of Minnesota... 

A few hail-producing storms are possible in portions of Minnesota 
and eastern North Dakota Thursday night. 

An amplifying longwave trough across the west will become nearly 
stationary with time, while a mid/upper ridge becomes established 
across the Great Lakes and Ohio Valley. At the surface, 
cyclogenesis will begin in earnest across the northern plains as a 
ridge becomes dominant across the northeast and Appalachians. 
Southerly low-level flow across much of the center of the country 
will result in a moist low-level airmass retreating northward, with 
60s f dewpoints reaching the Minnesota/Ontario border overnight. 

..eastern North Dakota and northern/central Minnesota... 
The amplification of the long-wave trough in the west will result in 
backing mid/upper flow and subtle height rises during the day, which 
should keep daytime convective potential at a minimum. In the 
evening, however, strengthening low-level flow will occur in 
conjunction with a 50-55kt 850mb jet across the Central Plains, and 
convergence on the nose of this synoptic-scale feature will Foster 
scattered thunderstorm development primarily after 00z. Steep 
mid-level lapse rates and kinematic profiles will result in 
primarily a hail threat with elevated convection occurring across 
the region. Marginal (5%) severe probabilities have been added to 
address this threat, and later outlooks may needed higher 
probabilities if more focused corridors of hail potential become 

.Cook.. 09/19/2017