U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 181714 
Storm Prediction Center ac 181713 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1213 PM CDT Tue Sep 18 2018 

Valid 191200z - 201200z 

..there is a marginal risk of severe thunderstorms from the High 
Plains of Wyoming and Colorado into southern Minnesota and western 

A few severe storms are possible across parts of the northern plains 
and upper Mississippi Valley on Wednesday, mainly during the 

..synopsis and discussion... 
An upper high will shift east from the lower Mississippi Valley 
toward Kentucky and Tennessee, providing very warm temperatures 
aloft, while an upper trough develops across The Rockies. Increasing 
southwesterly winds aloft will develop across the northern plains 
into the Great Lakes ahead of the upper trough, with increasing lift 
during the evening. At the surface, a stationary front will extend 
from a Lee trough over eastern Colorado northeastward into central 
Wisconsin, with a moist air mass along and south of the boundary. 

..northern plains into the upper Mississippi Valley... 
Scattered thunderstorms may be ongoing across the upper Mississippi 
Valley Wednesday morning on the nose of a weak southwesterly 
low-level jet. These storms are not likely to be severe, but may 
contain small hail and heavy rain. More vigorous and widespread 
thunderstorms will occur after 00z mainly from northeast Colorado 
into Wisconsin as warm advection increases during the evening, near 
or just after peak destabilization. Hail will be the primary threat 
as most of the storms will be north of the surface front. 

..maximum risk by hazard... 
Tornado: <2% - none 
wind: 5% - marginal 
hail: 5% - marginal 

.Jewell.. 09/18/2018