U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 050720 
Storm Prediction Center ac 050719 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0219 am CDT Sat Sep 05 2015 

Valid 071200z - 081200z 

..there is a marginal risk of severe thunderstorms from the Central Plains into 
the lower MO valley... 

A few strong to isolated severe thunderstorms will be possible 
Monday afternoon and evening over parts of the Central Plains into 
the lower Missouri River valley. 

An upper low is forecast to move eastward across the Canadian prairie 
provinces with weakly cyclonic flow spreading eastward across the upper 
Midwest. At the surface...a cold front will settle southward from the 
Great Lakes into the Central Plains...although convective outflow 
from storms late Sunday night/Monday morning may result in multiple 
mesoscale boundaries to focus redevelopment of storms during the 
afternoon peak-heating period over the Central Plains into the lower 
MO valley. 

..Central Plains into the lower MO valley... 
Early storms are expected to gradually weaken during the morning but 
the effects of remnant cloud cover may delay onset of stronger 
diabatic heating over some areas. Ample low-level moisture and 
pockets of stronger heating will promote diurnal destabilization 
with maximum MLCAPE of 2000-2500 j/kg expected during the afternoon. 
Weak convergence along the front and other mesoscale boundaries 
coupled with low-level heating will weaken the cap sufficiently for 
strong storms to develop during the afternoon and evening. With the 
stronger flow aloft displaced to the north over the Dakotas and 
Minnesota...the effective shear over the discussion area will be modest 
/25-30 knots/ suggesting potential for primarily weakly organized 
multicell storms. This is expected to limit the overall severe 
threat although isolated severe cells capable of producing hail and 
strong wind gusts will be possible during the afternoon and evening. 

.Weiss.. 09/05/2015