U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 230729 
Storm Prediction Center ac 230728 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0228 am CDT Fri Aug 23 2019 

Valid 251200z - 261200z 

..there is a marginal risk of severe thunderstorms across portions 
of the northern and Southern Plains... 

Isolated severe thunderstorms are possible on Sunday across portions 
of the northern and Southern Plains. 

Medium-range guidance is in good agreement that a strong shortwave 
trough embedded within the enhanced westerlies moves from the 
northern rockies through the northern plains on Sunday. This results 
in a deepening of the cyclonic flow across the north-central Continental U.S.. 
this pattern evolution will also push a cold front eastward/ 
southeastward through much of northern plains. 

Elsewhere, warm and moist conditions will persist across much of 
Southern Plains and southeast while weakening high pressure across 
much of the eastern Continental U.S. Will allow for some moisture return into 
the Ohio Valley. 

..Southern Plains... 
Air mass across the region will be warm, very moist, and strongly 
buoyant. Strengthening northwesterly flow aloft will also contribute 
to moderate vertical shear. Overall environment would support severe 
potential as long as forcing exists for storm initiation. Current 
guidance suggests a mesoscale convective system will be moving out of Kansas early in the 
period, with a resulting severe threat anticipated downstream. Low 
(i.E. 5%) severe probabilities will be introduced with this 
forecast. More model consistency is needed before issuing higher 

..northern plains... 
Ample low-level moisture (i.E. Dewpoints in the mid to upper 60s) 
will be in place over the region ahead of the approaching cold 
front. Even so, relatively warm low to mid-level temperatures will 
likely limit destabilization, particularly across southern portions 
of the region where less large-scale forcing for ascent (from the 
approaching shortwave trough) is expected. The environment supports 
a severe threat where deep updrafts persists but uncertainty 
regarding coverage currently precludes higher than 5% probability. 

.Mosier.. 08/23/2019