U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus03 kwns 210702 
Storm Prediction Center ac 210701 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0201 am CDT Sat Apr 21 2018 

Valid 231200z - 241200z 

..no severe thunderstorm areas forecast... 

thunderstorms are possible Monday from the Tennessee Valley through 
the Florida Peninsula. Isolated thunderstorms are also possible 
across the Central High plains. No severe weather is currently 

Mature cyclone likely centered near the MS/al/TN border intersection 
at the beginning of the period is expected to only move slightly 
northward throughout the day. Occluded surface low associated with 
this cyclone will remain largely in place while a weak triple-point 
low drifts eastward across southern Alabama and into southeastern SC. 
Thunderstorms will likely be ongoing at the beginning of the period 
along and north of the occluded front between these two lows as well 
as along the surface trough extending southwestward from the more 
southern low. Convection on the surface trough will likely gradually 
weaken as it becomes increasingly displaced from the parent system 
amidst only modest instability. Strong low-level flow is possible 
across portions of eastern Georgia and southeastern SC but, given the 
anticipated frontal position and moist, weak lapse rate profiles 
over the area, any thunderstorms in this region will be likely 
elevated and weak. 

Farther west, a strong shortwave trough will move slowly from the 
northern rockies into the central rockies. Progression of this 
shortwave (as well as an attendant surface low) will encourage a 
southeastward surge of cold air from the northern rockies/northern 
High Plains. Airmass ahead of this front will be relatively dry but 
a warm and deeply mixed boundary layer will likely still support 
modest destabilization and the potential for isolated thunderstorms 
as the cold front moves through. 

.Mosier.. 04/21/2018