U.S. Severe Weather Forecast (Convective Outlook)

Idag
Imorgon
Day Three

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acus03 kwns 170735 
swody3 
Storm Prediction Center ac 170734 


Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0134 am CST Thu Jan 17 2019 


Valid 191200z - 201200z 


..there is a marginal risk of severe thunderstorms across parts of 
Louisiana...Mississippi...Alabama and the Florida Panhandle... 


... 
At least isolated severe storms are expected across parts of the 
Gulf Coast states on Saturday, with wind damage the most likely 
threat. 


..synopsis and discussion... 
A powerful shortwave trough will move rapidly eastward across the 
Gulf Coast states with low pressure moving from Arkansas at 12z Saturday 
to Virginia by 12z Sunday. Southerly winds ahead of a cold front will 
result in modest low-level moistening with lower 60s f dewpoints 
expected across southern la, MS, Alabama and the Florida Panhandle. 
Destabilization will be driven mainly by moisture advection and 
cooling aloft, with the primary severe threat related to storms 
along the cold front. MLCAPE values are forecast to be generally at 
or below 500 j/kg, but 850 mb winds will exceed 50 kt, resulting in 
favorable low-level shear for qlcs structures assuming sufficient 
instability. Thus, damaging winds appear to be the main threat, with 
perhaps a brief/weak tornado especially if pockets of greater 
instability can develop. In any case, severe probabilities may 
increase in later outlooks as details become more predictable. 


Elsewhere, mid 50s f dewpoints are expected to move onshore across 
eastern NC Saturday night in advance of the cold front. Widespread 
precipitation will occur here as well, along with strong low-level 
shear. An isolated severe risk cannot be ruled out here as well, but 
will also depend on boundary layer stability. 


.Jewell.. 01/17/2019 


$$