U.S. Severe Weather Forecast (Convective Outlook)

Day Three

acus02 kwns 121729 
Storm Prediction Center ac 121728 

Day 2 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
1128 am CST Thu Dec 12 2019 

Valid 131200z - 141200z 

..there is a marginal risk of severe thunderstorms across parts of 
northern Florida...southern Georgia...and far southern SC... 

A few thunderstorms strong enough to produce isolated damaging wind 
gusts may occur across parts of northern Florida and southeastern 
Georgia, mainly from late Friday afternoon through early Saturday 

..northern Florida/southern Georgia/far southern SC... 
Large-scale troughing over the central/eastern Continental U.S. Will amplify 
Friday as a shortwave trough moves from the southern/Central Plains 
across the lower MS valley and southeast. As forcing for ascent 
associated with the shortwave trough overspreads these regions, a 
weak surface low initially off the coast of la/MS should develop 
northeastward across parts of the southeast to the mid-Atlantic 
while gradually deepening through the period. 

A warm front will lift northward across northern Florida into parts of 
southern Georgia Friday afternoon/evening, with generally lower to mid 
60s surface dewpoints across the warm sector. Low to mid-level flow 
will gradually strengthen through the day, and should markedly 
increase late Friday evening into early Saturday morning. There is 
still some uncertainty regarding how far north into Georgia the warm 
front will reach, and this will impact the northern extent of 
surface-based thunderstorm potential. Regardless, weak instability 
coupled with gradually increasing shear through the 
afternoon/evening should support at least modest storm organization. 
Isolated strong to damaging winds should be the main threat with any 
storms that form along/ahead of an eastward-moving cold front 
attendant to the surface low. As low-level shear increases, a 
tornado or two may also occur if storms can persist from late Friday 
evening into early Saturday morning. 

..Outer Banks of NC... 
Late in the period shear will quickly strengthen across NC/SC as the 
shortwave trough approaches. Most guidance suggests that appreciable 
potential for surface-based convection will remain just off the 
coast of the Outer Banks as the surface low develops northeastward 
and dewpoints gradually increase. At this point, it appears that the 
potential for severe storms should also remain over the Gulf Stream. 

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

.Gleason.. 12/12/2019