U.S. Severe Weather Forecast (Convective Outlook)

Day Three

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Storm Prediction Center ac 150822 

Day 3 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0222 am CST sun Dec 15 2019 

Valid 171200z - 181200z 

..no severe thunderstorm areas forecast... 

isolated thunderstorms are possible across portions of the southeast 
to the coastal mid-Atlantic region, mainly through Tuesday 
afternoon. However, severe thunderstorms are not expected. 

..southeast to the mid-Atlantic... 

The northern and southern branches of the larger-scale mid/upper 
trough over the Great Lakes and the plains will become more in-phase 
on Tuesday as the system as a whole spreads eastward across the 
eastern third of the Continental U.S.. a strong southwesterly mid/upper level 
jet will persist from the southeast to New England. However, 
low-level flow will weaken across the southeast as the surface low 
quickly lifts northeast from the central Appalachians to coastal 
southern New England by 00z Wednesday. The trailing cold front will 
continue eastward across Florida/Georgia and the Carolinas, moving offshore 
after 00z. 

Showers and thunderstorms will likely be ongoing in the vicinity of 
the front from Chesapeake Bay southwest to the northern Gulf Coast 
Tuesday morning. Severe thunderstorm potential appears low at this 
time due to several factors. This includes aforementioned weakening 
low level shear as well as poor downstream thermodynamics. While 60s 
f dewpoints will be in place ahead of the front as far north as the 
eastern Carolinas, widespread cloudiness will limit heating and poor 
lapse rates will further suppress instability. Furthermore, as the 
surface low lifts northeast, low-level frontal convergence will be 
poor, with deep-layer flow parallel to the front. Bands of heavy 
rain, possibly with a strong storm or two, cannot be ruled out 
through early afternoon from northern Florida into southeast Georgia and 
eastern SC/NC, but confidence is too low to include marginal 
probabilities at this time given the limited (both in time and 
space) nature of the threat. 

.Leitman.. 12/15/2019