U.S. Severe Weather Forecast (Convective Outlook)

Day Three

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Storm Prediction Center ac 130048 

Day 1 convective outlook 
National Weather Service Storm Prediction Center Norman OK 
0648 PM CST Mon Nov 12 2018 

Valid 130100z - 131200z 

..there is a slight risk of severe thunderstorms across parts of 
far eastern North Carolina... 

A few severe storms remain possible tonight through early Tuesday 
morning over the coastal Carolinas. 

..01z update... 

..Gulf Coast... 
severe threat continues to diminish across southern Alabama/Georgia and the 
Florida Panhandle as the composite outflow/cold front progresses eastward 
into the somewhat more stable air mass downstream. 00z tlh sounding 
shows a lack of surface-based instability, providing further 
evidence for a continued downward trend in the severe weather 
threat. The sounding does show some elevated instability, supporting 
a continued potential for thunderstorms. More information about this 
region can be found in mesoscale discussion 1640. 

..eastern Carolinas... 
Overall forecast outlined in previous outlooks remains valid for 
this region. Surface cyclogenesis is still expected later tonight 
with the warm-air advection ahead of it contributing to low-level 
moisture advection and the development of surface-based instability 
within the warm sector. Inland penetration of the warm sector will 
be limited but surface-based thunderstorms appear likely across the 
coastal portions of the eastern Carolinas. Large, looping low-level 
hodographs suggest the potential for a few rotating storms, with a 
resultant threat for damaging wind gusts and a brief tornado or two. 

.Mosier.. 11/13/2018 


Mesoscale Discussion

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sels mesoscale discussion 
Storm Prediction Center mesoscale discussion 130026 

Mesoscale discussion 1640 
National Weather Service Storm Prediction Center Norman OK 
0626 PM CST Mon Nov 12 2018 

Areas affected...portions of the Florida Panhandle...far southeastern 
Alabama...and southwestern Georgia 

Concerning...Tornado Watch 427... 

Valid 130026z - 130100z 

The severe weather threat for Tornado Watch 427 continues. 

Summary...severe threat should continue to diminish this evening. 
Additional downstream watch issuance is not expected. 

Discussion...a broken line of thunderstorms will continue eastward 
across southwestern Georgia and the Florida Panhandle this evening. 00z 
sounding from Tallahassee, Florida shows a sharp inversion around 900 mb 
with only weak (less than 500 j/kg) MLCAPE. As the low-level flow 
across this region weakens and veers, convergence along/ahead of a 
surface front should likewise diminish. With the loss of daytime 
heating and the ongoing line of storms becoming increasingly 
oriented parallel to southwesterly mid-level flow, the overall 
severe threat will likely continue to diminish this evening. 
Therefore, downstream watch issuance is not expected, and ww 427 
will be allowed to expire as scheduled at 01z. 

.Gleason.. 11/13/2018 

..please see www.Spc.NOAA.Gov for graphic product... 


Latitude...Lon 30218579 31908441 31858399 29988421 29608485 29548514 
29748542 29928548 30048565 30218579