Severe Storm Outlook Narrative (AC)
Issued by NWS
ACUS48 KWNS 190900
SPC AC 190857
Day 4-8 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0257 AM CST Thu Jan 19 2017
Valid 221200Z - 271200Z
CORRECTED TO ADD MISSING WORD
...Southeast Atlantic coast Sunday/day 4...
Substantial cyclogenesis is expected, generally in the immediate lee
of the southern Appalachians, Sunday into Monday morning as a strong
mid-upper shortwave trough traverses the Southeast and Gulf basin.
There are some differences in the details regarding the cyclogenesis
and lingering influences of a lead speed max early in the period.
However, the scenario still appears favorable for a squall line to
form along or in advance of the synoptic cold front which will then
move across parts of FL/GA and the Carolinas. Given an established
moist boundary layer across the Gulf basin already, an unstable warm
sector appears likely in advance of the cold front. Given
weak-moderate buoyancy and very strong low-midlevel vertical shear
in the warm sector, there will be the potential for substantial
severe weather, especially across parts of GA/FL where instability
will be less in question.
...Day 5/Monday and beyond...
In the wake of the strong cyclone/cold front, only limited moisture
return is expected ahead of another cold front that will approach
the Gulf coast days 6-7, along the southern fringe of a
positive-tilt upper trough.