Valid 232000Z – 241200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Isolated thunderstorms remain possible this afternoon and evening
from the eastern portion of the Southeast States to the Ohio Valley.
No severe weather is expected.
…Southeast States through the Ohio Valley…
Isolated thunderstorms remain possible within a general area of
showers along warm conveyor belt across the Southeast States from GA
and northern FL to the Carolinas this afternoon and evening. A
somewhat Greater coverage of thunderstorms has occurred across the
TN and OH Valleys within corridor of ascent and steeper mid-level
lapse rates accompanying a progressive vorticity maximum.
.PREV DISCUSSION… /ISSUED 1033 AM CST Sat Nov 23 2019/
…Southeast through tonight…
A midlevel shortwave trough over middle MS Valley will begin to
accelerate eastward in response to loose phasing with a northern
stream shortwave trough traversing the upper Great Lakes. An
initial surface cyclone will develop north-northeastward to the
immediate west of the Appalachians, while secondary cyclogenesis is
expected overnight near the Mid Atlantic coast. To the south of the
cyclones, a surface cold front will progress eastward across AL/GA
today, and the Carolinas/north FL overnight. Ahead of the front, a
modifying air mass with boundary-layer dewpoints from the mid 50s to
lower 60s is present across north FL/GA this morning. Only modest
additional modification is expected inland through the period with
rather poor lapse rates aloft, which both suggest that buoyancy will
remain quite weak within the warm sector. Thus, expect only
isolated, low-topped thunderstorms along and ahead of the front
today through tonight across the Southeast states — the more
widespread convection likely overnight over the Gulf Stream with
more substantial low-level destabilization.
Given the expected very weak buoyancy inland, the threat for severe
storms will likewise remain quite low. Shallow, forced convection
along the front could pose some low-end threat for damaging winds,
whether or not lightning is observed. Still, this threat appears
too marginal to warrant adding an outlook area.