Valid 012000Z – 021200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Organized severe thunderstorms are not expected through tonight.
19Z surface analysis placed a low over southwest Lower MI with a
warm front extending east-southeastward to another low near the
Chesapeake Bay. This second low is deepening (-6 mb surface pressure
change over the last 2 hours at NUI) and will soon become the
primary surface low associated with the mature mid-latitude cyclone.
Additionally, a cold front extends from this second low
southwestward along the Carolinas coast and into northern FL.
General thunder line was trimmed to reflect this
eastward/southeastward progression with a few thunderstorms still
possible across FL this afternoon and evening.
Lightning will also remain possible amidst the strong forcing for
ascent near the upper low currently over the upper OH Valley.
Occasional lightning is also possible tonight across the northern
Mid-Atlantic coast into southern New England near the deepening
surface low and strong warm-air advection.
.PREV DISCUSSION… /ISSUED 1026 AM CST Sun Dec 01 2019/
…Coastal Southeast States/Florida…
Showers/isolated thunderstorms continue to accompany a cold front as
it progresses east-southeastward toward the coastal Southeast and
across northern Florida. A relatively moist/modestly unstable air
mass precedes the front across northern Florida into southeast
Georgia. However, weak mid-level lapse rates will likely temper
updraft vigor, with a tendency for convection to remain anafrontal
coincident with a veering of surface winds ahead of the front. While
a couple of thunderstorm-related stronger wind gusts could occur in
areas such as coastal southeast Georgia/far northeast Florida, the
overall severe potential should remain rather limited.
…Eastern Ohio to Pennsylvania/West Virginia border…
Isolated thunderstorms will likely develop this afternoon,
particularly within a narrow warm sector near the surface low and
nearby occluded front. Low-level moisture will remain limited (40s F
surface dewpoints), but steep low/mid-level lapse rates could allow
for a couple of stronger low-topped surface-based storms this
afternoon. Given ambient vorticity near the low and adequate
low-level CAPE, small hail, a stronger wind gust and/or a funnel
could occur, but the overall potential for a severe-caliber storm is
still expected to remain very low.