524
FXUS62 KCAE 190630
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
230 AM EDT Thu Sep 19 2024

.SYNOPSIS...
Showers and thunderstorms will be possible today, favored in
the eastern Midlands. Moisture is expected to decrease Friday.
High pressure will build into the area from New England over the
weekend into early next week with dry and seasonable
temperatures expected.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Message(s):

- Isolated to scattered showers and thunderstorms today

The upper low will open up into a trough as it shifts eastward
today. The axis of the trough will move offshore with drier air
moving into the region through light N winds. Despite lower PWAT
values than the previous day, atmospheric moisture remains
relatively high in the eastern Midlands and Lowcountry with PWAT
values from 1.6 to 1.7 inches. As convection develops in the
afternoon, aided by shortwave energy rounding the base of the
trough, development will be favored in the eastern Midlands.
Drier air to the west will work to inhibit showers. Overall, the
direr airmass will keep showers and thunderstorms isolated to
widely scattered. Convection will diminish in the evening with
loss of heating, although a weak shortwave could support an
isolated, lingering shower into the overnight period. Mean
sbCAPE values from the HREF are lower than 750 J/kg suggesting
instability may be too limited for any severe threat. Highs will
be in the low to mid 80s with lows overnight in the mid 60s.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
Key Message(s):

- Drier weather for Friday.
- Seasonable temperatures.

Friday and Friday night...Low-level moisture remains high
through the day especially in the east. Precipitable water only
decreases slightly. There appears to be a weak cold
front/moisture boundary moving south from eastern North Carolina
in the afternoon. Latest GFS/Nam suggest a few showers may
develop in the east again as another short wave moves through
upper trough, but appears more focused in the Coastal Plain
potentially aided by sea breeze convergence. The NBM pops are
quite low and mean CAPE lower than Thursday. Any convection
should be isolated. Temperatures a little warmer than Thursday.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
Key Message(s):

-Drier into early next week with warming trend over the weekend

The ensembles continue to be in good agreement. Upper trough off
the east coast with upper ridge over the southern Plains
building east but flattening with time. Surface high ridging
down the Eastern Seaboard. Low-level moisture remains high,
high level moisture may increase by early Monday as the ridge
flattens. Ensemble qpf probabilities > 0.1 inch only 10-20 %
Sunday/Monday. NBM pops very low at this time so will continue
dry forecast.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
Lingering low-level moisture over the region will promote
patchy low clouds and fog over the terminals this morning. Given
the patchy nature of the cloud decks it`s difficult to
determine how prolonged any IFR or possibly LIFR conditions
would last. With some drier air working into the area, fog could
develop as clouds break up but would be localized. It is
shaping up to be a messy forecast through the morning with low
confidence in restrictions and their duration.

Any possible restrictions would begin mixing out after sunrise
but MVFR conditions could persist into the mid to late morning
before all sites return to VFR. Winds will generally be light
and out of the north. Convective coverage today should be more
limited than the previous day, with highest rain chances in the
eastern Midlands near OGB. At this point, confidence is not high
enough to include in the TAFs but showers and thunderstorms
will be possible again. Any convection will diminish during the
evening hours. Drier air working into the region should reduce
the chances of stratus like we`ve seen the previous nights. But
shallow moisture lingering over the area could support patchy
fog around sunrise.

Extended Aviation Outlook...Drier air over the region will
limit the chance of restrictions through the weekend before
moisture begins to increase early next week.

&&

.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.

&&

$$