National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KCAE 210715
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
315 AM EDT Wed Aug 21 2019

.SYNOPSIS...
High pressure in the Atlantic will direct a moist south
flow into the forecast area through the rest of the workweek. Then,
an upper-level low will cross the Northeast and its associated
cold front will push into the forecast area over the weekend.
The pattern supports high chance to likely probabilities of
showers and thunderstorms this weekend. The front may linger
over the forecast area early next week, keeping a chance of
showers in the forecast.

&&

.NEAR TERM /THROUGH TONIGHT/...
The upper trough that helped support showers and thunderstorms
during the early morning hours will be north of the forecast area
today and tonight. There will be h5 ridging and h85 westerly flow in
its wake. The main thunderstorm support will be strong heating and
weak convergence into a lee trough this afternoon. The high-
resolution models suggest little thunderstorm coverage. We continued
the forecast of just chance pops. Moderate instability indicates a
few of the thunderstorms could possibly contain strong wind. The
thunderstorm chance should further diminish this evening with the
loss of heating. The temperature guidance was close with highs
mainly in the lower 90s and lows in the lower 70s. Expect peak heat
index values around 100 this afternoon.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
Flatter upper level flow is expected during the day Thursday,
but a lee surface trough will be in the area. Shortwave energy
will then approach from the north during the evening, and
scattered convection will again be possible.

Temperatures will be seasonal with highs in the low 90s and lows
in the low 70s.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
On Friday, an upper level trough will swing through the Northeast
with the associated cold front pushing into North Carolina. Scattered
convection will therefore be possible on Friday, but there is a much
better chance of rain on Saturday and Sunday as the front stalls over
the area. With PWAT values above 2 inches and expected high convective
coverage, there will be a threat of heavy rainfall and flooding. The
front will be dissipating on Monday, but high pressure off the coast
will cause onshore flow which will then continue to fuel convection.
Onshore flow is expected to persist on Tuesday, so at least diurnal
convection can be expected. Temperatures will cool somewhat over
the weekend and into the beginning of next week with highs mainly
in the 80s.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
Expect mainly VFR conditions during the 24-hour TAF period but
there will be a chance of thunderstorms.

The upper trough that helped support showers and thunderstorms
during the early morning hours will be north of the forecast area
today and tonight. There will be h5 ridging and h85 westerly flow in
its wake. The main thunderstorm support will be strong heating and
weak convergence into a lee trough this afternoon. The high-
resolution models suggest little thunderstorm coverage. The
thunderstorm chance was too low to include in the terminal forecast
at this time. Moderate instability indicates a few of the
thunderstorms could possibly contain strong wind. The thunderstorm
chance should further diminish this evening with the loss of
heating. There is a diminished fog risk because of weak instability
and mixing. The NAM and GFS MOS and most SREF members maintain VFR
conditions.

EXTENDED AVIATION OUTLOOK...Widespread showers or thunderstorms may
occur Saturday and Sunday associated with a front moving into the
region. Otherwise, there may be stratus and fog during the early
morning hours with scattered mainly afternoon and evening
thunderstorms.

&&

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

&&

$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99