424
FXUS62 KCAE 210707
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
307 AM EDT Fri Jun 21 2024

.SYNOPSIS...
Moisture will increase across the area over the weekend as low
pressure approaches from offshore. This will lead to mainly
scattered diurnally driven showers and thunderstorms focused
in the southeast Midlands and CSRA through Sunday. A weak cold
front will move into the area late Monday and possibly enhance
diurnally driven showers and thunderstorms through midweek. Well
above normal temperatures are expected by Sunday into early
next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
Skies are clear across the forecast area tonight as high pressure
remains in control. Some increase in cloudiness from the east is
possible as an area of low pressure, Invest 92L, continues to move
west towards the Georgia and Florida coasts. Temperatures are on
track to fall into the mid to upper 60s.

Clouds are expected to increase today as Invest 92L approaches. The
biggest impact of this system in our forecast area will be a notable
increase in PWATs through the day with a chance of showers and
perhaps a thunderstorm or two during the afternoon and evening
hours, mainly south and east of I-20. Our northern and western
counties should see continued warm and dry conditions today with
scattered cumulus, a scenario suggested by modeled soundings at
KCLT. Temperatures will be coolest today closer to the coast where
the most robust cloud cover will be. Highs across the region should
end up in the mid-80s to lower 90s. Skies should clear out after
sunset with any rain chances quickly diminishing. Having said that,
the increased moisture could result in areas of low clouds and/or
patchy fog developing towards daybreak Saturday. Low temperatures
tonight will be around 70 degrees.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
KEY MESSAGES:

- Tropical wave/low pressure moving inland south of the area.
- Increasing chance for afternoon and evening thunderstorms.
- Above normal temperatures expected.

Saturday and Saturday night...Upper level ridging, centered to
the west of the area extends into the area. The westward moving
tropical wave/area of low pressure should be moving inland
mainly south of the area across coastal GA into Florida
Saturday. Precipitable water increases to 1.80 to near 2.00
inches (around 120 percent of normal) in the lower Savannah
river area and southeast Midlands Saturday afternoon. The air
mass is a little drier in the north Midlands and SC Piedmont.
Warm advection and moisture flux focused in the southeast
Midlands. Instability overall appears limited. Showers and
thunderstorms possibly enhanced along a sea breeze front, so
have chance pops in the southeast Midlands. Lower chance of
showers and thunderstorms to the northwest as mid level capping
should be stronger/moisture possibly more limited. Temperatures
slightly above normal in the low to mid 90s for high temps.

Sunday and Sunday night...Moisture appears to increase across
the area and the upper ridge retrogrades a bit to the west.
Perhaps some weak short wave troughs will rotate around ridge to
provide lift. Still think higher chance of afternoon and evening
thunderstorms remains across the CSRA and southeast Midlands
enhanced by sea breeze with capping stronger to the northwest.
Instability remains weak but stronger near the coast. 850mb
temps warm a degree or two so temps should be a little warmer
with most areas rising into the mid 90s. Heat index values in
the 100-105 degree range. Muggy overnight temps in the low to
mid 70s.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
KEY MESSAGES:

- Heat builds into next week with heat indices remaining 100.
  Warmest day appears to be Wednesday with heat index values
  near 105 or a little higher.
- Typical scattered afternoon/evening thunderstorms are
  expected.

The NAEFS and ECMWF EFI point to temperatures above normal, but
not significantly, with the warmest day Wednesday. Early in the
week, an upper trough over New England with trough axis along
the coast. Area in northwest flow aloft with rather strong
downslope flow Monday. Upper ridge is now centered in the
southern Plains to Desert southwest. A weakening cold front will
be approaching from the north late Monday then stall near the
area or south of the area Tuesday. Scattered mainly diurnally
driven showers and thunderstorms Monday, lower pops Tuesday as
drier air moves in behind the front. Ensembles showing upper
trough in the Tennessee Valley moving into the southeast
late Wednesday into Thursday. This trough should drive a weak
cold front toward the area. Moisture appears to increase again
with ensemble precipitable water > 1.5 inches probabilities in
the 80-90 percent range by Thursday. Overall instability weak to
moderate mid week and deep shear should increase. Convergence
along front support at least scattered showers and
thunderstorms. Temps should cool a bit by Thursday.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
Skies are currently clear at the terminals tonight as high pressure
remains in control of our weather. Winds will be calm or light out
of the east. An area of low pressure to our southeast will approach
the Georgia and Florida coasts today, likely resulting in scattered
cumulus and/or stratocumulus later this morning. A few showers or
thunderstorms are possible by the afternoon but overall confidence
is low. Have added VCSH to OGB which is the most likely terminal to
see showers and perhaps brief restrictions. Will need to monitor
trends and see if the rain chances extend further north and west to
the other terminals. Any lingering showers should quickly diminish
with the loss of daytime heating giving way to clear skies. Easterly
winds are likely to continue through the TAF period.

EXTENDED AVIATION OUTLOOK...Brief restrictions possible in
isolated to scattered afternoon and evening thunderstorms on
Saturday with increasing chances Sunday through Tuesday.

&&

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

&&

$$