635
FXUS62 KCAE 031729
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
129 PM EDT Wed Sep 3 2025

.SYNOPSIS...
Temperatures warming to near normal through Thursday ahead of a
diffuse cold front where it should remain mostly dry. Above
average temperatures Friday and Saturday before a stronger front
moves into the area late this weekend leading to chances for
rain into early next week.

&&

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

- A few showers across the Upstate and NC will weaken as dry
  high pressure remains in place for our area.

A subtle shortwave embedded within the broad upper level trough
is helping produce some showers lee of the Appalachians, along
with some more widespread cloud cover; this shortwave is
apparent in the water vapor imagery, despite surface high
pressure in place. Not much of an impact is expected even if any
of these showers sneak into the western-northern Midlands since
PWAT`s are still only around 1.0", instability is effectively
zero despite steep lapse rates, and surface dew points are in
the 50`s. So some virga would be more likely than any actual
showers. Regardless, some additional cloud cover is expected
across the northern-western Midlands this afternoon as a result.
Temps are running a bit below guidance, partially due to this
cloud cover, with high temps likely remaining in the low 80`s
and the 70`s in the northern Midlands. The high pressure center
will begin to lift north and east of our area later tonight as
after this shortwaves kicks through, allowing southerly
component flow and moisture to slowly return into Thursday.

&&

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

- Warming trend continues through the end of the week while
  staying mostly dry.

500mb heights remain neutral through Thursday as a weak
shortwave may pivot toward the upstate through the day before
modest height rises are expected into Friday. Low level flow
turns out of the southwest through the short term period,
leading to increased warm advection with temperatures that are
near normal Thursday then above normal into Friday. This flow
should also increase moisture some as PWAT`s raise to between
1.3-1.5", highest in the upstate and into the northern FA on
Thursday before this axis shifts south Friday. As the now
occluded surface low in southern Canada continues to slowly
retrograde westward Thursday, a weak surface front pushes into
the Tennessee Valley, but majority of model guidance is showing
this front becoming increasingly diffuse near the Appalachian
mountains. With this front and a weak shortwave moving across
the mountains and the upstate, showers and some storms are
expected to develop in the upstate during the afternoon
Thursday. High res models and the deterministic NAM, GFS, and
ECMWF keep this activity north of the CWA with forecast
soundings indicating plenty of dry air aloft. While a mostly dry
day is expected, a shift a bit more south in the shortwave
could lead to a shower or weak storm sneaking into our northern
tier of counties. The 500 mb height rises, general lack of
forcing, and substantial dry air aloft should bring a dry day
Friday as well.

&&

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

- Above average temperatures Saturday before cooler conditions
  set in to start next week.

- Cold front moves through late Saturday and into Sunday,
  leading to a slight chance to chance for showers and some
  thunderstorms.

- Slight chances for rain carry into the early week.

There is not much change in the extended forecast outside of
PoP`s that have slightly increased for Sunday. There remains
high confidence in above normal temperatures Saturday as modest
height rises and warm advection pushes into the area, along with
increasing moisture with PWAT`s now raising near to just above
1.5". This should lead to hot and humid conditions Saturday, but
with dry weather likely prevailing as the main cold front
remains to our NW most of the day. This front then is expected
to near the FA late Saturday before working through the area on
Sunday. There remains some discrepancy amongst deterministic
guidance on the depth of moisture and strength in moisture
transport ahead of the front, but in general at least slight
chances for showers and some thunderstorms will exist Sunday
afternoon as PWAT`s approach 115-120% of normal (per GEFS and
EC Ensemble mean solutions) with decent convergence along the
front. The thunderstorm potential appears to have increased some
with majority of EC Ensemble members showing MUCAPE over 500
J/kg, but GEFS members are not as excited so some uncertainty
remains, especially with the exact timing of the front. At
least a slight chance for showers and storms seems reasonable at
this time.

Heading into the early week, temperatures cool back below
normal as strong high pressure (1-1.5 standard deviations above
normal) moves into the Mid Atlantic and the upper East Coast.
This should turn low level flow increasingly out of the
northeast, bringing a cooler near surface air mass. Flow aloft
looks to be a bit more southwesterly and thus increased moisture
aloft over-riding this cooler low level airmass could bring
slight chances for showers into the early week. It could also be
a bit breezy at times early next week as both the ECMWF and GFS
show some inverted troughing off the coast of the Carolina`s
leading to an increased pressure gradient.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR conditions likely through period.

A weak trough is pushing to our north this afternoon, producing
some mid-level cloud cover north of the TAF sites. TAF sites
should remain mostly clear this afternoon as high pressure
remains in place. Winds will also remain light and generally
variable throughout the TAF period. Tonight, some shallow
moisture may lead to brief periods of MIFG fog, primarily at
AGS and CAE. Given the relative lack of moisture, confidence is
too low for any lower than VFR TAF mentions.

EXTENDED AVIATION OUTLOOK...Showers possible late Thursday could
yield some restrictions but confidence in impacts is low.

&&

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

&&

$$