Sumter, South Carolina 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

363
FXUS62 KCAE 161118
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
618 AM EST Tue Dec 16 2025

.SYNOPSIS...
Weak upper ridging will allow for a warming trend into the mid-
week period. The next chance of rain arrives Thursday into
Thursday night as a cold front sweeps through the region.

&&

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

- Abnormally cold temperatures this morning

Temperatures will be well below normal to start the day with
morning lows in the low to mid 20s and a few spots in the upper
teens. Non-impactful weather for the remainder of the period.
High pressure shifts offshore promoting SW flow and warmer
temperatures than yesterday. Highs will be in the low to mid
50s. High cloud cover increases tonight helping to keep lows
closer to normal with values near freezing.

&&

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

- Temperatures warming ahead of a cold front.

- Rain chances continue to trend upwards Thursday into Thursday
night.

By Wednesday, high pressure expected to be offshore with weak upper
ridging in place. Temperatures will continue to trend warmer with
increasing moisture as well leading to more cloud coverage. PWATs
remain limited through the day and as a result rain is not expected.
HREF has high probability (greater than 70 percent) of PWATs
remaining less than three quarters of an inch through the day. Highs
expected to be in the upper 50s to low 60s with overnight lows
generally in the low to mid 40s.

Thursday continues to trend wetter with ensemble mean PWATs
continuing to increase with each run. NAEFS mean now indicates PWATs
above the 90th percentile across the area. Isentropic lift
strengthens during the day with a southern stream shortwave that has
trended stronger. This will lead to moisture convergence across the
area with scattered showers possible. Potential for temperatures to
remain somewhat constant with rain and clouds but warm advection
likely strengthens late in the day ahead of the cold front. GEFS
mean still indicates the most likely timing for PWATs to increase
above an inch for much of the area to be Thursday evening and
blended guidance continues to favor highest pops in the evening to
overnight hours, likely owing to stronger forcing from the cold
front. While blended guidance indicates around 80% chances of total
precip less than a half inch, increasing skewness towards some
higher amounts in the GEFS and EC ensemble distributions.
Regardless, hazardous weather is not expected and with most of the
area abnormally dry, any rainfall would be beneficial. Drier air
expected behind the cold front Thursday night into Friday morning.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Key Message(s):

- Near to above normal temperatures expected.

High pressure moves in behind the front for the end of the week with
a high probability of a much drier air mass and ensemble means
indicate PWATs 50 percent of normal or less. Not a particularly cold
air mass expected behind the front with ensemble means showing near
normal 850mb temperatures and thus blended guidance favoring near
normal temperatures. Gradual moisture increase likely late in the
weekend with temperatures trending warmer. While moisture is likely
to increase, forcing appears limited with low chances for rain
through the extended period.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
VFR conditions through the TAF period.

No impacts expected in the 24 hour TAF period. Winds will be
calm during the overnight hours with light SW winds during the
day as high pressure shifts offshore. The very dry air mass
will prevent restrictions with just a few high clouds moving in
tonight.

EXTENDED AVIATION OUTLOOK...The next chance for widespread
restrictions will be mid-week as moisture increases over the
Southeast. This will lead to potential early morning
restrictions and increasing rain chances.

&&

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

&&

$$