117
FXUS62 KCAE 170848
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
448 AM EDT Sat May 17 2025

.SYNOPSIS...
The weekend looks warm and humid with a few afternoon and
evening showers and thunderstorms possible. The next significant
chance of rain comes during the middle of next week with warm
temperatures persisting. Temperatures are forecast to drop off
for late in the week ahead.

&&

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

- A few showers or thunderstorms are possible this morning, while
temperatures are expected to remain above normal this afternoon.

We continue to watch a line of severe convection moving through TN
and into western NC/northwestern SC this morning. The line of
thunderstorms should make steady progress toward the southeast and
near our western CWA line. However, mid level support for
thunderstorms is much lower in our area by sunrise, so expect just
remnants to approach the northwestern CWA with possibly a few
showers and an isolated thunderstorm by daybreak. Temperatures are
going to be mild this morning, only in the mid 70s.

Guidance continues to show a weak cold front passing through the
region today. The most recent CAM runs indicate the decaying line
pushing through the area this morning, then the potential for some
redevelopment across the CSRA and into the eastern Midlands this
afternoon. SPC maintains a Marginal (1/5) risk for severe weather in
their latest Day 1 SWO, mainly for the threat of damaging
thunderstorm winds. That said, a few model soundings are showing in
excess of 1000 J/kg of SBCAPE already in play by late this morning,
likely influenced by our mild temperatures and dewpoints in the mid
to upper 60s as we start warming for the day. While I think overall
coverage will be low, I can`t rule out one or two severe
thunderstorms through the day.

It will be breezy at times across the forecast area this afternoon
along and ahead of the front with a tightened surface pressure
gradient. Temperatures should reach the upper 80s to low 90s for
highs this afternoon, though any precip and the continuous cirrus
may slightly impact these values. Skies should begin clearing a bit
by tonight with lows around 70 degrees.

&&

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

- Continued warm, with a slight reprieve of humidity on Sunday.
- Chances for afternoon showers and thunderstorms each
  afternoon.

Sunday and Sunday night: Upper low continues to trek across the
Great Lakes into New England, resulting in a transition from
zonal flow aloft to start the day to more northwesterly. This
transition is forecast to bring slightly drier air into the area
as dew points are anticipated to be in the lower to mid 60s in
the afternoon. The front that passed through the area is
expected to be just south of the area for the day, but remain
close enough that some afternoon showers and thunderstorms are
possible in the southern portion of the forecast area. The HREF
mean is indicating surface based CAPE in the 500-1000 J/kg range
and 0-6 km bulk shear around 40 kts in that area, which is
sufficient enough to produce a stronger storm should
thunderstorms develop. Afternoon highs are expected to be near
90 again with some variation dependent on convection.

Monday and Monday night: The upper low in New England continues
to track eastward Monday, allowing for a ridge to build
overhead. This ridge should allow for temperatures to be
slightly warmer than Sunday. A weak shortwave is forecast to
move across the area during the afternoon and the frontal
boundary to our south is forecast to lift northward some. As a
result, there is mainly a slight chance for afternoon showers
and thunderstorms once again and the humidity is forecast to
creep back up as dew points return to around 70.

&&

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

- Warm and humid conditions continue into midweek, with showers
  and thunderstorms possible each afternoon.
- Relatively cooler and drier air filters in for the end of the
  work week.

Upper ridging begins to shift eastward into midweek as an upper
low and associated trough dig into the central CONUS. This is
expected to aid in lifting the frontal boundary northward,
keeping temperatures above normal and dew points on the higher
side for this time of year. This along with embedded upper
shortwaves are forecast to bring chances of shower or
thunderstorm activity. As the upper trough moves east, an
associated cold front is forecast to move toward and through the
forecast area midweek, which brings a higher chance of
showers/storms to the region. Latest guidance indicates
temperatures get closer to normal after the front passes and a
relief from the humidity is anticipated. Chances for
precipitation are also forecast to decrease for the end of the
week.

&&

.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/... Mainly VFR
Conditions Expected through the TAF Period.

Plenty of high level cloudiness will be streaming across the
region overnight and through much of the day on Saturday. This
should be the primary cloud group for much of the period at all
taf locations. Exception may be at ags/dnl sites Saturday
morning shortly after sunrise, where a brief ceiling around 5kft
may be found as diminishing area of showers moves in from the
northwest ahead of an approaching cold front. Most guidance is
indicating that showers will be all but gone as these clouds
push through the CSRA, and will no longer include any vcsh at
those locations due to low confidence. Otherwise, southwesterly
winds should be stronger at the TAF sites on Saturday as the
front passes through the region, with some wind gusts around 25
knots at all taf locations during the afternoon hours.

EXTENDED AVIATION OUTLOOK... Mainly VFR conditions expected
through the period barring low end chances for showers and
thunderstorm each afternoon which could cause brief
restrictions.

&&

.HYDROLOGY...
Most rivers are either near crest, or have already crested and
are falling. However, periodic releases along the Broad and
Saluda Rivers are causing fluctuations downstream in the
Congaree. The gage at Columbia will likely stay below advisory
levels, but could briefly rise to advisory level as these
fluctuations occur. Downstream the gage at Carolina Eastman is
decreasing quickly and likely will drop below flood stage, but
there`s a good chance (50%) that the levels rise above flood
stage once again. Expect river flooding to continue along the
Congaree River through Gadsen, and along both the North and
South forks of the Edisto River. River levels will generally
continue to fall through the weekend.

&&

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

&&

$$