509
FXUS62 KCAE 101810
AFDCAE

Area Forecast Discussion
National Weather Service Columbia SC
210 PM EDT Fri May 10 2024

.SYNOPSIS...
Scattered showers and thunderstorms are possible again today as
a cold front approaches and moves through the area today. High
pressure then moves in for the weekend, bringing dry weather.
The high moves offshore Monday and increasing moisture supports
showers and thunderstorms returning for next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
10/15Z analysis places a surface low in the upstate with frontal
boundaries extending northeast and southwest. Mainly scattered to
broken high clouds across the region in wake of a significant MCS
departing offshore to our southeast. Additional convection continues
across the FL Panhandle. Temperatures across the Midlands and CSRA
have risen into the mid and upper 70s with dewpoints in the mid and
upper 60s ahead of the approaching front.

While things are quiet at the moment, an approaching shortwave will
enhance dynamics and generate showers and thunderstorms. A few
showers have already initiated along the frontal boundary across the
upstate. Latest CAM solutions including the last several HRRR runs
and the WoFs are consistently depicting a line of storms forming
particularly from the northeast CWA southwest through the Columbia
area and pushing east. There is less confidence that another line
will follow it, but in general areas northeast of Columbia look to
be the most favorable for strong to severe storms.

Conditions ahead of the front are expected to support at least a
slight risk for severe thunderstorms, including large hail. The
overall tornado threat appears to be low. Daytime heating combined
with plenty of moisture will generate SBCAPE of 1500-2000 J/kg along
with 40-60 kts of 0-6km bulk shear. Area soundings also depict ample
CAPE in the hail growth zone and strong unidirectional shear. A
severe thunderstorm watch is now in effect for portions of the CWA
through 9 PM this evening.

With the frontal passage this evening, skies are expected to clear
quickly with winds becoming northwesterly. As such, dewpoints should
fall through the 50s into the upper 40s in some locations and PW
values drop below 1". Cold air advection will usher in cooler lows
than we have seen as of late, generally in the 50s. Winds will
remain somewhat elevated overnight though, so it appears any fog
threat will be minimal.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
We finally made it! A much deserved break in the weather is expected
this weekend as troughing, upper level convergence, and surface high
pressure settle into the region. Guidance is in wonderful agreement
in the forecast for Saturday and Sunday. Partly cloudy skies are
expected on Saturday as a reinforcing shortwave dives through the
Mid-Atlantic, with highs in the upper 70s. Lows will be in the 50s
under clear skies Saturday night. Sunday should be a bit warmer with
some downslope flow expected as high pressure shifts through the
area. Highs should be in the 80s with lows in the upper 50s.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Fairly high confidence in the pattern that is expected to unfold
next week. A progressive and meridional pattern is shown by LREF
members by Monday and this should take us through the end of next
week. Slow, lowish amplitude upper level trough is expected to be
centered across the central Plains by Monday morning, with a ridge
axis shifting across our FA through the day. Surface high pressure
should still be in place but is expected to shift offshore by Monday
night, with moisture and isentropic lift increasing through the day.
Rain is likely by Monday night, with each group of ensembles in the
LREF showing ~70-80% of members with rain chances by Monday night.
Surface low should slowly push eastward on Tuesday, settling over
the OH Valley. Strong westerly and southwesterly flow is shown by
both operational models and LREF members. While operational models
are unsure about convective potential, the overall synoptic setup is
one that tends to favor at least thunderstorms across the FA. LREF
members generally show decent probabilities (25-40%) of sufficient
CAPE and shear to support potential strong storms. So we`ll need to
keep a close eye on model trends over the next couple of days.

Rain chances look to peak Tuesday evening, with the trough axis
shifting the best lift and surface low to our east on Wednesday. The
break looks short, though, as another shortwave is expected to dig
into the south-central Plains. A ridge axis will likely settle in
over the region by Wed/Thur, with significant uncertainty regarding
the pattern thereafter emerging. The shortwave trough that digs into
the southern plains looks like it could be significant, but timing
and amplitude issues abound amongst LREF members and operational
models. For now, will keep the NBM as is given the significant
uncertainty in the long term. Temps should be seasonal or slightly
below normal in this period given the repeated shots of rain and
potential cloud coverage. Highs will likely be in the upper 70s to
mid 80s with lows in the 60s.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Expect a period of VFR conditions this afternoon. A line of showers
and thunderstorms is then expected to develop and may cause some
restrictions at the terminals this afternoon and early this evening.

Mainly high clouds remain across the region this afternoon with
continued thinning. Another round of scattered showers and storms
are forecast to move through the region during the 18z-00z
timeframe. Storms to the north will progress southeast this
afternoon. Most of this activity looks to remain northeast of AGS
and DNL, but have included VCTS in case development is slightly
further southwest. Otherwise, the threat is covered at the terminals
with TEMPO groups and there is potential for gusty winds in excess
of 30 kts and brief CIG/VSBY restrictions. Thereafter into tonight,
drier air and clear skies return along with VFR conditions.

Breezy west to southwest winds 10-15 kts with gusts to 25 kts
expected through about 11/00z before shifting to northwest. Speeds
remain around 4-7 kts overnight into Friday morning.

EXTENDED AVIATION OUTLOOK...No restrictions late tonight through
this weekend. Showers and thunderstorms are possible Monday and
Tuesday along with associated restrictions.

&&

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

&&

$$