634
FXUS62 KGSP 210114
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
914 PM EDT Mon May 20 2024

.SYNOPSIS...
Warm high pressure will persist across the region through the
middle of the week. A cold front approaches from the northwest on
Thursday, bringing a chance of showers and storms mainly to the
mountains. The front will stall over the area Friday, keeping rain
chances through weekend and into early next week.

&&

.NEAR TERM /THROUGH TUESDAY/...
As of 900 PM EDT Monday: Isolated showers linger across portions
of the North Carolina mountains this evening and the lightning
potential looks to be over. Thus, the HWO mention for lightning
through the evening was removed. Lowered PoPs to slight chance (15%-
20%) over the next few hours, with dry conditions returning
for the mountain zones around midnight. Stratocu has increased in
coverage across the NC/GA/SC mountains, the NC Foothills, and the
northern SC Upstate the last few hours. Went ahead and blended in
some cloudier guidance to bump up cloud cover across these areas
through the overnight hours.

Otherwise, persistence looks like a really good forecast over the
next 24 hours as the salient features don`t change much. We continue
to enjoy a positively-tilted mid/upper ridge that supports weak high
pressure to our northeast. As a result, expect another round of
mountain valley low stratus/fog late tonight, with some locally
dense. Once that mixes out in the middle-part of the morning, the
day should be quiet again east of the mtns, but ridgetop showers can
be expected in the mid/late afternoon. High temps will nudge upward
a bit, maybe a category above normal Tuesday afternoon.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
As of 200 PM EDT Monday: An upper ridge axis starts out the period
over the area. The axis slowly moves east and becomes suppressed by
the end of the period as some weak short waves top move through the
flow. The result Is a very low chance of diurnal mountain convection
Wednesday, then a better chance on Thursday as the cap erodes
allowing sbCAPE to be realized. For now, chance PoP on Thursday is
limited to the mountains and I-40 corridor, with isolated PoP south
of there to the I-85 corridor. Highs will be well above normal both
days, making a run at 90 for the CLT Metro, Upstate, and NE GA. Lows
5 to 10 degrees above normal as well.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
As of 215 PM EDT Monday: An active pattern returns for this period
as a series of short waves move east across the area. These will
push a series of low pressure/frontal systems across the area as
well. Expect good to numerous, mainly diurnal, convective coverage
each day, with the highest PoP favoring the mountains. Still to
early to be certain on the severe storm chances given the potential
for limited instability, even though forcing and shear will be
decent. Heavy rain potential may eventually creep up as well,
especially if the better coverage hits the same areas day after day.
Highs will drop a few degrees on Friday then remain nearly steady
through the period. Lows rise a few degrees then remain nearly
steady.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Stratocu has expanded in coverage across the
mountains, the northern SC Upstate, and the NC Foothills this
evening. This is mainly impacting the SC Upstate terminals, KAVL,
and KHKY as KCLT has clear skies in place. Dry conditions are noted
east of the mountains, lingering through the remainder of the 00Z
TAF period. Isolated showers continue over portions of the North
Carolina mountains this evening, mainly impacting KAVL. Thus, have
VCSH mentioned through 03Z at the terminal. Mountain valley fog
should develop again overnight into daybreak Tuesday, mainly
impacting KAVL. Went with prevailing IFR vsbys by 0700Z with a TEMPO
for LIFR vsbys and cigs from 0900Z-1200Z. Patchy fog could briefly
develop again at KHKY around daybreak, so maintained the VFR fog
mention. Fog should mix out shortly after sunrise. Another round of
VFR cumulus should develop Tuesday afternoon and evening, although
KAVL may see low-end MVFR cumulus develop. KAVL will likely see
another round of isolated SHRA/TSRA late Tuesday afternoon into
early Tuesday evening, so have VCSH at the terminal starting at
2100Z. Winds are expected to be calm this evening into daybreak
Tuesday, picking up out of the S/SE by Tuesday afternoon.

Outlook: High pressure remains over the terminals through Wednesday
but isolated mountaintop convection is expected each afternoon.
Showers and thunderstorms, along with restrictions, may return with
a cold front late Thursday into Friday.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$

SYNOPSIS...DEO
NEAR TERM...AR/PM
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...AR