582
FXUS62 KGSP 202212
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
612 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 600 PM EDT Monday: Finally seeing some isolated showers
develop across the mountains this evening. No lightning is currently
present in this activity, but thunder will remain possible through
sunset. Cumulus that developed this afternoon is dwindling in
coverage since it`s past peak heating. Thicker cloud cover continues
across portions of the North Carolina mountains this evening. Main
change needed was the tweaking of PoPs, cloud cover, and winds
through the near term period. Otherwise, the forecast remains on
track.

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 /22Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Diurnal cu continue this evening at low VFR
levels. Winds are mainly E/SE thanks to both mixing and the
southward migration of sfc high. Ridgetop SHRA or even TSRA are
possible through early this evening, but have VCSH mentioned at KAVL
through this evening. SE flow tonight will produce VFR to MVFR
stratus in the foothills. KAVL is likely to see valley fog develop
again hence prevailing IFR mention after 06Z. River valley fog
appears possible, most likely affecting KHKY which gets MVFR around
09Z.

Outlook: High pressure remains dominant over our area through
Wednesday, but isolated mountaintop convection is still expected
each afternoon. Precip and restrictions are both possible with next
frontal system which should arrive late Thursday or Friday.

&&

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

&&

$$

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