102
FXUS62 KGSP 201817
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
217 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 213 PM Monday: Still awaiting deep convection initiation over
the mtns early this afternoon, but no reason to think that it won`t
get going on some of the ridgetops in the next hour. The CAMs are
fairly consistent in concentrating their efforts over the Balsams
and the headwaters of the French Broad R. No significant changes
were made to the precip chances, or to the high temps either.

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 /18Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Mountain valley fog/stratus will last
thru 13-14z at KAVL. Patchy/variable fog also being reported
in parts of the Piedmont, mainly near rivers, but this likely
will lift/dissipate in the first hr of the TAF period. NE winds
will continue until early afternoon owing to weak high pressure
to our north, with diurnal cu forming at MVFR to low VFR level
but probably not causing cigs. Winds go SE with aftn mixing and
southward migration of sfc high. Ridgetop SHRA or even TSRA are
possible but too isolated to mention at KAVL. SE flow tonight
will produce VFR to MVFR stratus in the foothills. KAVL likely to
see valley fog develop again hence prevailing IFR mention after
07z. River valley fog appears possible, most likely affecting KHKY
which gets MVFR late.

Outlook: High pressure remains dominant over our area thru
Wed, but isolated mountaintop convection still expected each
afternoon. Precip and restrictions possible with next front arriving
late Thu or Fri.

&&

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

&&

$$

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