730
FXUS62 KGSP 200133
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
933 PM EDT Sat Apr 19 2025

.SYNOPSIS...
Dry high pressure remains in place this weekend. A cold front
arrives Monday night and stalls across the area on Tuesday. Daily
showers and thunderstorms will develop through most of the week as a
result.

&&

.NEAR TERM /THROUGH SUNDAY/...
As of 930 PM EDT Saturday: Main change needed this evening was
increasing dewpoints slightly over the next several hours as obs
were still running a bit higher than the forecast. No other major
changes were needed. Cirrus continue streaming across the forecast
area this evening. Upper cloud cover will remain over the region
through the near term.

Otherwise, upper ridge off the Southeast Coast with Bermuda high in
place at the surface will continue to bring WAA to the area with
temperatures expected to run 10-15 degrees above normal overnight.
As we move into Easter Sunday, despite the upper ridge continuing to
dominate, a bit of lee troughing may develop as a mid-level low
approaches from the west and starts to lift over the ridge. Moisture
advection especially at 850mb should allow more afternoon cloudiness
to develop in almost a summertime Cu pattern as temperatures rise to
similar levels as today, 10+ degrees above seasonal normals.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
As of 151 PM EDT Saturday...

Key Messages:

1) A weakening frontal system will arrive Monday night and result
in increasing rain chances from Tuesday morning onward.

2) Thunderstorms are expected on Tuesday afternoon, but with little
risk of severe weather.

3) Well above normal temperatures on Monday will moderate somewhat,
but remain above normal on Tuesday.

No major changes to the short term forecast.  A deep and
increasingly tilted upper ridge will begin to break down on Monday
as a compact shortwave rides up and over it, skirting its way
across the upper Ohio Valley and into New England by the latter
part of the period.  Its surface reflection will dig across the
Tennessee Valley in the form of a weakening cold front, still
progged to arrive in the Carolinas by Monday night into early
Tuesday.  As the shortwave lifts north, the frontal circulation
will begin breaking down, and by the time associated precip gets
going Tuesday afternoon, it will be stagnating.  Finding itself
oriented increasingly parallel to flattening upper flow, it`ll be
marooned roughly along the I-85 corridor by late Tuesday.

Despite the front`s lack of vigor, its position will nonetheless
provide a trigger for convective activity Tuesday afternoon and
evening, as a plume of some 400-800 J/kg (even approaching 1000
J/kg across our southernmost tier of counties) develops.  Kinematics
aren`t impressive, however - even the high end of ensemble guidance
keeps deep shear below 20kts, with basically no curvature.  So,
severe threat with any of this activity looks minimal.  Only other
story is temps, which look to land some 10-12 degrees above normal
Monday afternoon, and then 6-9 degrees above normal on Tuesday.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
As of 151 PM  EDT Saturday...

Key Messages:

1) Daily shower and thunderstorm activity is likely each afternoon
from Wednesday through Saturday, but with minimal severe risk.

2) Warm and muggy conditions are expected through the period.

A murky upper pattern will set up for the remainder of the seven-day
forecast.  Relaxed, quasi-zonal flow will persist the remainder of
the week, providing little, if any, synoptic forcing to drive the
deteriorating frontal zone out of our region.  Diurnal showers and
thunder can thus be expected each evening (with similar low risk of
severe weather) across most of the area.  The latest 12z round of
ensemble guidance has backed off significantly on the potential for
a mid/late-week shortwave to cause any reactivation of the
boundary...the remnants of which are now favored to remain in our
area right through the end of Day 7. Temperatures, accordingly, will
remain a couple categories above normal through the period.

&&

.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
At KCLT and elsewhere: VFR and dry with primarily S/SSW winds through
the 00Z TAF period. Lighter winds will linger through daybreak.
Winds will increase slightly on Sunday but will be lighter compared
to the last few days as no gusts are expected. Cirrus will remain
mostly BKN through the period. A VFR cu field should develop under
the cirrus shield Sunday afternoon/early evening.

Outlook: Dry and VFR continues Sunday night into Monday. Periodic
rain chances and restrictions return Monday night and may linger
through the middle of of next week as a frontal boundary stalls
across the region.

&&

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

&&

$$

SYNOPSIS...AR/MPR
NEAR TERM...AR/TDP
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...AR