716
FXUS62 KGSP 170527
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
127 AM EDT Thu Apr 17 2025

.SYNOPSIS...
Dry high pressure lingers over the area through the weekend and
temperatures warm a little each day.  A cold front will approach
from the west early next week, and could bring some showers and
a thunderstorm or two to the area on Monday and Tuesday.

&&

.NEAR TERM /THROUGH TODAY/...
As of 940 PM...

Key Messages:

1) Clear conditions tonight may result in patchy frost in a few
mountain valleys and in a few spots along/north of I-40 in NC.

2) Mostly sunny Thursday and still dry. Less potential for fire
danger.

High pressure now centered over the central Great Lakes will build
SE`wd this evening and center over the CWA by morning. Winds have
generally become much lighter since late afternoon with decoupling
evident in some spots, although portions of the I-85 corridor
maintain a light SW wind and higher dewpoints where the high has
not yet had an impact. Not expecting the high to build in like a
cold front and induce a sharp decline in either of those elements,
although calming/drying should arrive by midnight or a little
later. Already seeing temps fall off more rapidly, however, in those
spots that have already decoupled. Overall, though, the min temps
forecast by the day shift appear on track, a few degrees below NBM
in the outlying areas. Lows will still fall into the mid to lower
40s across the low terrain, and winds will gradually veer around to
the northeast before daybreak. Upper 30s are possible in isolated
or typically colder spots in the Piedmont/Foothills north of I-40,
with mid to upper 30s in mountain valleys. Despite relatively
low dewpoints, the decoupled PBL eventually exhibits dewpoint
depressions small enough that where temps fall into the mid 30s,
some frost now appears possible. Think it is too patchy to warrant
an Advisory, but a mention has been added to the forecast grids.

Another sunny day is expected tomorrow, with winds out of
the southeast and temps around a category warmer than today`s.
A steady increase in low-level moisture owing to strengthening SE
flow off the Atlantic will result in dewpoints not quite as low
as today`s, so fire weather should be somewhat less of an issue.
Cloud cover will begin to increase late in the period with a weak
vort blob seen on model progs and moisture AOA about 700 mb. With
low levels remaining dry and only weak forcing, this is not enough
to warrant a mentionable PoP except for a couple of spots in the
northern mountains. Some virga could be seen elsewhere.

&&

.SHORT TERM /TONIGHT THROUGH SATURDAY/...
As of 2:15 PM EDT Wednesday: Broad southerly return flow will become
established over the area as high pressure moves off the
Southeast/Mid-Atlantic coast late in the week. After the 850 mb
ridge axis passes through, a warm front will quickly lift northward
through the area Thursday night. Weak isentropic lift across the
boundary and additional forcing from a mid-level shortwave trough
could be accompanied by an increase in cloud cover at night, but the
system is generally moisture starved, so the forecast remains dry
with PoPs below 20 percent.

The warm front will move well to our north on Friday, resulting in a
significant warming trend with temperatures about 10 degrees above
normal (highs in the 70s in the mountains, lower 80s elsewhere)
Friday and 10-15 degrees above normal Saturday.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
As of 2:15 PM EDT Wednesday: Surface high pressure will remain
anchored to our north over the Northeast US and to our east the
Southeast U.S. coast through early next week. Meanwhile, a southern-
stream shortwave trough and attendent surface low is expected to
lift northeastward from the Great Plains to the Great Lakes. A
trailing cold front will approach from the MS Valley. Tend to favor
a slower solution with arrival of the front as amplified S-SW flow
across the eastern seaboard becomes oriented more parallel to the
boundary, causing its eastward progression to slow. The most likely
timing of the front is Monday afternoon or night, but it could be as
early as Monday morning. If the downstream ridge block does not
break down as quickly as the model consensus currently depicts it,
there is a potential for this front to stall just to our east near
the coast. This would prolong the chances for rain showers into
Tuesday. The NBM shows an increasingly large spread in temperatures
Monday night and Tuesday owing to the uncertainty in the pattern.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
At KCLT and elsewhere: VFR through the period. NNW winds to start
the period will diminish, briefly lgt/vrb before veering around E to
SE by later this morning (current timing is 16z at KCLT). Direction
will continue on around the dial toward S (except for KAVL remaining
SE down-valley), though more lgt/vrb again with high pressure in
control overnight. Wind speeds at best 5-10kt this afternoon with
mixing. High to mid-level cloudiness will increase this afternoon
and evening especially across NC sites but no restrictions expected.

Outlook: Dry/VFR conditions will continue into the weekend.
The next chance of rain and associated restrictions won`t be until
early next week.

&&

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

&&

$$

SYNOPSIS...DEO/MPR
NEAR TERM...MPR/Wimberley
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...TDP