Area Forecast Discussion Issued by NWS Greer, SC
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KGSP 251858
AFDGSP
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
258 PM EDT Mon Mar 25 2024
.SYNOPSIS...
Dry and cool high pressure will persist through tonight as
high pressure over eastern Canada ridges down our East Coast. Rain
returns on Tuesday ahead of a cold front approaching from the west.
Low pressure forms along the front over Georgia Wednesday night then
moves northeast taking the front and ending the rain on Thursday.
Clear weather will return by Thursday night, with dry and warmer
conditions going into the weekend.
&&
.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
As of 2:35 PM EDT Monday: High clouds have thinned across much
of the SC Upstate over the past few hrs, while remaining more
opaque across most of western NC. This pattern will likely con-
tinue into the evening until lower clouds begin to spread over
the area from the south as profiles begin to moisten more sub-
stantially.
Otherwise, stout upper ridging will linger over our region well
into Tuesday as very broad/deep upper trofing gradually spreads
further eastward. The upper trof will eventually push the ridge
axis off the Atlantic Coast by the end of the near-term period
late Tuesday. At the sfc, broad high pressure will linger over
much of the Eastern CONUS today and tonight. On Tuesday, stout
low pressure will lift NE over the western Great Lakes and move
an occluded front over the Southeast. The front will eventually
erode/dissipate whatever is left of the sfc high across our area
by late Tuesday. It will also bring sct to widespread showers to
our area Tuesday afternoon and evening. We`re still not expecting
much in the way of thunder thru tomorrow evening, but most of the
near-term guidance does have minimal amounts of elevated CAPE across
our southern and western zones, so they could see a few lightning
strikes tomorrow aftn/evening. In addition, QPF amounts are still
not expected to be excessive across our area, but our NE Georgia
and upslope zones could see 1 to 2 inches thru 00z Wednesday.-- End Changed Discussion --
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
As of 210 PM Monday: Picking up the short term in the middle of an
ongoing system moving through the area. Aloft, a strong upper low
strengthens over the upper Midwest and deep troughing carves out a
path across much of the CONUS. Over the CWA, a cold front is
anticipated to cross the mountains and linger in the eastern zones
of the CWA. At this time, most of the forcing from the lingering
shortwave will be too far north for any severe weather concerns.
Tuesday night and into Wednesday morning, moisture filtering in from
SW flow will start to be pinched off as strong high pressure from
Canada seeps into the CWA. Guidance from the GFS and EURO keep
precip chances and moisture concentrated to the far eastern portion
of the area through Wednesday night, before the shortwave is ejected
eastward by a lifting trough. By Thursday, flow turns NW as drier
air moves into the area and the cold front completes its march
across the region. Again, looking at any sort of severe ingredients,
a minimal window for some sbCAPE before in the late afternoon on
Wednesday evening. As mentioned before, the forcing will not be
there to support severe weather development and confidence is very
low for it. QPF response for this system continues to be scaled
back, especially over the western zones as the drier air pushes in
quicker with each guidance run. Rain amounts will be a sharp
gradient with the least in the west and most at the eastern fringe.
Other than rain, winds will start to pick up on Thursday as a strong
area of baroclinity spreads through the area as the trough lifts NE.
Temperatures will be mild with a tick cooler values on Thursday due
to a brief stint of NE surface flow. Overnight should remain well
warm with the lingering moisture.-- End Changed Discussion --
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
As of 215 PM Monday: Once the rain lifts out of the area, high
pressure will continue to dominate through the extended period.
Aloft, flow becomes more quasi zonal as a weak ridging pattern sets
up over the majority of the central CONUS. Meanwhile, strong high
pressure starts to amplify over the Gulf and continues to strengthen
through the period. Guidance from the GFS show a steady increase in
PWATs over the weekend and into the beginning of next week as the
high to the south churns in additional moisture. As heights
gradually rise over the weekend, temperatures increase as well to
more spring-like values. The area could see 80s to start next week
with a warm weekend on tap. As for any chances of precip, GFS and
EURO are not in agreement with a potential shortwave passing the
northern portion of the CWA Saturday night into Sunday, with minimal
QPF response. If this occurs, there could be a brief stint of
showers, but nothing substantial or remarkable. As for any fire wx
concerns, RH values could dip into the upper 20 percent range Friday
and Saturday before moisture returns to the region. Winds on Friday
could be elevated, especially across the mountains, but it`s too
early to pinpoint anything too specific.-- End Changed Discussion --
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
At KCLT and elsewhere: Expect VFR conditions to continue thru
tonight at all terminals. Cigs will begin to lower over the
higher terrain first, with KAVL expected to go MVFR just after
midnight. The Upstate sites will then go MVFR by roughly 10z.
Expect cigs at KCLT to remain low-end VFR thru 00z Wed, but
they certainly could drop below 3000 ft the closer we get to
that time. As for rain chances, I expect any widespread precip
to hold off until just after the end of the taf period for all
terminals. KAVL will have the best chance of seeing prevailing
rain before the taf period ends at 18z, but even there, I just
have a PROB30 for -RA beginning at 14z tomorrow. I included
PROB30s for -RA at the other taf sites as well for the last
few hrs of the period. Outside of the mtns, winds will continue
to favor an ELY direction with some sporadic low-end gusts thru
the period, with KCLT veering to a more SELY direction later
tomorrow. At KAVL, winds will remain S to SE thru the period
with low-end gusts likely thru most of the taf period.
Outlook: Sct to widespread showers and associated restrictions
return late Tuesday into Wednesday as a cold front moves in.
Lingering showers could keep restrictions in place well into
Thursday.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...Increased Fire Danger until 8 PM EDT this evening for GAZ010-
017.
NC...None.
SC...None.
&&
$$
SYNOPSIS...DEO
NEAR TERM...JPT
SHORT TERM...CP
LONG TERM...CP
AVIATION...JPT