Area Forecast Discussion
Issued by NWS Greer, SC

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS62 KGSP 231337
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
937 AM EDT Sat Mar 23 2024

.SYNOPSIS...
A low pressure system will maintain cool temperatures and periodic
light rain today. High pressure builds in from the north Sunday into
Monday bringing drier weather, before a moist cold front arrives
from the west late Tuesday.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 626 AM EDT Saturday: For the morning update, visible satellite
shows the upper cloud deck starting to break up across the Piedmont,
allowing for lower clouds to lift. Radar shows just a few lingering
showers across the TN/NC border. Adjusted PoPs to account for the
few showers still in the CWA, but should continue to diminish as the
FROPA approaches from the west. Minor adjustments to winds to better
time the arrival of the front later today.

Otherwise...The supporting upper low will de-amplify come morning
and phase with a passing northern-stream shortwave, such that by
afternoon the Carolinas will be ensconced in deep-layer N flow.
Gusty winds are expected everywhere this afternoon...still falling
just shy of advisory criteria.  Granted, ensemble probs support
a 75% chance of advisory-level gusts over the high terrain of
Yancey, Mitchell, and Avery Counties this evening, but over such
an isolated area encompassing only the highest elevations that an
advisory isn`t reasonable.  Highs this afternoon will land around
normal for most locations despite strong CAA. Winds will stay
elevated through tonight, as skies clear.Although the atmosphere
will struggle to decouple under these conditions, temperatures will
manage to fall to near freezing across most zones (or below freezing
at the higher elevations).For most locations, it`ll be too breezy
all night for any frost concerns...although some spots in the
Savannah River Valley could see patchy frost before daybreak.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
As of 150 AM Saturday...A drying period is in store over the short
range as an upper ridge axis crosses east. Meanwhile, stg hipres
will track across ern Canada and ridge down the east coast. This
will bring a cP airmass mix each day, moreso on Sun, and modest CAA
will keep high temps a little below normal. Soundings show a very
dry subs inversion persisting just abv the mixed layer and if
parcels are able to tap into this air, there will be enuf momentum
transfer to bring lower td/s to the sfc. Have adjusted sfc td/s down
both days using a RAP mixing tool Sun and the NBM 10 percentile mix
for Mon. This has yielded lower RH values with percentages likely
dropping below 25% across most areas Sun. Vertical dry air mixing
may be offset a little more on Mon, due to e/ly BL flow, but there
is still a good chance of RH levels nearing 25%. With winds
remaining elevated and gusts likely across the NC mtns, Sun/Mon
could see fire-wx concerns enhanced beginning before noon lasting
through the afternoon. Max temps will remain abt a cat below normal
with the cP mix and slow modification. Mins Sun night will come
close to freezing across NC Piedmont where the growing season has
begun, so a freeze product may be needed for a part of that area.
The llvl CAA reduces Mon and e/ly flow will likely hold mins abv a
frost/freeze concern.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 250 AM Saturday...The ext range still looks unsettled as a
progressive springtime pattern ensues across the CONUS. Very broad
troffing will setup to the west to begin the period with the better
mlvl energy remaining north of the FA. A srn portion of the trof
will be the main weather driver Tue through Thu as an active frontal
zone gets pushed into the area. Upper divergence remains weak with
the h3 jet core aligning west and into the OH Valley while the sfc
features are not great for convec development as the BL flow remains
e/ly and rather stable. There could be some convec enhancement
across the sw/rn zones Tue as the sfc front interacts with an insitu
wedge and llvl convrge increases, but the thermal profiles still
look meager for much available buoyancy. This looks more like a rain
maker and perhaps some high elevation -snsh before the front crosses
east Wed. However, the GFS is now quick to develop cyclogenesis
across srn GA and moves a low up the front Thu bringing additional
rounds of wrap around precip on Thu. The other models are showing
something similar but are displaced farther south and later to
develop. So, much uncertainty remains with this system and the
details will continue to be figured out as we near the event. Temps
will be tricky depending on the evolution of the mass fields, but
will generally expect below normal highs Tue with a slow warming
trend thru the period. Mins will likely remain elevated abv normal
in a generally moistening environment.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: We`ve settled into a jumble of ceilings
ranging from MVFR to LIFR this morning as rainfall lifts out of the
area altogether.  No further degradations are expected.  In fact,
slow improvement is expected after daybreak, as rainfall lifts
north and things begin to dry out.  CIGs will be slow to scatter
out...but it`s only mildly optimistic to expect VFR conditions to
return by mid-afternoon.  Increasingly potent N/NW wind gusts will
develop by late morning at all the terminals, especially KAVL,
as the system pulls east.  Clear, VFR conditions and a hefty N
wind will remain in place Saturday night...with winds tapering
off into Sunday.

Outlook: Dry high pressure and VFR conditions will continue the
rest of Sunday into Monday. Rain chances and possible restrictions
will return Tuesday into Wednesday as a cold front moves in from
the west.

&&

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

&&

$$

SYNOPSIS...SBK
NEAR TERM...CP/MPR
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...MPR


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.