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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KGSP 281804
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
104 PM EST Sun Feb 28 2021

.SYNOPSIS...
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A cold front will cross Tennessee tonight then cross our
area by mid day Monday.  Dry high pressure will build over from the
north as the high center moves from the Great Lakes to the Mid-
Atlantic coast Monday night into Tuesday. Unsettled weather returns
from the west Tuesday night into Wednesday morning. Another low
pressure system may affect the Gulf Coast region Friday into
Saturday.
-- End Changed Discussion --

&&

.NEAR TERM /THROUGH TONIGHT/...
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As of 1250 pm: Low clouds and fog finally are giving way to incr
gusty SW winds this afternoon. Although hourly temps are running way
behind forecast maxes, we`re hesitant to make any radical changes to
this afternoon`s highs, as temps have been warming by as much as 10
degrees in an hour where surface winds and insolation have
increased. Thus, only made minor tweaks for now.

Weakly forced warm sector regime will yield only spotty-at-best
shower coverage through the evening, with the best chances occurring
in response to mech lift across the srn NC mtns/Blue Ridge
escarpment. The latest short term guidance continues to depict some
modest instability... generally 500-1000 J/kg of sbCAPE developing
in the 75-80 degree air over southern Piedmont areas this afternoon,
with some  convection- allowing models continuing to respond with
some spotty showers... mainly across the eastern SC Piedmont this
afternoon, where slight chance pops are advertised.

The front will take it/s time reaching the NC mtns, likely aft 08z,
when stronger sfc forcing and a llvl jet begin to generate higher
precip rates over the wrn NC mtns. Not anticipating any hydro
threats thru the near term period, but the lingering rainfall into
the short range may create isol and minor flooding over the far srn
NC mtns, mainly in wrn Graham Co thru late morning Mon. Min temps
tonight will also remain well abv normal with readings likely
ranging from the l50s over the mtn valleys to the u50s south of the
I-85 corridor.
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&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
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As of 1205 pm EST Sunday: As sfc ridging rolls over into the region
Monday night, the llvls will continue to dry, but model cross
sections depict varying degrees of mid and upper level moisture
lingering within the west to wsw flow aloft.  Gridded model sky
cover solutions are all over the place, and at this point, the
generic partly cloudy should cover it.  Downstream of developing
southern stream low pressure, clouds should thicken again as Tuesday
wears on and within the cool NE llvl flow, maximum temperatures will
be back to below climo values.

From late day Tuesday into Wednesday morning, as forcing and better
moisture associated with the encroaching southern stream system
overspreads the region, pcpn will be become widespread.
Vertical temperature/moisture fcst profiles over the NC mtns
still suggest that a period of snow developing into a wintry mix
remains possible during this time.

Fast moving s/wv passage is expected on Wednesday, the axis of which
is timed to be near the coast by the afternoon.  Whatever the
orientation and cvrg of pcpn shield is in the morning should be
replaced by dry slotting by Wed afternoon.
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&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
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As of 1215 pm EST Sunday: No change to the going dry and mild fcst
for Thursday as extended range guidance remains in good agreement in
progging deep layered dry air within the cyclonic flow aloft and a
dry northerly llvl flow.  Within the lingering llvl northerly flow,
a dry cold front is progged drop south through the region on Friday
ushering in another period of below climo temperatures.

The mean pattern does not change very much for next weekend,
featuring a lingering eastern CONUS trough.  Forcing rounding the
base of upper trough is progged to activate baroclinic zone, but way
off to our south and into the offshore Atlantic on Saturday into
Sunday.  The dry conditions will continue with temperatures around 5
deg F below the early March climo each day.
-- End Changed Discussion --

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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At KCLT and elsewhere: Lingering low cloud cover is scattering/
clearing early this afternoon and visby is (finally) improving
quickly in the KCLT area. VFR conditions should be seen at all sites
no later than 20Z. Most terminals will see gusty S/SW winds this
afternoon that will likely diminish a bit this evening. However, SW
winds should begin to pick up again after midnight as surface
gradient increases in advance of an approaching cold front. Can`t
rule out a brief return of fog btw roughly 03-06Z. However, fog
chances will decrease once winds pick up late tonight. Cigs should
lower to MVFR after midnight as rain chances also increase. Most
sites will see categorical SHRA for several hours from around
daybreak through the morning. Improving conditions are expected at
KCLT during the 18Z-00Z Monday outlook period, with NW winds
developing in the wake of the front.

Outlook: Drier high pressure building back into the area late Monday
will result in improving flt conditions through early Tuesday.
Moisture will then surge back into the area by the end of the day
Tuesday, with restrictions and precipitation chances returning Tue
night into early Wed. Another round of drying is expected by late
Wed, likely continuing through the end of the work week.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High  89%     High 100%     High  91%     High  97%
KGSP       High  90%     High  99%     High  95%     High  96%
KAVL       High  99%     High  95%     High  86%     High  94%
KHKY       High  89%     High  95%     Med   74%     High  88%
KGMU       High  91%     High  97%     High  95%     High  95%
KAND       High  91%     High 100%     High  95%     High  95%

The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables are available at
the following link:

www.weather.gov/gsp/aviation
-- End Changed Discussion --

&&

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

&&

$$
SYNOPSIS...DEO
NEAR TERM...JDL/SBK
SHORT TERM...CSH
LONG TERM...CSH
AVIATION...JDL