Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 261048

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
648 AM EDT Sun Jun 26 2022

High pressure remains in place over the Southeast through today.
A cold front approaches from the northwest tonight, tracking across
the region Monday into Monday night before stalling south of the
western Carolinas Tuesday. This front will remain stalled out along
the Coastal Carolinas into much of next week keeping shower and
thunderstorm chances around.


As of 621 AM EDT: Shower activity over northeast TN continues to
increase in coverage at daybreak, with a few embedded thunderstorms
now evident. Precip chances will have to be adjusted upward a
bit to account for this. No indication this will cross the mtns
yet. Temps should remain relatively mild with continued sct-bkn
mid level cloud cover.

Over the next 24 hours, we should finally see the upper anticyclone
to our west lose its grip on the srn Appalachians and western
Carolinas as a nrn stream mid/upper trof digs down from the nrn
Plains and across the Great Lakes/Midwest today and tonight. This
evolution should push a cold front down across the Midwest and OH
Valley region. This might not really affect our area much this
afternoon, which will seem similar to yesterday with relatively
modest buoyancy mainly confined to the mtns/foothills, but with less
inhibition east of the mtns. Thus, precip chances are a bit higher
and more expansive than yesterday, but probably overdone in light
of the very dry sfc conditions across much of the region. Poor
lapse rates and weak buoyancy make severe weather unlikely, but
slow storm movement and deep warm clouds make locally heavy rain
a possibility mainly over the mtns. We will have to watch storms
to the west late in the day to see if anything makes a run toward
the NC mountains. Present indication is that storms would weaken as
they reach the NC border. Temps should warm just above normal. The
approach of the sfc front later tonight will keep precip chances
going near the TN border through the overnight.


As of 230 am EDT Sunday: No major changes from previous forecast
thinking regarding the cold frontal passage on Monday. The front
will track slowly eastward across the western Carolinas and
northeast Georgia Monday into Monday night bringing both a better
chance and coverage of showers and thunderstorms than we have seen
in a while. However, we will need to tame our expectations in
regards to the QPF from this FROPA as both global models and GEFS
ensembles continue to show rainfall amounts generally around half an
inch or less across much of the CWA. Despite PWAT values ranging
from 1-2 inches, dry antecedent soil conditions will make it hard
for the FROPA to have any real sfc moisture to work with, so not
expecting this front to help alleviate our abnormally dry conditions
east of the mtns. Shear on Monday continues to trend around 10 to 15
knots. SBCAPE values have trended upward slightly compared to
previous model runs and are now running around 800 to 1,000 J/kg
Monday afternoon. With mostly cloudy skies still anticipated along
and ahead of the frontal boundary, instability will likely be
limited. The SPC currently has the GSP fcst area in a general
thunderstorm risk for Monday, so the severe threat looks to remain
fairly low, if any, for now. Temperatures Monday will be near to a
few degrees below climo.

The cold front stalls south of the western Carolinas on Tuesday
keeping shower and thunderstorm chances around through the rest of
the short term forecast period. How far the axis of moisture from
the stalled front pushes northwest is the main forecast uncertainty
for Tuesday. For now, have the best chance for PoPs mainly along and
east of I-85. Expect much cooler temps, about 5 degrees below climo,
behind the FROPA on Tuesday.


As of 300 am EDT Sunday: Upper-level ridging builds back in across
the southeastern CONUS starting Wednesday and sticks around through
the long term forecast period. Meanwhile, the Bermuda High will
dominate in the western Atlantic. This overall pattern will allow
for daily diurnal shower and thunderstorm chances mid to late next
week. Have PoPs ranging from slight chance to chance each day.
Expect temps to gradually warm throughout the fcst period, starting
out a few degrees below normal Wednesday, becoming a few degrees
above normal Thursday and beyond.


At KCLT and elsewhere: VFR conditions prevailing at all terminals
through at least late this evening, with mainly mid-level clouds
today, but with a caveat. Convective coverage will be better
this afternoon/evening across the mtns and spilling out over the
foothills, so PROB30s have been included in some places and they
will contain a generic MVFR ceiling/vis restriction. Wind will
generally be from the S to SW. Wind loss of heating around sunset,
convection will diminish and wind should go light/variable. A bit
more low level moisture tonight, so KAVL has a better chance of
developing some MVFR fog after midnight. The arrival of a cold
front will not affect most TAF sites before 12Z Monday, but could
bring some showers to KCLT on Monday morning.

Outlook: A stalling front will bring better coverage of SHRA and
TSRA Monday and Tuesday, before forecast confidence drops off
after midweek.  Low-end fog restrictions will be possible each
morning, especially in locations which have received rain the
previous afternoon.




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