Area Forecast Discussion
Issued by NWS Greer, SC
FXUS62 KGSP 261803
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
203 PM EDT Wed Oct 26 2016
A weak and mostly dry cold front will cross the area Thursday. Warm
high pressure returns Friday before another weak frontal passage
occurs late Sunday. Warm and dry high pressure moves in early next
.NEAR TERM /THROUGH THURSDAY/...
As of 140 PM EDT: Satellite imagery shows a shortwave moving through
MO this afternoon, with convection trailing along an associated cold
front back through the southern plains. Meanwhile, surface high
pressure draped along the eastern seaboard will continue to migrate
offshore tonight as the approaching surface cold front crosses the
lower OH and mid MS river valleys. The upper wave is expected to
gradually dampen as it approaches the Appalachians overnight and
crosses the forecast area on Thursday. Upper level forcing will be
quite muted with the trough passage, and the surface front is
expected to only slowly lay over into the region late in the day.
The forecast area should thus remain dry overnight with just small
southwest NC mountain shower chances creeping in on upslope flow
after daybreak. The slightly deeper moisture along the frontal zone
will then spread across the mountains through the day but with just
scattered PoPs advertised. Forcing and moisture appear much less
east of the mountains Thursday afternoon and modest instability will
be relied upon to get much QPF at all. The instability looks quite
reserved in most areas, with SBCAPE possibly reaching 500 to 700
J/kg in the far SW mountains and also southeast of CLT late day. The
thunder potential is slight at best. Expect a milder night with
overnight mins in the 40s and lower 50s throughout as clouds
increase. Maxes should run about a category above climo with
pre-frontal warm advection Thursday.
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
At 145 AM Wednesday: Upper level heights begin to drop ahead of an
incoming cold front Thu morn. This front will have limited moisture
to work with and it loses upper support from a decaying H5 s/w.
Thus...pops have been adj down for Thu thru the entire fropa. Right
now...have chance pops confined to the NC mtns with slight chc
elsewhere thru 18z. Precip chances become more limited in the
afternoon with localized low-end qpf amounts. Mid and high level
cloud cover will help hold max temps right arnd or a bit above
normal. On Fri...upper heights rebound as a small scale Canadian
high pressure area merges with an Atl high thru Fri night. Max temps
will rebound in an increasingly deep subs zone and w/ly llvl flow
to about 10 degrees above climo. Min temps Thu and Fri nights will
be maintained a cat or so above normal levels.
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
At 155 AM Tuesday: Not much change was made to the going fcst. A
high confidence pattern will envelope the srn CONUS as a strong
sub-trop high dominates thru most of the period. A weakness moves
thru the mid Atl region late Sun and swings a dry cold front over
the CWFA Sun night into Mon...but no sigfnt airmass mix will occur.
Max temps will remain a good 10 degrees above normal Sat/Sun...and
with a relative lowering of thicknesses Mon/Tue...max temps will
lower by only a cat or so. Mins will remain above normal by a few
degrees as well.
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
At KCLT: Surface winds will gradually veer as high pressure migrates
off the eastern seaboard and a cold front approaches from the west.
High level cloudiness will gradually increase and thicken and some
model RH profiles hint at MVFR level clouds forming around daybreak.
This moisture return appears overdone and is not carried in the MOS
so will keep cigs VFR for now. No precipitation will be mentioned,
with just slight chances in the forecast after the 18Z cutoff.
Elsewhere: High level cloudiness will increase and lower through the
period, with lower VFR cumulus developing over the mountains and
foothills in warm advection Thursday morning. Expect light surface
winds to slowly turn more S then SW and increase slightly through
the period. Will only mention VCSH near the end of the TAF at KAVL
for now, with moisture and forcing expected to be too limited for a
mention across the foothills. Light fog in the SW NC mountain
valleys will be possible again, but not as dense given the
Outlook: A weak cold front will cross the area Thursday afternoon
and Thursday night, but with very limited moisture. Dry high
pressure will return Friday through the weekend and last into early
18-24Z 00-06Z 06-12Z 12-18Z
KCLT High 100% High 100% High 100% Med 62%
KGSP High 100% High 100% High 100% Med 63%
KAVL High 100% High 100% High 100% Med 63%
KHKY High 100% High 100% High 100% Med 63%
KGMU High 100% High 100% High 100% Med 63%
KAND High 100% High 100% High 100% Low 59%
The percentage reflects the number of guidance members agreeing
with the scheduled TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link: