Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 170238

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1038 PM EDT Sat Sep 16 2017

Weak high pressure will persist across the region into Monday.
Hurricane Jose is forecast to remain over the Atlantic and appears
unlikely to impact the Carolinas or Georgia.  A more summer like
pattern will highlight the weather next week with diurnal rain
chances and above normal temperatures expected.


The upper pattern slowly evolves over the next 24 hours with a
positively tilted upper trof axis remaining to our west, thus the
relatively dry NW flow aloft will continue through Sunday. In this
case, persistence is a good forecast. Weak high pressure ridging
down from the north should allow for another round of patchy dense
fog in the mountain valleys late tonight and first thing Sunday
morning, although today`s trends in surface dewpoints suggest the
fog may form later and not be quite as widespread as in previous
mornings. After the fog burns off, expect more ridgetop cu and a
small chance of showers across the highest terrain. Temps will be a
tad above normal.


As of 215 PM EDT Saturday: T.C. Jose will continue to track north
offshore of the Mid-Atlantic coast Mon-Tue, while an upper ridge
tries to hold on across the eastern CONUS. Some shortwave energy
will lift out of a deep longwave trough over the Rockies and weaken
the eastern ridge as it lifts into the Great Lakes. But this will
have little effect on our sensible weather down this way. Northerly
flow around the west side of Jose will reinforce dry and seasonably
warm temps. There may be enough moisture for a few showers in the
high terrain, but anything that develops should be shallow and
isolated in nature. Temps will be about a category above normal for
AFTN highs and a couple categories above normal for overnight lows
both days.


As of 100 PM EDT Saturday: Continued above normal temperatures are
slated for Wednesday with the cwfa oriented within the eastern
periphery of the llvl return flow moisture.  In concert with
encroaching s/wv energy, diurnally fired deep convection remains
possible for the mtns.  The sensible weather atop the region may not
change a whole lot for Thursday with what is shaping up to be a
pretty weak flow regime lingering acrs the SE conus.  Ridge axis
center remains progged to strengthen atop the NE conus throughout
the latter half of the period.  The accompanying increase in
easterly flow/atlantic moisture influx atop the Carolinas will allow
temperatures to return to near climo by Saturday. The extended range
guidance is giving mixed signals with respect to any increase in
shower activity Friday and Saturday, but the consensus keeps
probabilities in the low chance range through the end of the


At KCLT and Elsewhere: Main concern this period will be timing the
formation of fog/low stratus in the mtn valleys. The near-surface
layer is a bit drier than in prior days, so it stands to reason that
the timing of restrictions should be delayed from what was observed
Fri night/Sat morning. Therefore, a tempo for LIFR conditions is
advertised at KAVL btw 07-09Z, with categorical LIFR from that point
through 13Z or so. The non-mountain terminals should be generally
free of restrictions, but would not rule out a brief period of MVFR
visby toward sunrise. Also, KHKY has seen a brief period SCT/BKN
clouds at 001 the past couple of mornings, so a tempo for SCT002 was
included from 10-12Z. Otherwise, light N or light/vrbl winds tonight
should become NE in most areas by late Sunday morning.

Outlook: Isolated, mainly high terrain diurnal showers will remain
possible through early next week. Morning mountain valley
fog/stratus are also expected each day.

Confidence Table...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High  95%     Low   50%     High 100%     High 100%
KHKY       High  95%     High  83%     High 100%     High 100%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High  95%     High 100%     High 100%

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:




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