Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 301802

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
202 PM EDT Fri Sep 30 2016

Dry southwest flow will linger across the region through this
weekend. Progressively warmer temperatures are on tap through early
next week. The path of tropical cyclone Matthew will be closely
watched as it tracks north near the Atlantic coast next week.


As of 155 pm EDT, a deep closed low pressure system over the OH
Valley late today will keep a strong upper jetlet over the
Appalachians tonight before it lifts northeast through Saturday. Any
associated upper divergence will remain north and east of the area.
Meanwhile, abundant dry air will continue to wrap into our region on
the SE side of the closed low. This will lead to good radiating
conditions tonight and yield min temps below climatology. Dry
weather will persist on Saturday as a weak surface trough lingers
along the Blue Ridge. Thicknesses will rebound slightly and full sun
will raise maxes about a category above climo Saturday afternoon.


At 200 PM Friday: On Saturday evening an anomalous closed upper low
will be centered north of the OH River Valley, with associated low
pressure extending outward to the Great Lakes, much of the East
Coast,a and the Gulf Coast. This low drifts toward New England early
next week. Meanwhile, low amplitude high pressure crosses the MS
River Valley, with nearly zonal upper level flow extending across
the Southeast.

At the surface, on Saturday evening a deep surface low will be
centered near the border of MI, IN and OH, while a weakening cold
front reaming off the east coast. Dry air between these two features
will extend from the Gulf Coast to at least VA. Modest moisture
spreads over our area from the west by Monday as the surface low
moves toward New England. The models show instability increasing
over the Southern Appalachians by Monday, but perhaps not enough to
supporting convection if a warn nose aloft can persist. Temperatures
will warm from near normal to slightly above normal as heights rise
aloft in the wake of the departing surface low.


As of 145 PM Friday: No changes needed to the inherited dry and warm
fcst to start off the period underneath the weak flow regime aloft.
Max temperatures Tuesday are slated to be just a few deg F less warm
than persistence within the tightening easterly flow between TC
Matthew and moderately strong sfc hipres center over New England.
The effectively dry fcst should continue through Wednesday, although
it should be a little less warm given the tightening northeasterly
sfc pressure gradient. During the latter half of the workweek, TC
Matthew remains progged to trek northward within the offshore
Atlantic waters. Mainly dry persistance fcst on tap for Thursday
within the continued NE llvl flow. On Friday, mid-conus upper trough
should be able to make some eastward progress with attendant but
weakening cold front possibly ringing out some showers across the NC
mtns, but we`ll see. At any rate, it could easily remain dry for
another day, and max temperatures will remain above normal.


At KCLT and elsewhere, drier air continues to wrap into the region
from the southwest and VFR conditions will likely persist throughout
the TAF period. The only location of concern is KAVL in the French
Broad River Valley where LAMP guidance produces low restrictions in
fog overnight. However, this does not appear to be supported by the
low crossover temperatures indicated by mid 40s dewpoints occurring
this afternoon. Expect mainly light S to SW winds east of the
mountains and more variable flow in the mountain valleys.

Outlook: VFR conditions are expected in most places through the
early next week as dry high pressure settles in over the area.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High 100%     High  97%     High  94%
KHKY       High 100%     High 100%     High  83%     High  97%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     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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