Area Forecast Discussion
Issued by NWS Greer, SC
FXUS62 KGSP 231046
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
646 AM EDT TUE AUG 23 2016
High pressure will persist over the region through midweek allowing
temperatures to climb back above normal. Another weak cold front will
approach the Western Carolinas from the northwest toward the end of
the work week, with high pressure building back to our north in the
.NEAR TERM /THROUGH TONIGHT/...
As of 645 AM EDT...Only minor tweaks to the sky and wind grids with
the latest guidance for the 12z TAFs. Otherwise, the forecast is on
As of 300 AM EDT...A large area of upper-level high pressure will
persist across the Deep South today, keeping the area weather quiet.
At the surface, high pressure will drift east from the central
Appalachians to the Mid-Atlantic coast by late tonight. Low-level
easterly flow will remain weak, but may provide enough upslope
forcing to keep a fair amount of high-based stratocumulus around for
much of the day and again tonight. Still expect partly to mostly
sunny skies for most of the area today with temps at or a category
below normal. The NAM seems to be struggling with the low-level
moisture and breaks down the mid level subsidence inversion down,
resulting in healthy SBCAPE across the SW NC mountains the Upper
Savannah Valley this afternoon. The CAMs also develop some shallow
convection across the area. Overall, I think only a slight chance
PoP across the NE GA counties looks warranted where dewpoints will
be the highest. Lows tonight will be near normal under party cloudy
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 310 AM EDT Tuesday...the short term fcst picks up at 12Z on
Wednesday with mid to upper level ridging building over the SE
region and persisting well into the medium range. At the sfc,
high pressure will be slowly moving off the eastern seaboard on
Wednesday and Thursday keeping a surface wedge over the CWFA. A
fairly broad area of deeper, pre-frontal moisture will pass to
our north during the period. Some of the deeper moisture could
spread over extreme Western NC, however the prevailing wedge pattern
should prevent it from spreading farther east. As for the sensible
wx, most of the convective activity should be limited to the higher
terrain zones during the afternoon and early evening hours. Temps
will start out around climatology and warm thru the period with
highs on Friday about a category above normal.
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 305 AM EDT Tuesday...the medium range fcst picks up at 12Z
on Friday with broad upper ridging in place over the SE region.
The ridge is expected to remain largely in place thru day 7 with
some flattening likely by the end of the period. At the sfc, a
weak and mostly dry cold front will be moving thru the CWFA early
Friday with another round of high pressure in its wake. The center
of the high will move over the Great Lakes late Fri/early Sat
bringing bndy layer winds around to north and then northeast. The
high eventually lifts north of New England early next week while
another low develops over the Northern Plains. There are some notable
differences between the long range models with the 12Z ECMWF still
developing a tropical low over the Bahamas and moving it over
Southern Florida early next week while the GFS does not develop
a low. As for the sensible fcst, no major changes were needed with
below climo POPs for the period and temps about a category above
normal for late August.
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
At KCLT and elsewhere: VFR conditions expected through the period,
except for possible mountain valley fog and stratus again tonight.
As high pressure slides east across the Mid-Atlantic today, light
easterly upslope low-level flow will continue, supporting patches of
stratocumulus for most of the period, with occasional CIGS possible
in the 4000-6000 ft range. Winds will be light thru the period,
favoring a NE direction through the morning, then veering to more
ESE during the afternoon. Some of the guidance turns the winds back
to NE at KCLT and the Upstate sites early evening. But most keep it
ESE at KCLT overnight.
Outlook: The dry air will remain in place across the area resulting
in fair weather through at least mid-week.
10-16Z 16-22Z 22-04Z 04-06Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL Low 57% High 100% High 100% High 100%
KHKY High 100% High 100% High 100% High 100%
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: