« Back
NWS Peachtree City, Ga » Text Product » GSP Area Forecast Discussion

Printer-friendly Version
Current Version              Previous Versions:   1  2  3  4  5  6  7  8  9  

Area Forecast Discussion

FXUS62 KGSP 010728

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
328 AM EDT FRI JUL 1 2016

An upper trough will push a cold front through the region today and
tomorrow.  The front will stall just to the south of the area by
Saturday, but then will lift slowly back north late in the weekend
into the beginning of next week.


At 0330 UTC: An upper trough extended from Hudson Bay to the Gulf of
Mexico. This featuer is expected to deamplify and progress the the
east coast tonight. The bulk of shortwave energy moving through the
trough will pass well to our north, but the models suggest some weak
energy crossing the mountains today and tonight.

At the surface, a surface front now over the Carolinas and Georgia
will weakend and shift slowly east today, while a better defeind
cold front reached the mountains from the northwest. Although
mositure with the new front is more limited than with the previous
front, model souding forecasts show enough instability and moisture
to suport convection this afternoon and evening, mainly east of the


As of 245am EDT Friday:  Generally zonal upper flow pattern Saturday
morning gradually transitions to southwesterly flow as next
continental trough approaches the area.  Some shortwaves embedded in
this flow will give some chance for afternoon thunderstorms Saturday
and Sunday, especially over higher terrain.  Sunday will have a
better chance for thunder due to a stronger shortwave passage and
some increase in BL moisture as surface flow becomes more
southwesterly ahead of progressive trough over the central CONUS.
Temperatures will continue at 3 to 5 degrees above normal, and winds
should be light with fairly weak surface features.


as of 315am EDT Friday: Weak upper trough is expected just east of
the Southern Plains Monday morning with weak zonal to southwesterly
flow aloft over the CWA.  Upper trough is weaker in the EC model
than the GFS, practically washing-out by Tuesday.  Nonetheless,
passage of this feature will enhance the chances for precip. Monday
and Tuesday with diurnally favored scattered afternoon convection
the main result.

a fairly low-amplitude flow pattern aloft persists through Friday
with a resulting tropical airmass that will give temperatures 3 to 5
degrees above normal, mostly light winds with some afternoon gusts,
and a chance for afternoon thunderstorms every day through Friday.


At KCLT: Convection remains possible before dawn, mainly to the
north. Guidance suggests low a VFR CIG before dawn. A guidance blend
supported vsby restrictions to the north, but not at the field. A
decrease in cloud cover after dawn will be less supportive of
restrictions, and primary cloud heights are expected to be higher as
well. Winds will favor the SW, with minor gusts during the day.
Convective chances increase again in the afternoon as heating and
instability increase.

Elsewhere: Convective chances remain at NC sites before dawn. MVFR
vsby is expected at NC sites and KAND by dawn. Guidance is
supportive of early morning MVFR ceiling restrictions at all sites
by dawn. A decrease in cloud cover and a rise in prevailing cloud
heights is less supportive of ceiling restrictions after dawn. Winds
will favor the SW in the foothills and NW at KAVL overnight and
during the day on Friday, with modest gusts. Winds will veer NW at
KHKY Friday evening as a cold front arrives. Convective chances ramp
up again this afternoon with instability ahead of the front, mainly
east of the mountains.

Outlook: Diurnal convection expected to return to typical summertime
coverage Saturday.  Another series of fronts, and potential weak
low pressure systems riding along the fronts, appears on tap
for Sunday through Tuesday.  This period may offer an enhanced
thunderstorms possibilities.

Confidence Table...

            07-13Z        13-19Z        19-01Z        01-06Z
KCLT       Med   72%     High  91%     High 100%     High 100%
KGSP       Low   58%     High  88%     High 100%     High 100%
KAVL       Med   60%     Low   52%     Low   55%     Low   57%
KHKY       Med   62%     High  85%     High 100%     High 100%
KGMU       Med   66%     High  87%     High 100%     High 100%
KAND       Med   70%     High  89%     High 100%     High 100%

The percentage reflects the number of guidance members agreeing
with the schedule TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.