Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 241830

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
230 PM EDT SUN JUL 24 2016

Broad high pressure will linger over the region through the week
before a mid level disturbance crosses the forecast area on Friday.
Moisture levels will gradually increase across the western Carolinas
and northeast Georgia by the middle of the week while a stationary
front remains across the mid Atlantic region.


As of 230 pm EDT, very warm profiles across the region are making
conditions a bit more inhospitable to convection than in previous
days. The MSAS SBCAPE analysis does show afternoon values of 2000 to
3000 J/kg across the southern piedmont and NE Georgia - with lesser
values farther north. Additionally, DCAPEs are a robust 1000 to 1400
J/kg across the region so isolated severe still has a chance if
better coverage can materialize. However, all the recent HRRR runs
are relegating afternoon and early evening coverage to the southwest
mountains and extreme lower piedmont.

Otherwise, A zonally-oriented 594 dm 500 mb ridge will remain over
the region through Monday. Any lingering late evening convection
will quickly diminish and we will see another night of mild min
temps 4 to 8 degrees above climo along with mountain valley stratus
and fog. Scattered convection will develop in the mountains again on
Monday afternoon - with similar coverage to today. A persistent
surface lee trough will keep winds light S to SW through the period
except a bit more westerly across the mountains. Expect plenty of
mid 90s maxes Monday afternoon, but with heat index values likely
peaking at 101 to 103 again in the lower piedmont. Southern Elbert
County and Eastern Union County NC will be the closest to approach


At 210 PM Sunday: On Monday night and upper ridge will centered off
the coast of the Carolinas, extending west and inland to the
southern Appalachians. Although the ridge remains in place off the
coast through Wednesday, there are some indications that falling
heights to our north may reach as far south as northern NC.

At the surface, weak troughing will be in place Monday night along
the eastern seaboard, while a weak cold front drops south over the
OH River Valley. The front slows to our north on Tuesday, while
moisture ahead of the boundary increases over the southern
Appalachians. By Wednesday there is some discrepancy in the models
on the position of the front, with some indications it will reach NC
or even northern SC, brining even more moisture to the area.

Instability will be sufficient to support convection through the
period, perhaps lingering overnight depending on models sources, but
shear appears to be limited and not supportive of organized
convection. Steering flow appears weakest during daylight hours, at
least at lower levels, perhaps supporting slow moving cells and
locally heavy rainfall. Temperatures will run three to five degrees
above normal. Apparent temperatures do not appear to exceed 100


As of 210 PM Sunday...Good confidence is had in the ext range as the
op models continue in agreement with the ulvl pattern and to some
extent the lower levels. The ECMWF builds the subtrop ridge farther
west than the GFS across the nrn GOM...however moisture flux
differences will not appreciably affect the sensible wx. Broad flat
ridging will dominate the srn CONUS Thu with gradually lowering
heights across the east through the period as a broad H5 trof swings
across the Glakes region. This trof will push a weak cold front
toward the area by Fri and the airmass ahead of the front will
remain seasonably warm and moist. Likely pop coverage will favor the
NC mtns through the period with pulse stg/svr tstms developing each
afternoon. Slight to sct mention will be maintained non/mtns. The
persistent synoptic pattern will maintain max/min temps a few
degrees F above normal each day.


At KCLT and elsewhere, the dominant upper ridge is producing very
warm profiles that are making convection less widespread today. KCLT
and KHKY should see nothing nearby. KGSP and KGMU will have slightly
better late day convective chances, but still unmentionable in the
TAF, while KAVL and KAND will need a VCTS in the higher terrain and
nearer the better dewpoint gradient, respectively. Expect light SW
winds through the period, except for more NW flow most hours at KAVL
west of the surface lee trough. Will feature another round of LIFR
to IFR conditions toward daybreak in the mountain river valleys -
including KAVL.

Outlook: Isolated/scattered afternoon/evening showers and
thunderstorms will continue across the mountains/piedmont through
much of the week - with coverage increasing a bit each day. Morning
fog and low stratus will continue in the mountain valleys around
daybreak each day, and also be possible in locations that receive
heavy rainfall the preceding afternoon/evening.

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%     Low   55%     Med   71%
KHKY       High 100%     High 100%     High  94%     High  94%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High  97%     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:



  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      96 1983     68 1985     71 1934     52 1966
   KCLT     100 1983     73 1938     78 2010     59 1947
                1952                    1883
   KGSP     101 1952     70 1985     79 2010     59 1904


  STATION      HIGH        LOW         HIGH        LOW
  -------  ----------  ----------  ----------  ----------
   KAVL      92 2010     68 2000     70 2012     51 1895
                2005                    2011
                1987                    2010
   KCLT     101 2010     69 2000     79 2010     62 1947
   KGSP     100 1995     72 2000     77 2010     57 1911




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