Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Greenville-Spartanburg SC
321 am EDT Friday Jul 31 2015
dry high pressure will build in behind a departing cold front today
and remain in place through the weekend. Low level moisture will
gradually return through next week as another cold front approaches
from the north.
Near term /through tonight/...
at 300 am EDT Friday...an upper ridge will slowly retrogress today and
tonight from the Southern Plains to the southern rockies...while an
upper trough amplifies over the eastern USA. A cold front will move
slowly south and out of our area...stalling near the coast of the
Carolinas and Georgia. Moisture associated with this boundary appears to
generally remain just southeast of our area...offering little support for
convection. Temperatures will run near normal today and tonight as
weak cool advection is offset by limited downslope warming flow in
light northerly winds.
Short term /Saturday through Sunday night/...
as of 150 am Friday...quiet weather expected through the short range.
An upper trough remains across much of the eastern Continental U.S. With no
significant short wave energy moving through the trough. At the surface...
dry high pressure builds in across the area Sat and sun. Guidance
blend shows dew points mixing out into the 50s across the area both
days. This combined with relatively warm middle level air will lead to
little to no cape each afternoon...resulting in very low potential
for deep moist convection. A remnant cold front boundary will be
close but south of the area providing little to no low level
convergence for the area. Therefore...have gone with a dry forecast.
Expect temperatures to be near to a little above normal through the period.
Long term /Monday through Thursday/...
as of 255 am Friday...guidance is in decent agreement through the
period. East Coast trough flattens through the period with westerly flow
developing across the area as heights rise. This allows a series of
short waves to move across or near the area. The dry high pressure
over the area slowly moderates then dissipates as a cold front drops
south toward the area. The cold front initially stalls...then moves
into the area Thursday as a low pressure area tracks from the Ohio Valley
off the middle Atlantic coast. The result is an increase in low level
moisture and instability through the period. The best forcing...and
resultant convection...will be Wednesday and Thursday...with a dry forecast Monday and
only isolated convection Tuesday across the mountains with the rising
heights and lingering high pressure Monday and Tuesday...temperatures will be
above normal. Temperatures slowly fall Wednesday and Thursday...but remain above
Aviation /08z Friday through Tuesday/...
at kclt...VFR. Convection will move south of the area overnight.
Guidance does not favor visibility or ceiling restrictions...but does favor
visibility restrictions in areas to teh north and S at dawn. Widns will
generlaly favor hte north...with only limited gust potential. Convection
is not expected during the day on firday in the drier air behind a
departing cold front.
Elsewhere...other than brief MVFR daybreak fog at kand...restrciions
are not favored at taf sites by model guidance...as drier air moves
in behind a departign ocld front. Widns will generally favor the
north...with Onley limited gusts.
Outlook...expecting generally dry and quiet weather through the
weekend with a gradual increase in chances for showers/thunderstorms
and restrictions for the start of the new work week.
07-13z 13-19z 19-01z 01-06z
kclt high 100% high 100% high 100% high 100%
kgsp high 100% high 100% high 100% high 100%
kavl high 100% 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 93% 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: (must be lower case)