Scientific Forecaster Discussion
fxus62 kgsp 272353
Area forecast discussion
National Weather Service Greenville-Spartanburg SC
753 PM EDT Tue Jun 27 2017
dry and cool weather will continue through Wednesday. High pressure
moves off the East Coast on Thursday with warm and moist air moving
north from the Gulf through next weekend. This brings back the daily
chance of afternoon and evening showers and thunderstorms through
Near term /through Wednesday/...
745 PM update: fcst largely on track, with no major changes this
update. I did revise temp/dewpt trends thru about midnight, but
it is too early to tell if min temp fcst needs to be adjusted.
Surface high pressure centered over the western Ohio Valley
will continue to build southeastward tonight and settle over the
region. Diurnal clouds should dissipate with sunset and the higher
clouds will shift east this evening resulting in good radiational
cooling overnight. Settled weather will continue through Wednesday,
with low relative humidity through a very deep layer leading to mainly clear skies,
with just a few fair wx cumulus breaking out in the aftn. Southerly
flow and sunshine will help temps and humidity rebound slightly
vs. Tuesday's values, though still pleasantly below normal.
Short term /Wednesday night through Thursday night/...
as of 300 PM Tue: the incumbent sfc high will move offshore late
in the day Wednesday, with moist return flow continuing Wed night.
Thursday, a shortwave and increasing Gulf Coast moisture will move
in to the region. Weak isentropic upslope flow will bring a return
of diurnally-driven thunderstorms to the mountains and portions
of the upper Savannah valley on Thursday. While temperatures
will remain below seasonal normals, the increase in low level
moisture will bring humidity levels up with a return to more muggy
conditions. This Gulf moisture advection will continue to propagate
east and toward the Carolinas as the surface high pushes farther
off the coast. By Thursday night, should see lows pretty much near
seasonal normals with dewpoints continuing to rise.
Long term /Friday through Tuesday/...
as of 300 PM Tue: warm moist advection will continue through
Saturday, allowing for mainly diurnal convection. A weak front
will stall near the area this weekend, with another enhancement
to diurnal pops on Sunday. The front may push south of the area
by Monday as an upper ridge builds into the lower Mississippi
Valley. Expect near normal temperatures and a continued enhancement
in diurnal pops through the end of the period.
Aviation /00z Wednesday through Sunday/...
at kclt and elsewhere: VFR at all the taf sites with mainly sky clear
thru mid-morning. A pocket of low VFR clouds may remain trapped
under the inversion across parts of the upstate this evening. Winds
will remain northerly tonight, veering gradually to southerly by
midday as high pressure settles east of the region. Due to valley
channeling, however, kavl is expected to see their winds pick up
from the southeast soon after daybreak. A few low VFR cu will pop out
for the afternoon.
Outlook: moist, southerly return flow will develop around the
offshore ridge on Thursday. As a result, typical summertime
conditions will return by the end of the work week, with mainly
late afternoon-evening rain showers/thunderstorms and rain causing possible restrictions
through the weekend.
00-06z 06-12z 12-18z 18-00z
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 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: