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Area forecast discussion 
National Weather Service Greenville-Spartanburg SC
440 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.


Near term /through Monday/...
as of 440 PM edt: a typical mid Summer afternoon across the region
as temperatures hover in the mid/upper 90s, while heat index values
push near or just exceed the century mark. Given weaker subsidence
and upslope enhancement, convection continues to be focused along
the higher ridgetops as expected. That said, a few cells have tried
to get going along/south of i85, however with little Success given
the previously mentioned warm profiles. Thus for this update, only made
slight tweaks to pops/temps/dews to account for recent radar/ob

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


Short term /Monday night through Wednesday/...
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
Ohio 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


Long term /Wednesday night through Sunday/...
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 European model (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 Continental U.S. Thu with gradually lowering
heights across the east through the period as a broad 500 mb 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.


Aviation /21z Sunday through Friday/...
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 thunderstorms in the vicinity in the higher terrain and
nearer the better dewpoint gradient, respectively. Expect light SW
winds through the period, except for more northwest 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...

20-02z 02-08z 08-14z 14-18z
kclt high 100% high 100% high 100% high 100%
kgsp high 100% high 100% high 100% high 100%
kavl high 100% high 100% low 56% high 89%
khky high 100% high 100% high 91% high 100%
kgmu high 100% high 100% high 100% high 100%
kand high 100% high 100% high 95% 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:



records for 07-24

Maximum temperature min temperature
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

Records for 07-25

Maximum temperature min temperature
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


Gsp watches/warnings/advisories...


near term...cdg/hg
short term...jat
long term...sbk

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