Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 011056
AFDGSP

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
656 AM EDT Sat Oct 1 2016

.SYNOPSIS...
Dry southwest flow will linger across the region through this
weekend. Progressively warmer temperatures are on tap through early
next week. The path of tropical cyclone Matthew will be closely
watched as it tracks north over the western Atlantic next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 650 AM, valley fog/low stratus is a little more prevalent than
originally anticipated, so it has been expanded a bit in the
forecast, burning off rapidly by 9 AM. Another area of fog/low
stratus has snuck into our northwest NC Piedmont zones, so cloud
cover has been increased and visby reduced for the next couple of
hours there.

As of 320 AM, upper low centered near Cincinnati will wobble
steadily north into the Great Lakes region by the end of the period.
Heights/thicknesses will therefore begin to rise today. While the
I-77 corridor (finally solidly behind the surface front) should be a
little cooler than yesterday, much of the area should see maxes 1-2
degrees warmer than on Friday. However, it will once again be a dry
warmth, with dewpoints expected in the 40s in most locations this
afternoon. After a (slightly) unseasonably warm day, the dry air
mass should support min temps settling to right around climo Sunday
morning.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
At 240 AM Saturday: On Sunday, closed mid level low will slide over
the eastern Great Lakes, the trof axis is expected to extend down
across the mouth of the Mississippi River. Short range guidance
indicates that the forecast areas will remain under a band of dry
air, with high level moisture arriving late in the day. I will keep
PoPs in the single digits through the day. High temperatures are
forecast to range from the mid 70s within the mtn valleys to the low
to mid 80s east.

On Monday, a shallow mid level trof is expected to ripple over the
CWA during the daylight hours. Guidance indicates that the trof will
be accompanied by mid and high level moisture, I will increase sky
cover slightly over Sunday with single digit PoPs. High temperatures
should verify very close to values observed on Sunday.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 255 AM Saturday: The weakening of the western Atlantic
subtropical ridge and the approach of a mid level longwave trof over
the Great Plains should continue the northward track of TC Matthew
through next week. The 0z ECMWF has the center of Matthew a little
further east with a steady northward trek. The 0Z GFS shows Matthew
very close to the Atlantic shore, passing the Carolinas Friday -
Friday night. I will not change the extended range forecast much
based on the uncertainty of the track and timing of Matthew.
However, it does appear likely that sfc ridging sourced from a New
England high will develop on Tuesday and remain from much of the
work week. The forecast will feature a steady and light ENE wind
with generally partly cloudy sky conditions. A weak sfc front may
approach from the west by Friday night, guidance does not appear
very moist along and ahead of the front. Therefore, I will base the
timing and placement of schc showers to the favored areas near the
east facing slopes and along and east of I-77. Otherwise,
temperatures should favor values 3-5 degrees above normal.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere (except KHKY/mtn valleys): relatively dry air
is expected to result in VFR/mostly SKC conditions across the
terminal forecast area through the next 24 hours. Light/vrbl or calm
winds are expected to become light S/SW at most terminals by around
noon.

At KHKY/mtn valleys: fog and low stratus has developed in the
valleys west and north of KAVL, but KAVL is expected to remain VFR
through at least this evening. KHKY recently picked up a brief
period of VLIFR, but quickly lifted to MVFR. This is usually an
indication of ground fog rather than "the real thing." Will start
the period with MVFR visby followed by rapid improvement to VFR. Mtn
valley fog/low stratus should return tonight, esp for the valleys
west of KAVL.

Outlook: VFR conditions are expected in most places through early
next week as dry high pressure remains over the area. However,
morning restrictions in the mtn valleys will likely continue.

Confidence Table...

            11-17Z        17-23Z        23-05Z        05-06Z
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 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:

www.weather.gov/gsp/aviation

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.

&&

$$
SYNOPSIS...NED
NEAR TERM...JDL
SHORT TERM...NED
LONG TERM...NED
AVIATION...JDL


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