Area Forecast Discussion
Issued by NWS Greer, SC

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FXUS62 KGSP 220555

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
155 AM EDT SUN MAY 22 2016

Dry high pressure builds into our region from the Mississippi and
Ohio valleys early this week as low pressure lingers over the
Mid-Atlantic. A moist southerly flow develops by mid week and
continues into the weekend.


As of 145 AM: CAA within the northwesterly low level flow will keep
things mixed, and patchy high-based stratocu will persist over
the eastern Piedmont early this morning. Along the TN/NC border,
upslope may also generate a few showers, but little to no QPF
is anticipated. Temps will fall slowly into the 50s by daybreak
Sunday. The forecast is largely unchanged, though we have refined
the extent of sky cover and the mountain PoPs based on consensus
of meso model runs.

Sunday...High pressure will build in across the the high
remains centered over the Mississippi River Valley. However...H5
closed low centered over VA will continue to support generally
moist NW flow across the west facing mtn slopes. Clouds and ISO
showers will remain in the forecast through Sunday. Elsewhere...dry
conditions with gusty NW winds will be featured in the forecast.
High temps should range from upper 60s within the mtn valleys to
mid to upper 70s across the upper Savannah River Valley.


As of 200 PM Saturday...the early part of next week will be
dominated by an upper low that should move off the Mid-Atlantic
coast Sunday night and Monday, then slowly rotate up to the New
England Coast on Tuesday. The western Carolinas will be under the N
flow part of the circulation into Tuesday, so other than some
lingering showers on the TN border Sunday evening, it should be dry.
The plume of better moisture rotating around the upper low is
expected to be just east of the fcst area on Monday. A few showers
may nick part of the NW Piedmont on Monday as some of the lingering
instability underneath the mid-level cool pool will be close by.
After that, think it should be dry as the low moves away Tuesday and
a flattening upper ridge builds in from the west Tuesday night.
Temps should moderate through the period...back to just below normal
on Monday...and then a few degrees above normal on Tuesday.


As of 235 PM Saturday, 500mb flow has a ridge axis from Mobile Al
to KY on Wednesday with surface high pressure shifting to the east
and off the east coast.  Moisture will be increasing slowly from the
west on south to southwesterly low level flow. Instability is rather
low Wed PM with 600 CAPE near Fontana Lake on the GFS model and
lower on ECMWF.  Moisture and instability will increase Thursday
into Friday as the much higher CAPEs remain near and west of
Mississippi River.  CAPE of 1000 to 1500 across our area Thursday PM
and even a bit higher Friday PM on GFS. Best CAPE on ECMWF on Thurs
PM with around 1600 late day.  Not much change in grids from
previous forecast. Low level flow becomes more SE going into next
weekend as ridge will be centered off the mid Atlantic Coast. This
would introduce an upslope component.

Max Temps a few degrees above normal with Highs in the 80s for all
elevations below 2500 feet. Mins mostly in the 60s.


At KCLT and elsewhere in the Piedmont: VFR at the TAF terminals,
though very early this morning a couple of more rural sites may see
brief vsby restrictions in fog, until drier air advects in closer
to dawn. Cold advective flow will promote mixing and gradient
remains sufficient to expect breezy/gusty conditions today. Winds
will prevail NW until this evening, when they will back a bit but
tend to go light/VRB. A few showers could develop over western NC
late this aftn but expected coverage is too sparse to mention in
TAFs at this point.

At KAVL: Moisture banking against the Appalachians will produce
low VFR cigs early this AM, which at times will lower to MVFR. A
TEMPO has been included accordingly.

Outlook: Mainly VFR conditions will prevail through early
week. Scattered afternoon SHRA/TSRA may return Wednesday, with
daily coverage increasing Thursday and Friday.

Confidence Table...

            06-12Z        12-18Z        18-24Z        00-06Z
KCLT       High 100%     High 100%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High  80%     High  99%     High 100%     High 100%
KHKY       High  92%     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 schedule TAF issuance flight rule category. Complete hourly
experimental aviation forecast consistency tables and ensemble forecasts
are available at the following link:




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