Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
202 PM EDT TUE AUG 2 2016

.SYNOPSIS...
Chances for showers and thunderstorms will remain elevated through
midweek as a cold front slides into the region.  Although a wedge of
high pressure extends into the region through late week, moisture is
expected to remain in place thereby keeping precipitation chances
elevated. Another and perhaps more established cold front will push
into the region next weekend allowing for increased precipitation
chances regionwide.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 2 PM: Latest visible satellite indicated very little CU in the
wake of dissipated morning Piedmont stratus. Upstream, mtns are
covered with widespread developed CU congestus and CBs. Latest sfc
analysis indicated that most of the foothills and Piedmont remained
under 2500-3000 J/kg of CAPE, with no analyzed CIN. I will expect
showers and thunderstorms to slide off the high terrain, with the
initial line pushing east by 22z. SCT to NUM cells may develop
within the wake of the line of TSRA, dissipate one to two hours
after sunset. The calm winds and dissipating debris clouds will
favor the development of mtn valley fog late tonight. Llvl weak
upslope flow should support SHRA/TSRA along the east facing slopes
by mid day Wed. I will update the forecast to adjust PoPs and sky,
lower high temps by a few degrees.

As of 945 AM: recent visible satellite images indicate that morning
stratus has not started to dissipate across the foothills and
Piedmont. Latest observations indicate that cloud bases have begun
to lift. Based on satellite trends and recent MOS, I will update the
forecast to indicate the stratus holding on until noon. In addition,
I will update the forecast to adjust morning temps a little cooler
under the widespread cloud cover. PoPs still appear on track,
comparing to recent runs of the HRRR.

As of 650 AM, mountain valley fog and patchy low clouds and fog
outside of the mountains will dissipate after daybreak.

Otherwise, a convective complex moving across TN will move into the
mountains this morning. This activity may hold together at it
crosses the mountains. This short wave then crosses the area
in the NW flow aloft and will provide a focus for convection across
the area today. A weak surface frontal boundary will drop into the
area today as well providing low level forcing. CAM guidance shows
convection developing across the mountains early in response to the
forcing, then sliding SE across the CWFA through the afternoon and
early evening. All this suggests a favorable environment for
convection, so have band of likely PoP moving across the area.
Instability, DCAPE, and shear will remain weak indicating a low
chance of severe storms today. That said, cannot rule out an
isolated severe downburst. The bigger concern will be heavy
rainfall. PW values increase to over 2 inches today. With the
numerous convection and slow moving storms, isolated areas of
excessive rainfall leading to flooding is possible. Highs will be a
little above normal today.

The frontal boundary stalls across the area tonight. A wave of low
pressure forms along the front somewhere over the CWFA. In addition,
high pressure will build in from the NE in a damming like pattern.
The easterly flow around these features will increase through the
night bringing in moisture and upslope flow. The guidance differs in
the exact location of strongest flow and greatest moisture.
Therefore, drop PoP overnight to slight chance with the axis along
and near the NC Blue Ridge. Expect low clouds to develop across this
area as well, with patchy fog. Lows will be a little above normal.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 230 AM EDT Tuesday:  The short term fcst period kicks off on
Wednesday morning amidst a broad H5 anticyclone centered over the
southern CONUS while another region of shortwave ridging prevails
over the northeast states.  At the surface, high pressure will
remain anchored beneath the a fore mentioned shortwave ridge aloft
over New England, extending southward in lee of the central/southern
Appalachians.  Moisture along an intruding frontal axis is to remain
draped across the Carolinas on Wednesday, further compounded by
developing easterly moisture advection through the remainder of the
period.  As a result, pwats approaching/exceeding 2-2.5in are fcst,
especially along and east of the Blue Ridge.  Given modest
instability out ahead, convection is expected to accompany the
intruding front as it slides south across the western Carolinas and
northeast GA on Wednesday.  As for Thursday, given the developing
easterly low level upsloping flow, convection is expected to
initiate along the eastern escarpment with more thermodynamically
forced convection possible across the low terrain.  The nature of
the weak flow pattern, highlighted by nw flow aloft atop easterly
flow in the low levels does present favorable conditions for
anchoring cells and thus increased chances for localized heavy
rainfall.

Therefore the fcst each day will feature solid chance
pops across the low terrain increasing to low end likely levels
along the Blue Ridge.  Temperatures across the region will generally
be at or below normal each day, with the exception being on
Wednesday across the upper Savannah River valley where differential
heating could allow maxes to push to just above normal before more
abundant sky cover advects in.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 300 AM EDT Tuesday:  The medium range fcst period initializes
on Friday morning amidst persistent broad/elongated H5 ridging
across much of the southern CONUS, while shortwave ridging over
the northeast finally advects eastward.  As a consequence, the
surface pattern will modify on Friday as the New England high
moves out allowing for the return to dominance of the subtropical
ridge yielding southerly veered waa across the southeast states.
Likewise, a potent H5 trof over Ontario/Quebec will slide east with
an associated surface front stretching southward across the Great
Lakes, moving into the OH valley early on Saturday.  Said front is
progged to slide into the southern Appalachians Saturday evening,
pushing through northeast GA and the western Carolinas on Sunday.
At that point the front looks to slow/stall across the Midlands
while broad surface high pressure builds over the Great Lakes
toward the end of the period.

All said, the fcst features chance pops regionwide on Friday
with low end likely levels favored along the Blue Ridge.  Pops on
Saturday are generally a category lower as diurnal convection is
favored, with the exception of any prefrontal convection moving
into the NC high terrain late in the day.  From that point, pops
will increase overnight into/through Sunday to solid chances as the
front slowly intrudes, lingering near those levels through Monday
as the front remains stalled in the vicinity.  Temperatures through
the weekend will warm back to above normal levels, dropping a few
degrees on Monday behind the front.

&&

.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Latest visible satellite indicated very
little CU in the wake of dissipated morning Piedmont stratus.
Upstream, mtns are covered with widespread developed CU congestus
and CBs. Latest sfc analysis indicated that most of the foothills
and Piedmont remained under 2500-3000 J/kg of CAPE, with no analyzed
CIN. I will expect showers and thunderstorms to slide off the high
terrain, with the initial line pushing east by 22z. SCT to NUM cells
may develop within the wake of the line of TSRA, dissipate one to
two hours after sunset. The calm winds and dissipating debris clouds
will favor the development of mtn valley fog late tonight. Llvl weak
upslope flow should support SHRA/TSRA along the east facing slopes
by mid day Wed.

I will indicate a TEMPO for most sites to indicate TSRA between 20z
to 24z. KAVL should see IFR to VLIFR ceilings and vis, high lighted
with a FM group at 10z and a TEMPO from 10z to 13z.

Outlook: Moisture will increase on easterly flow from mid to late
week with associated showers and thunderstorms developing -
especially in the afternoon and evening. Restrictions will be
possible with any afternoon/evening convection as well as each
morning in the mountain valleys where fog and low stratus are likely.

Confidence Table...

            18-24Z        00-06Z        06-12Z        12-18Z
KCLT       High  93%     High 100%     High  82%     High  94%
KGSP       High 100%     High 100%     High  91%     High  94%
KAVL       High  92%     High  83%     Med   67%     Med   79%
KHKY       High 100%     High  97%     Med   64%     Med   77%
KGMU       High 100%     High 100%     High 100%     High 100%
KAND       High 100%     High 100%     High  80%     High  94%

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...CDG
NEAR TERM...NED/RWH
SHORT TERM...CDG
LONG TERM...CDG
AVIATION...NED

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
454 AM EDT TUE AUG 2 2016

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-030900-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-CATAWBA-
ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-
HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION-
CALDWELL MOUNTAINS-GREATER CALDWELL-BURKE MOUNTAINS-GREATER BURKE-
MCDOWELL MOUNTAINS-EASTERN MCDOWELL-RUTHERFORD MOUNTAINS-
GREATER RUTHERFORD-POLK MOUNTAINS-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-CHESTER-GREENWOOD-
454 AM EDT TUE AUG 2 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
MOVE ACROSS THE REGION THIS AFTERNOON AND EVENING. AN ISOLATED
STRONG TO SEVERE THUNDERSTORM CANNOT BE RULED OUT WITH THE PRIMARY
THREAT BEING DAMAGING WINDS. ADDITIONALLY...ELEVATED MOISTURE IN
THE ATMOSPHERE WILL PRESENT THE THREAT FOR HEAVY RAINFALL AMONGST
ANY OF THE STRONGER STORMS LEADING TO THE POTENTIAL FOR ISOLATED
FLASH FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY.

..WEDNESDAY...HEAVY RAIN POSSIBLE. ATMOSPHERIC MOISTURE WILL
CONTINUE TO INCREASE ON WEDNESDAY LEADING TO AN ENHANCED THREAT OF
HEAVY RAINFALL THAT COULD LEAD TO ISOLATED FLASH FLOODING.
THIS THREAT OVERSPREADS THE ENTIRE REGION...HOWEVER THE GREATEST
CHANCES FOR MODERATE TO HEAVY RAINFALL WILL RESIDE ALONG THE BLUE
RIDGE WHERE EASTERLY UPSLOPE FLOW IS EXPECTED.
..THURSDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..FRIDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SATURDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..SUNDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
..MONDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

CDG

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1254 PM EDT TUE AUG 2 2016

NCZ033-501-021745-
CALDWELL MOUNTAINS NC-AVERY NC-
1254 PM EDT TUE AUG 2 2016

...A THUNDERSTORM WITH TORRENTIAL RAINFALL WILL IMPACT NORTHWESTERN
CALDWELL AND SOUTHEASTERN AVERY COUNTIES UNTIL 145 PM EDT...

AT 1253 PM EDT...DOPPLER RADAR WAS TRACKING A THUNDERSTORM WITH
TORRENTIAL RAINFALL 9 MILES SOUTHEAST OF NEWLAND...OR 5 MILES
SOUTHEAST OF B.R. PARKWAY-LINVILLE FALLS TO GRANDFATHER. THIS STORM
WAS NEARLY STATIONARY.

LOCATIONS TO BE IMPACTED INCLUDE...
GRANDFATHER MOUNTAIN...GRANDFATHER MOUNTAIN STATE PARK...B.R.
PARKWAY-LINVILLE FALLS TO GRANDFATHER...UPTON...EDGEMONT...GLOBE AND
COLLETTSVILLE.

TORRENTIAL RAINFALL RATES UP TO 3 INCHES PER HOUR WILL BE POSSIBLE IN
THESE AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL MAY FLOOD AREAS WITH POOR DRAINAGE...SUCH AS
DITCHES AND UNDERPASSES. AVOID THESE AREAS AND DO NOT CROSS FLOODED
ROADS. WATER LEVELS OF SMALL STREAMS MAY ALSO RISE RAPIDLY. SEEK
HIGHER GROUND IF THREATENED BY FLOOD WATERS. DO NOT DRIVE ACROSS
FLOODED ROADS.

&&

LAT...LON 3611 8181 3612 8175 3608 8156 3593 8166
      3589 8173 3593 8175 3593 8178 3595 8178
      3595 8180 3597 8182 3598 8187 3600 8189
TIME...MOT...LOC 1653Z 297DEG 3KT 3602 8178

ARK

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
233 PM EDT TUE AUG 2 2016

NCZ505>508-021900-
RUTHERFORD MOUNTAINS NC-GREATER RUTHERFORD NC-MCDOWELL MOUNTAINS NC-
EASTERN MCDOWELL NC-
233 PM EDT TUE AUG 2 2016

...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT NORTHERN
RUTHERFORD AND SOUTHEASTERN MCDOWELL COUNTIES UNTIL 300 PM EDT...

AT 233 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM WITH
INTENSE LIGHTNING 7 MILES SOUTHWEST OF MARION...OR 6 MILES SOUTHEAST
OF OLD FORT...MOVING SOUTHEAST AT 25 MPH.

LOCATIONS TO BE IMPACTED INCLUDE... FOREST
CITY...RUTHERFORDTON...MARION...SPINDALE...BOSTIC...SUNSHINE...FERO..
.
SUGAR HILL...THERMAL CITY AND SHINGLE HOLLOW.

IN ADDITION TO INTENSE LIGHTNING...WIND GUSTS UP TO 40 MPH AND VERY
HEAVY RAINFALL RATES UP TO 2 INCHES PER HOUR WILL BE POSSIBLE IN
THESE AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

GUSTY WINDS CAN BLOW DOWN TREES THAT ARE DEAD...OR THAT HAVE WEAKENED
ROOT SYSTEMS. OUTDOOR FURNITURE AND SIMILAR ITEMS CAN BE TOSSED
AROUND IF NOT ANCHORED. SEEK SHELTER INDOORS.

FREQUENT LIGHTNING IS OCCURRING WITH THIS STORM. IF OUTDOORS...TRY TO
GET INDOORS OR INTO A HARD TOPPED VEHICLE. OTHERWISE...STAY AWAY FROM
OPEN AREAS AND ISOLATED HIGH OBJECTS SUCH AS TREES. WHEN INDOORS...
STAY AWAY FROM WINDOWS AND DOORS AND AVOID USING WIRED ELECTRONIC
DEVICES. DO NOT TAKE A SHOWER OR BATH. TRY TO UNPLUG UNNECESSARY
APPLIANCES BEFORE THE STORM APPROACHES.

&&

LAT...LON 3551 8169 3547 8170 3528 8187 3556 8221
      3570 8208
TIME...MOT...LOC 1833Z 308DEG 26KT 3559 8208

07