Special Weather Statement, NWS Greenville-Spartanburg, SC

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
732 PM EDT Tue Mar 21 2017

.SYNOPSIS...
A cold front will move through the area later tonight, increasing
the chances for widespread showers and thunderstorms. A few of the
thunderstorms could be severe. Cooler air will return behind the
front to end the work week before another frontal system approaches
the area next weekend.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
730 PM EDT Update...Strong/severe storms with big hail arnd the GSP
area tonight. Reports of car windows smashed and golf ball size or
greater hail. These storms have trained down from the escarpment of
nrn G-ville Co and there are some concerns with high water levels
across local streams as well. Will investigate for possible flood
advisories or SPSs. Strong h5 s/w noted crossing into nrn GA and ern
TN attm will track across the CWFA late tonight thru the early
morning hrs. More strong to severe storms are probable with this
feature producing damaging winds and large hail once again.

500 PM EDT Update...A couple Upstate svr storms are beginning to
break the thermal cap and slowly advance south ahead of a sfc bndry.
Expect isol stg/svr activity to remain across NE GA and the Upstate
through 00z. An advancing acute h5 s/w will enhance activity from
the west and cross the watch area into the late evening. The watch
may need to be expanded east later on.

As of 215 PM: A nearly stationary front remains across the northern
tier of NC and TN attm; it is difficult to pinpoint the front in
many areas, but it is clear VA and KY are north of the front. At any
rate, an amplified upper ridge will move into the Plains states this
evening, and in response high pressure will shift into the Great
Lakes region, driving the front south through our area tonight.

This afternoon, south of the front, warm and seasonably humid
conditions will be present. Mid-level lapse rates are rather strong,
and accordingly forecast CAPE values range from 750-1000 J/kg over
the NE CWFA to nearly 2000 J/kg over parts of SW NC and NE GA. Most
prog soundings continue to feature at least a small cap until around
21z, and this is reflected in reflectivity/QPF output from the CAMs,
which is minimal until then. 0-6km bulk shear values will be on the
order of 30-35 kt around peak heating, and we continue to expect
storms to organize to some degree. SPC has outlined an Enhanced
Risk centered to our west, but extending into a small portion
of our northeast GA territory; this is surrounded by a narrow
Slight Risk region. At least the Enhanced area will receive the
effects of a compact shortwave during the late afternoon hours,
and models are a bit more aggressive in pushing the front south
thru TN than they are over our area. Also of note, meso model runs
have tended to show a forward-propagating cluster developing in the
Tennessee Valley and tracking east this evening. This may present
a secondary threat to our western areas in addition to that posed
by the greater afternoon instability. Our entire CWFA continues
to be included in a Marginal Risk where the threats appear largely
the same, but the coverage will be lower.

Remnant stratiform precip associated with the decayed MCS is
expected to cross the area overnight, perhaps with a few isolated
rumbles of thunder but otherwise just light rainfall. With any
broad frontal boundary progged to push through in the early morning
hours, I am somewhat cautious about advertising a total "scouring"
of low-level moisture. However, essentially all guidance sources,
including MOS, depict the low clouds pushing out by daybreak, and
cooler and drier conditions lasting thru Wednesday. GFS still tries
to develop a little instability over NE GA, but currently this looks
to be an outlier. All precip mention has been dropped. Sunshine
and gradual downsloping should permit high temps near normal.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
As of 2pm EDT Tuesday:  GFS and EC models in good agreement on
synoptic pattern transitioning Wednesday evening to Friday from
northwesterly flow with dry, cool low-level advection to a ridge
centered over the CWA by Friday afternoon.  Dewpoints begin to
improve Friday afternoon as surface high pressure center moves
eastward off the coast and low-level flow veers from easterly to
southeasterly, beginning the southeasterly advection of
moisture into the area.

With a dry boundary layer and ridging aloft, there will be little
chance for precipitation Wednesday night through Friday, with only
an outside chance for some orographic-related showers in far western
parts of the CWA.  Main issue will be chances for frost/freeze
Thursday and Friday mornings.  Current lows show freeze possible
with frost likely for western parts of North Carolina, with less
potential for Piedmont areas.  Drier air and few clouds northeast of GSP
leads to lower forecast lows to the northeast with CLT possibly
reaching low to mid 30s Thursday morning and mid to upper 30s Friday
morning.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
As of 205 PM EDT Tuesday: the medium range fcst picks up at 00z on
Saturday with upper ridging centered over the SE CONUS and a
southern stream closed upper low moving across the southern plains.
Over the next 24 to 48 hrs, the low will approach the fcst area and
as it does, it will lift northward and up over the ridge. As it
does, it's also expected to deamplify and open up as it rides up the
ridge. As we move into early next week, another H5 shortwave will
approach the CWFA from the west. It also appears to deamplify as it
approaches the CWFA.

At the sfc, broad high pressure will be centered well offshore with
moist SLY flow over the region. By early Sunday, a vigorous low will
lift NE towards the Great Lakes and push a moist warm front over the
CWFA. The cold front associated with the low, looks like it will
largely washout as it lays across our northern fringe early Monday.
As we move into Tuesday, another sfc low follows a similar track
towards the Great Lakes and brings another cold front to our
doorstep by the end of the period. As for the sensible wx, POPs
steadily ramp up from the west on Sat with likely POPs over half of
the CWFA by Sunday morning. Some drying is expected on Monday,
however POPs increase again on Tuesday with the approach of the next
frontal system. Temps start out above normal and remain above normal
thru the period.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
At KCLT and elsewhere: Showers and strong to severe thunderstorms will cross
the SC sites as well as KCLT thru the overnight. Large hail and
damaging winds could occur at any site thru 09z. CIGS and VSBY are
generally remaining in the VFR range outside of the storms...with
MVFR/IFR conds and erratic gusty winds underneath the individual
cells. The mtn sites should remain out of the strong activity with
isol general tstms possible overnight. Skies clear up around
daybreak with winds shifting n/ly to nne/ly.

Outlook: Low level moisture starts to lift back north and deepen by
Thursday, keeping chances of showers and low cigs into the weekend.

Confidence Table...

            23-05Z        05-11Z        11-17Z        17-18Z
KCLT       High 100%     High  89%     High 100%     High 100%
KGSP       High 100%     High 100%     High 100%     High 100%
KAVL       High 100%     High  94%     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...JPT
NEAR TERM...SBK/Wimberley
SHORT TERM...WJM
LONG TERM...JPT
AVIATION...SBK

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
337 PM EDT Tue Mar 21 2017

GAZ010-017-018-026-028-029-NCZ051-058-059-062>064-SCZ001>007-010>013-
019-221945-
Rabun-Habersham-Stephens-Franklin-Hart-Elbert-Swain-Graham-
Northern Jackson-Macon-Southern Jackson-Transylvania-
Oconee Mountains-Pickens Mountains-Greenville Mountains-
Greater Oconee-Greater Pickens-Greater Greenville-Spartanburg-
Anderson-Abbeville-Laurens-Union-Greenwood-
337 PM EDT Tue Mar 21 2017

...SEVERE THUNDERSTORM WATCH 76 IN EFFECT UNTIL 11 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for northeast Georgia, western
North Carolina and upstate South Carolina.

.DAY ONE...This Afternoon and Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Severe Thunderstorm Watch.

Showers and thunderstorms develop across the area this afternoon and
continue into the evening. A few of these storms could become severe
producing damaging winds and large hail.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

..Wednesday...No hazardous weather is expected at this time.
..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.

NCZ033-048>050-052-053-065-501-503-505-507-509-221945-
Avery-Madison-Yancey-Mitchell-Haywood-Buncombe-Henderson-
Caldwell Mountains-Burke Mountains-McDowell Mountains-
Rutherford Mountains-Polk Mountains-
337 PM EDT Tue Mar 21 2017

This Hazardous Weather Outlook is for western North Carolina.

.DAY ONE...This Afternoon and Tonight.

Showers and thunderstorms develop across the area this afternoon and
continue into the evening. A few of these storms could become severe
producing damaging winds and large hail.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

..Wednesday...No hazardous weather is expected at this time.
..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.

SCZ008-221945-
Cherokee-
337 PM EDT Tue Mar 21 2017

...SEVERE THUNDERSTORM WATCH 76 IN EFFECT UNTIL 11 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for upstate South Carolina.

.DAY ONE...This Afternoon and Tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Severe Thunderstorm Watch.

Showers and thunderstorms develop across the area this afternoon and
continue into the evening. A few of these storms could become severe
producing damaging winds and large hail.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

..Wednesday...No hazardous weather is expected at this time.
..Thursday...Frost/freeze possible. Cold high pressure builds into
the area with temperatures falling into the lower to mid 30s. This
will create the potential for frosty or freezing conditions.
..Friday...Frost/freeze possible. Cold high pressure remains over
the area with temperatures in the mid 30s. This will create the
potential for frosty conditions.
..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.

NCZ035>037-056-057-068>072-082-502-504-506-508-510-SCZ009-014-221945-
Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln-Gaston-
Mecklenburg-Cabarrus-Union-Greater Caldwell-Greater Burke-
Eastern McDowell-Greater Rutherford-Eastern Polk-York-Chester-
337 PM EDT Tue Mar 21 2017

This Hazardous Weather Outlook is for piedmont North Carolina,
western North Carolina and upstate South Carolina.

.DAY ONE...This Afternoon and Tonight.

Showers and thunderstorms develop across the area this afternoon and
continue into the evening. A few of these storms could become severe
producing damaging winds and large hail.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday.

..Wednesday...No hazardous weather is expected at this time.
..Thursday...Frost/freeze possible. Cold high pressure builds into
the area with temperatures falling into the lower to mid 30s. This
will create the potential for frosty or freezing conditions.
..Friday...Frost/freeze possible. Cold high pressure remains over
the area with temperatures in the mid 30s. This will create the
potential for frosty conditions.
..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.

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
901 PM EDT TUE MAR 21 2017

GAZ017-018-026-028-029-220130-
Elbert GA-Hart GA-Franklin GA-Stephens GA-Habersham GA-
901 PM EDT TUE MAR 21 2017

...STRONG THUNDERSTORMS WILL IMPACT FRANKLIN...STEPHENS...ELBERT...
SOUTHEASTERN HABERSHAM AND HART COUNTIES UNTIL 930 PM EDT...

At 900 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 6 miles southeast of Clarkesville to 5 miles west
of Jefferson, and moving southeast at 35 mph.

Locations to be impacted include...
Toccoa, Elberton, Hartwell, Carnesville, Royston, Reed Creek,
Lavonia, Gumlog, Bowman and Canon.

Wind gusts up to 40 mph, half inch hail and very heavy rainfall rates
up to 2 inches per hour will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

&&

A severe thunderstorm watch remains in effect until 1100 PM EDT for
northeastern Georgia...and Upstate South Carolina.

LAT...LON 3401 8294 3417 8310 3423 8308 3427 8312
      3424 8317 3426 8330 3423 8335 3433 8339
      3445 8339 3449 8349 3460 8344 3465 8328
      3461 8316 3448 8304 3448 8288 3437 8284
      3427 8275 3415 8272 3409 8264 3399 8258
TIME...MOT...LOC 0100Z 315DEG 44KT 3453 8347 3411 8366

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
912 PM EDT TUE MAR 21 2017

NCZ048-051-052-059-062>065-220145-
Transylvania NC-Haywood NC-Henderson NC-Swain NC-Southern Jackson NC-
Madison NC-Northern Jackson NC-Macon NC-
912 PM EDT TUE MAR 21 2017

...STRONG THUNDERSTORMS WILL IMPACT EASTERN MACON...TRANSYLVANIA...
JACKSON...SOUTH CENTRAL MADISON...SOUTHEASTERN SWAIN AND HAYWOOD
COUNTIES UNTIL 945 PM EDT...

At 911 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 10 miles northeast of Bryson City to near
Franklin to 4 miles southeast of Clayton, and moving east at 35 mph.

Locations to be impacted include...
Brevard, Franklin, Sylva, Waynesville, Cherokee, Canton, Cullowhee,
Lake Junaluska, Clyde and Highlands.

Wind gusts up to 40 mph will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

&&

A severe thunderstorm watch remains in effect until 1100 PM EDT for
northeastern Georgia...western North Carolina...and Upstate South
Carolina.

LAT...LON 3559 8335 3574 8271 3572 8271 3569 8281
      3570 8285 3567 8289 3562 8285 3557 8277
      3547 8280 3544 8278 3542 8274 3545 8269
      3526 8267 3510 8270 3507 8275 3509 8279
      3500 8311 3500 8343 3516 8346
TIME...MOT...LOC 0111Z 260DEG 38KT 3553 8332 3518 8340 3483 8335

HG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
914 PM EDT TUE MAR 21 2017

GAZ010-SCZ001-002-004-005-010-220145-
Rabun GA-Greater Pickens SC-Pickens Mountains SC-Greater Oconee SC-
Anderson SC-Oconee Mountains SC-
914 PM EDT TUE MAR 21 2017

...STRONG THUNDERSTORMS WILL IMPACT NORTHEASTERN RABUN...ANDERSON...
PICKENS AND OCONEE COUNTIES UNTIL 945 PM EDT...

At 913 PM EDT, Doppler radar indicated strong thunderstorms along a
line extending from 15 miles north of Walhalla to 11 miles north of
Toccoa to 7 miles northeast of Homer, and moving east at 70 mph.

Locations to be impacted include...
Anderson, Easley, Clemson, Seneca, Walhalla, Pickens, Homeland Park,
Powdersville, Piedmont and Central.

Wind gusts up to 40 mph will be possible in these areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

The combination of gusty winds and saturated soil conditions will
cause scattered trees and power lines to fall. Seek shelter inside an
interior room.

&&

A severe thunderstorm watch remains in effect until 1100 PM EDT for
northeastern Georgia...western North Carolina...and Upstate South
Carolina.

LAT...LON 3428 8277 3434 8279 3437 8284 3448 8288
      3448 8304 3461 8316 3461 8323 3466 8330
      3500 8314 3506 8289 3507 8277 3505 8274
      3507 8257 3501 8260 3501 8254 3498 8255
      3478 8245 3468 8246 3430 8260 3427 8264
TIME...MOT...LOC 0113Z 269DEG 59KT 3497 8316 3474 8328 3440 8341

HG

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
919 PM EDT TUE MAR 21 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0830 PM     TSTM WND DMG     ROBBINSVILLE            35.32N 83.81W
03/21/2017                   GRAHAM             NC   911 CALL CENTER

            NUMEROUS TREES DOWN ACROSS GRAHAM COUNTY

&&

LVISIN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
930 PM EDT TUE MAR 21 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0930 PM     HAIL             4 WSW SALISBURY         35.64N 80.55W
03/21/2017  E1.00 INCH       ROWAN              NC   TRAINED SPOTTER

&&

KRENTZ

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
940 PM EDT TUE MAR 21 2017

NCZ048-051>053-059-063>065-507-509-510-SCZ002>007-010-220245-
Buncombe NC-Transylvania NC-Swain NC-Rutherford Mountains NC-
Madison NC-Eastern Polk NC-Northern Jackson NC-Haywood NC-
Henderson NC-Polk Mountains NC-Southern Jackson NC-
Greater Pickens SC-Greater Oconee SC-Pickens Mountains SC-
Anderson SC-Greenville Mountains SC-Spartanburg SC-
Greater Greenville SC-
940 PM EDT TUE MAR 21 2017

...THUNDERSTORM OUTFLOWS WILL BRING VERY GUSTY WINDS TO THE CENTRAL
AND SOUTHERN MOUNTAINS OF WESTERN NORTH CAROLINA AS WELL AS THE
NORTHERN UPSTATE OF SOUTH CAROLINA THROUGH 1045 PM EDT...

At 938 PM EDT, Doppler radar indicated a line of showers and
thunderstorms extending from 15 miles northwest of Waynesville to 10
miles southwest of Brevard to near Seneca, and moving east at 20
mph. This line was producing a persistent outflow of 40 mph wind
gusts as it moves east.

Locations to be impacted include...
Greenville Downtown, Downtown Asheville, Easley, Clemson,
Hendersonville, Brevard, Pickens, Waynesville, Columbus and Marshall.

Wind gusts up to 45 mph will be possible in these areas.

A severe thunderstorm watch remains in effect until 1100 PM EDT for
western North Carolina...and Upstate South Carolina.

LAT...LON 3597 8261 3595 8256 3598 8251 3594 8249
      3591 8249 3590 8246 3522 8211 3483 8229
      3455 8298 3479 8293 3481 8290 3492 8291
      3505 8288 3567 8327 3579 8303 3578 8299
      3584 8293 3599 8261
TIME...MOT...LOC 0138Z 226DEG 17KT 3566 8317 3511 8283 3468 8291

HG