Hail and Damaging Wind in Georgia, April 27 to 29, 2017

Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
302 PM EDT Thu Apr 27 2017

.SYNOPSIS...
Warm and humid high pressure will build in through the end of the
work week. A front will move into the area late this weekend,
increasing chances for showers and thunderstorms on Sunday. Another
front will approach by the middle of next week.

&&

.NEAR TERM /THROUGH FRIDAY/...
As of 3pm EDT Thursday:  Broad Central CONUS upper trough is
ejecting a shortwave/frontal system through the southeast this
afternoon and evening.  Front weakens and eventually washes-out as
it passes over the southern Appalachians.  Ahead of the front, a
round of showers and thunderstorms is anticipated this afternoon and
evening.  Instability is limited by cloud cover, but MUCAPE
currently exceeds 1000 j/kg over the Piedmont to 500 j/kg in the
higher terrain.  Effective deep layer shear is also 40 to 50 kts,
giving some potential for organized convection and severe weather,
with the best opportunity for severe near peak heating from about 4
to 8pm; with showers lingering through midnight.  Significantly
better shear/instability combination exist south and west of the
area, but some severe wind or possibly a weak tornado are possible
this afternoon, especially in the Piedmont.

Main front with this system makes only gradual progress
southeastward across the CWA and front largely dissipates Friday
afternoon with little in the way of dry or cold advection in the
wake of the system.  Midlevel ridging also occurs in the wake of
today's system as Central CONUS trough digs more into the Southwest.
Consequently, Friday's temperatures will warm into the 80s with more
sensible humidity than we have seen in recent months. Wet ground and
any new precipitation along with elevated dewpoints will give a good
chance for fog Friday morning at some level, especially in sheltered
areas with reduced wind.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
As of 225 PM Thursday: the short term fcst picks up at 00z on
Saturday with steep upper ridging building over the region as an
equally steep upper trof digs down across the extreme SW CONUS. The
upper ridge is expected to slowly drift eastward thru the period,
yet it should remain largely in place over our region. At the sfc,
the Bermuda High will keep warm southerly flow over the region thru
the period with the next frontal system approaching the fcst area by
the end of the short term late Sunday. The sensible fcst will be
marked by well above normal temps and high dewpts in the 60s. Better
cloud cover on Sun should keep temps about a category cooler than
Sat. These conditions should provide ample instability each day for
diurnally driven tsra.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
As of 235 PM EDT Thursday...the extended fcst picks up at 00z on
Monday with steep upper ridging centered just off the Atlantic Coast
and a deep upper trof moving across the Southern Plains and into the
Mississippi River Valley. As the trof approaches our area, it is
expected to lift NE and up over the Great Lakes by early Tuesday.
Over the next 24 hrs or so, the trof lifts farther NE over southern
Ontario/Quebec as heights begin to recover over the southeast.
During the remainder of the period, a southern stream upper trof
amplifies over the ArkLaTex region and encroaches upon our fcst area
by the end of the period late Thursday. At the sfc, warm sly flow
will persist across the area into early Monday. The next frontal
system will move thru the fcst area sometime Monday morning to
Monday afternoon bringing with it a good chance for widespread
showers and ts. Drying high pressure will overspread the area in the
front's wake on Tues with another frontal system approaching the
CWFA by the end of the period on Thurs.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
At KCLT and elsewhere:  Main issue will be progress of a round of
thunderstorms this afternoon and evening.  Progress of system and
approach of front from the west has reduced CIGs to as low as 20kft
in areas without precip., and down below 10kft in areas with.
Current widely scattered showers will give way to some -TSRA this afternoon
with the heaviest activity expected from 20Z to 24Z and lingering
scattered showers after that.  Front with this system is quite weak,
and winds outside of areas with convection will be weak, with light
and variable winds on Friday.  Continued moist low-levels is
expected to lead to fog in the morning, especially in areas with
less wind.

Outlook: High pressure on Friday should lead to widespread VFR with
more diurnally-based showers and thunderstorms possible Saturday and
Sunday.

Confidence Table...

            19-01Z        01-07Z        07-13Z        13-18Z
KCLT       High  92%     Med   70%     Med   61%     High  84%
KGSP       High  84%     Med   61%     Med   65%     Med   77%
KAVL       Low   49%     High  99%     High  91%     High  95%
KHKY       Med   74%     Low   56%     Med   69%     Med   78%
KGMU       High  82%     Low   59%     Med   65%     Med   76%
KAND       High  80%     Low   58%     Med   61%     High  83%

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...LEV
NEAR TERM...WJM
SHORT TERM...JPT
LONG TERM...JPT
AVIATION...WJM

Hazardous Weather Outlook
National Weather Service Greenville-Spartanburg SC
403 PM EDT Thu Apr 27 2017

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-282015-
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-
403 PM EDT Thu Apr 27 2017

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

.DAY ONE...This Afternoon and Tonight.

A cold front will continue to push through the area late this afternoon
and evening producing scattered showers and thunderstorms. Conditions
will be favorable for a few of these storms to produce damaging winds
and large hail. In addition, an isolated tornado cannot be ruled out
across the piedmont and foothills.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

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

.SPOTTER INFORMATION STATEMENT...

Skywarn spotters are requested to forward any reports of large
hail...damaging winds...tornadoes or flash flooding to our office.

JPT

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
448 PM EDT THU APR 27 2017

GAZ010-NCZ059-062>064-272130-
Rabun GA-Transylvania NC-Southern Jackson NC-Northern Jackson NC-
Macon NC-
448 PM EDT THU APR 27 2017

...A STRONG THUNDERSTORM WILL IMPACT NORTH CENTRAL RABUN...
SOUTHEASTERN MACON...SOUTHWESTERN TRANSYLVANIA AND SOUTHEASTERN
JACKSON COUNTIES UNTIL 530 PM EDT...

At 448 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles south of Franklin, or near Dillard, moving northeast at 50 mph.

Locations to be impacted include...
Highlands, Mountain City, Rosman, Dillard, Sky Valley, Cashiers, Lake
Toxaway, Lake Glenville, B.R. Parkway-Balsam Gap To Black Balsam Area
and Gorges State Park.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3538 8301 3533 8296 3532 8296 3531 8295
      3531 8294 3529 8292 3529 8291 3514 8279
      3490 8340 3505 8352
TIME...MOT...LOC 2048Z 236DEG 46KT 3503 8338

CDG

Special Weather Statement
National Weather Service Greenville-Spartanburg SC
457 PM EDT THU APR 27 2017

GAZ017-018-272145-
Stephens GA-Habersham GA-
457 PM EDT THU APR 27 2017

...A STRONG THUNDERSTORM WILL IMPACT WESTERN STEPHENS AND HABERSHAM
COUNTIES UNTIL 545 PM EDT...

At 457 PM EDT, Doppler radar was tracking a strong thunderstorm 5
miles south of Cleveland, or near Clermont, moving east at 45 mph.

Locations to be impacted include...
Toccoa, Clarkesville, Cornelia, Baldwin, Demorest, Mount Airy, Alto,
Tallulah Falls, Tallulah Gorge State Park and Raoul.

Wind gusts up to 45 mph and pea size hail will be possible in these
areas.

LAT...LON 3454 8362 3460 8365 3462 8364 3466 8366
      3473 8350 3473 8346 3475 8343 3473 8341
      3473 8338 3472 8335 3468 8334 3468 8332
      3447 8326 3446 8340 3448 8347 3449 8354
      3443 8362 3450 8367
TIME...MOT...LOC 2057Z 252DEG 31KT 3451 8377

CDG