An area of thunderstorms developing ahead of a cold front moved across northern portions of Upstate South Carolina during the morning, producing isolated wind damage. After a lull of a few hours, more numerous storms developed during the heat of the afternoon, producing more widespread severe weather, mainly in the form of large hail.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS GSP wrote it up.
An area of thunderstorms developing ahead of a cold front moved across northern portions of Upstate South Carolina during the morning, producing isolated wind damage. After a lull of a few hours, more numerous storms developed during the heat of the afternoon, producing more widespread severe weather, mainly in the form of large hail.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Greenville-Spartanburg, SC wrote its last area forecast discussion before the first event at Apr 20, 5:55 AM EST, 53 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
655 AM EDT MON APR 20 2015
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. DRY HIGH PRESSURE BUILDS IN FOR TUESDAY
AND WEDNESDAY. ANOTHER COLD FRONT WILL PUSH IN FROM THE NORTHWEST ON
THURSDAY...POSSIBLY BRINGING SHOWERS BACK TO THE AREA. A STRONGER
STORM SYSTEM WILL MOVE IN FOR THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM...WELL THE NEAR TERM MODELS AND CAMS ARE NOT DOING VERY
WELL WITH THE CONVECTION ENTERING OUR WESTERN ZONES EARLY THIS
MORNING. HAVE BUMPED UP POP IN THE WEST. STILL EXPECT WEAKENING AS
THE REMNANT PRECIP CROSSES THE AREA THRU THE MORNING HOURS. CANNOT
RULE OUT A STRONG OR MARGINALLY SEVERE STORM EARLY ON...BUT
OTHERWISE JUST SOME CG LIGHTNING AND DOWNPOURS WITH THAT ACTIVITY.
THE REST OF THE FCST WAS LEFT UNCHANGED.
AS OF 330 AM...IN THE IMMEDIATE NEAR TERM...THE RADAR HAS GONE INTO
CLEAR AIR MODE...AS A LEAD SHORTWAVE HAS EXITED TO THE NE WITHIN
DEEP LAYER SWLY FLOW. A QUASI-LINEAR MCS IS CURRENTLY CROSSING
CENTRAL TN AND NRN AL. GUIDANCE SEEMS TO BE UNDERESTIMATING THE
STRENGTH/PERSISTENCE OF THIS SYSTEM. THE LATEST RAP ANALYSIS SHOWS
500-1000 J/KG OF MUCAPE WITH 35-45 KTS OF EFFECTIVE SHEAR DOWNSTREAM
OF THIS CLUSTER. THIS RESULTS IN A /MCS MAINTENANCE/ PROB AT 70-80
PCT. SO IT IS NOW EXPECTED THAT THESE STORMS (WHILE STILL ON A
GRADUAL WEAKENING TREND) WILL LIKELY STILL SURVIVE INTO THE NC MTNS
EARLY THIS MORNING. GIVEN THE CURRENT STATE...CANNOT RULE OUT A
STRONG OR SEVERE STORM OR TWO...ESP IN GRAHAM/SWAIN...WHEN THE LINE
GETS INTO THE CWFA. FROM THERE...IT/S DIFFICULT TO SAY HOW MUCH
PRECIP WILL LINGER ACRS THE CWFA THIS MORNING. I HAVE BUMPED UP POP
IN THE WRN MTNS...BUT KEEP JUST A SHOTGUN CHC POP FOR THE REST OF
THE AREA THIS MORNING.
LATER TODAY...GUIDANCE IN GOOD AGREEMENT ON ANOTHER SPOKE OF
VORTICITY ROTATING AROUND THE BROAD CYCLONICALLY CURVED
FLOW...CROSSING THE CWFA FROM THE SOUTHWEST DURING THE PEAK-HEATING
AFTN HOURS. MEANWHILE...A COLD FRONT WILL PUSH INTO THE AREA THIS
AFTN. THE FRONT LOOKS TO ONLY HAVE MODEST LLVL CONVERGENCE.
HOWEVER...GIVEN THE STEEP MID LVL LAPSE RATES AND LINGERING BL
MOISTURE (DEWPTS IN THE MID 60S ACRS THE PIEDMONT). FAIRLY CONFIDENT
IN AT LEAST 40-50 PCT COVERAGE OF CONVECTION...MAYBE HIGHER TO THE
EAST. THE FCST SNDGS SHOW LONG BUT SLIGHTLY CURVED HODOGRAPHS WITH
1500-2500 J/KG OF UNCAPPED SBCAPE. SO EXPECT SOMEWHAT DISCRETE
STORMS INITIALLY...WITH POTENTIAL FOR SUPERCELLS. DEFINITELY WILL
BE A DAMAGING WIND AND HAIL THREAT...WITH AN ISOLD TORNADO THREAT
ACRS THE PIEDMONT THIS AFTN. THE HIGH RES MODELS DO NOT SEEM THAT
IMPRESSED WITH COVERAGE OR INTENSITY. I/M NOT SURE WHAT IS LIMITING
THEIR CONVECTION EXPECT FOR PERHAPS LACK OF DEEPER MOISTURE. THE NEW
DAY 1 CONVECTIVE OUTLOOK STILL HAS ALL AREAS EAST OF THE MTNS IN THE
SLGT RISK...AND A MARGINAL RISK FOR THE MTNS. OTHERWISE...IT WILL BE
BREEZY TODAY UNDER MOSTLY CLOUDY TO PARTLY CLOUDY SKIES WITH TEMPS
BACK ABOVE NORMAL AHEAD OF THE FRONT.
TONIGHT...DRY AIR WILL FILTER IN FROM THE WEST BEHIND THE FRONT.
POPS WILL TAPER OFF...LINGERING THRU THE EVENING ALONG THE TN BORDER
DUE TO UPSLOPE NWLY FLOW. LOWS WILL BE A COUPLE CATEGORIES ABOVE
NORMAL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 240 AM MONDAY...THINGS DRY OUT TUE AS DRY HIGH PRESSURE BUILDS
IN FROM THE WEST. EXPECT A MILD AND BREEZY DAY WITH HIGHS UP TO 5
DEGREES BELOW NORMAL. A BROAD AND LOW AMPLITUDE UPPER TROF SETS UP
ACROSS THE AREA FOR WED. WEAK SHORT WAVES MOVING THRU THE TROF WILL
HELP PUSH A WEAK COLD FRONT INTO THE AREA WED AND SOUTH OF THE AREA
WED NITE. THERE IS NOT A LOT OF DEEP MOISTURE WITH THIS SYSTEM AND
THE FORCING IS WEAK. THEREFORE...EXPECT SCT SHRA NEAR THE TN BORDER
WHERE THE MOISTURE IS DEEPEST AND WLY FLOW WILL HELP INCREASE
FORCING. ELSEWHERE...ONLY ISOLATED SHRA ARE EXPECTED...WITH LITTLE
CHC OF PRECIP SOUTH OF I-85. HIGHS WILL RISE TO NEAR NORMAL WED...
WITH LOWS NEAR NORMAL TUE NITE AND ABOVE NORMAL WED NITE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 350 AM MONDAY...AN UPPER TROF AXIS WILL SLIDE EAST OF THE AREA
THURSDAY ALLOWING FLAT RIDGING TO BUILD IN ON FRI. A SHORT WAVE
CROSSES THE AREA SATURDAY WITH ANOTHER BROAD AND LOW AMPLITUDE UPPER
TROF DEVELOPING ON SUNDAY.
HIGH PRESSURE BRIEFLY RETURNS TO THE AREA FRI BEFORE A STRONGER
STORM SYSTEM MOVES IN ON SATURDAY. PRECIP CHC SLOWLY RAMPS UP FRIDAY
WITH POTENTIALLY HEAVY PRECIP ON SATURDAY. DRY HIGH PRESSURE RETURNS
FOR SUNDAY. NEAR NORMAL HIGHS THURSDAY...FALL BELOW NORMAL FOR THE
REST OF THE PERIOD. LOWS BOUNCE AROUND FROM NEAR TO A LITTLE ABOVE
NORMAL.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT AND ELSEWHERE...PLENTY OF IFR TO MVFR LVL STRATUS ACRS THE
PIEDMONT THIS MORNING...SHUD LIFT AND SCATTER OUT TO A VFR LVL
CUMULUS DECK BY 14-16Z TIME FRAME. A BAND OF WEAKENING SHRA AND TSRA
ARE ENTERING WRN NC AT THE TIME OF THE TAF ISSUANCE. THE 06Z NAM
SEEMS TO HAVE THE BEST HANDLE ON THIS CONVECTION...CARRYING AN AREA
OF -RA ACRS THE NC MTNS AND FOOTHILLS...CLIPPING THE UPSTATE SITES
THIS MORNING. WILL MENTION SHRA AT KAVL AND VCTS AT KAND. NOT ENUF
CONFIDENCE ON ANY IMPACT AT GMU/GSP/HKY TO MENTION. BY MIDDAY...SW
WINDS WILL BECOME GUSTY ACRS THE ENTIRE AREA. A COLD FRONT WILL BE
PUSHING IN FROM THE WEST THIS AFTN...WITH GENERALLY ISOLD TO WIDELY
SCATTERED TSRA EXPECTED TO DEVELOP JUST OUT AHEAD OF THE FRONT ACRS
THE PIEDMONT. WILL CONTINUE TO MENTION PROB30 STARTING AT 21Z. WINDS
WILL SHIFT TO WNW EAST OF THE MTNS...AND NW AT KAVL BEHIND THE FRONT
THIS EVENING...GRADUALLY DIMINISHING OVERNIGHT.
OUTLOOK...DRY HIGH PRESSURE WILL BUILD IN ACROSS THE REGION FOR THE
MIDDLE OF THE WEEK...LEADING TO LOW PRECIP/RESTRICTION CHANCES.
CONFIDENCE TABLE...
11-17Z 17-23Z 23-05Z 05-06Z
KCLT MED 78% MED 69% HIGH 100% HIGH 100%
KGSP HIGH 85% MED 69% LOW 57% HIGH 100%
KAVL HIGH 93% HIGH 100% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 87% HIGH 100% HIGH 100%
KGMU HIGH 85% MED 69% HIGH 100% HIGH 100%
KAND HIGH 85% MED 75% 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: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
SYNOPSIS...RWH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...RWH
AVIATION...ARKHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 455 AM EDT MON APR 20 2015 GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065- 068>072-082-501>510-SCZ001>014-019-210900- 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- 455 AM EDT MON APR 20 2015 THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT NORTH CAROLINA...WESTERN NORTH CAROLINA AND UPSTATE SOUTH CAROLINA. .DAY ONE...TODAY AND TONIGHT. A COLD FRONT WILL CROSS THE AREA TODAY BRINGING ANOTHER ROUND OF SCATTERED THUNDERSTORMS. SOME OF THESE STORMS MAY BECOME SEVERE WITH DAMAGING WINDS AND LARGE HAIL. IN ADDITION...ISOLATED TORNADOES WILL BE POSSIBLE...MAINLY ACROSS THE PIEDMONT OF THE CAROLINAS AND NORTHEAST GEORGIA. WATER LEVELS WILL REMAIN HIGH IN AREA RIVERS AND STREAMS. ALTHOUGH THE STORMS WILL BE FAST MOVING...HEAVY RAINFALL IS POSSIBLE AND ISOLATED FLOODING MAY AGAIN DEVELOP. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY. ..TUESDAY...NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. ..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. .SPOTTER INFORMATION STATEMENT... NONE.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
709 AM EDT MON APR 20 2015
GAZ010-017-018-026-NCZ062>064-SCZ001-002-004-201200-
FRANKLIN GA-STEPHENS GA-RABUN GA-HABERSHAM GA-SOUTHERN JACKSON NC-
TRANSYLVANIA NC-MACON NC-PICKENS MOUNTAINS SC-GREATER OCONEE SC-
OCONEE MOUNTAINS SC-
709 AM EDT MON APR 20 2015
...A LINE OF STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF WESTERN
FRANKLIN...STEPHENS...RABUN...HABERSHAM...SOUTH CENTRAL SOUTHERN
JACKSON...SOUTHWESTERN TRANSYLVANIA...SOUTHEASTERN MACON...
NORTHWESTERN PICKENS MOUNTAINS...NORTHWESTERN GREATER OCONEE AND
OCONEE MOUNTAINS UNTIL 800 AM EDT...
AT 708 AM EDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 4 MILES SOUTH OF SKY VALLEY
TO CLARKESVILLE TO 4 MILES EAST OF GAINESVILLE...AND MOVING EAST AT
35 MPH.
PEA SIZE HAIL AND WIND GUSTS UP TO 40 MPH WILL BE POSSIBLE WITH THESE
STORMS.
LOCATIONS IMPACTED INCLUDE...
TOCCOA...WALHALLA...CLAYTON...CLARKESVILLE...CORNELIA...BALDWIN...
WESTMINSTER...DEMOREST...MOUNT AIRY AND ALTO.
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 THESE STORMS. 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. TRY TO UNPLUG UNNECESSARY APPLIANCES BEFORE THE
STORMS APPROACH.
&&
LAT...LON 3454 8362 3462 8364 3465 8366 3473 8362
3476 8363 3477 8365 3495 8355 3499 8353
3511 8272 3507 8277 3506 8276 3426 8334
3433 8339 3443 8338 3446 8340 3449 8354
3443 8362 3450 8367
TIME...MOT...LOC 1108Z 260DEG 31KT 3492 8331 3463 8352 3429 8376
RWHThe Greer radar (KGSP), 83 km away, was scanning. The volume nearest the first event began at 11:49 UTC.
24 hail, 4 thunderstorm wind. Local standard time, as filed.
EM reported mutliple trees blown down in the Westminster area, with one tree down on a home.
EM reported multiple trees and power lines blown down in the Forest Dr area.
Public reported hail up to the size of half dollars off Highway 290.
County comms reported quarter size hail south of Salem.
Public reported quarter size hail near Six Mile.
County comms reported quarter size hail in Travelers Rest.
Spotter reported nickel size hail near the Lake Robinson Dam.
County comms reported quarter size hail on Midway Rd (4.5 N Pickens). Spotter reported quarter size hail on Old Glassy Mountain Rd (3.5 NE). At least one other report of quarter size hail was received from this area.
HAM radio operator reported penny size hail.
CoCoRahs observer reported up to 2-inch diameter hail.
Spotters reported penny to quarter size hail in the Walhalla area.
Spotter reported quarter size hail.
Spotter reported dime to quarter size hail near the intersection of Island Creek Rd and Highway 110.
Spotter reported up to golf ball size hail near Taylors. Another spotter reported quarter size hail just north of Greer. At least one other quarter size hail report was received from the Greer area.
Public reported golf ball size hail near Liberty. Spotter reported penny size hail in Pickens.
Spotter reported 3/4 inch hail.
Public reported quarter size hail in Paris Mountain State Park.
Spotter reported multiple trees and power lines blown down in the Fair Play area.
Spotter reported quarter size hail.
Spotter reported quarter size hail on Hampton Rd (4 SW Inman) and Southfield St (1.5 SE).
NWS Storm Survey found intermittent wind damage, primarily confined to snapped limbs, small-to-medium sized uprooted trees, and a few large trees uprooted, was observed between Lake Hartwell and Highway 187, about 1 mile north of I-85. A couple of homes received minor roof damage in this area due to falling limbs or trees. Sporadic damage to trees continued east/northeast, across Highway 187, to Pine Needle Cir and Hix Dr, where the most significant damage was observed. A small house near the intersection of Hix Rd and Pine Needle Rd had much of the roof lifted and thrown, with debris spread into a field as far as 100 yards. Sporadic damage, mainly in the form of downed limbs, small snapped and uprooted hardwood trees, and larger uprooted softwoods continued northeast across Highway 71. Additional reports of sporadic damage were received from closer to Townville, including the Fair Play Rd area near the Oconee line.
Spotter reported quarter size hail.
Public reported quarter size hail via Social Media.
Public reported quarter size hail.
Multiple public reports of quarter size hail were received from the Union area.
Public reported a second severe thunderstorm produced another round of large hail in the Union area.
Public reported golf ball size hail.
Public reported quarter size hail at Highway 67 and Browntown Rd.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in South Carolina in 2015Every state in 2015This day in weather historyWarnings in South Carolina, April 2015
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 570118, 570119, 573529, 573537, 573541, 573530, 573531, 573542, 573532, 573533, 573538, 573539, 573545, 573534, 573543, 573535, 573536, 573605, 573540, 573546, 573612, 573547, 573548, 573553, 573571, 573578, 573581, 573583.