Scattered evening thunderstorms developed in association with a surface trough and an unseasonably warm and moist air mass across western North Carolina. Although some wind damage was reported across the mountains in association with weakening storms moving into the area from East Tennessee, the bulk if activity was across the southern Piedmont, where multiple supercell thunderstorms produced…
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.
Scattered evening thunderstorms developed in association with a surface trough and an unseasonably warm and moist air mass across western North Carolina. Although some wind damage was reported across the mountains in association with weakening storms moving into the area from East Tennessee, the bulk if activity was across the southern Piedmont, where multiple supercell thunderstorms produced large hail, with stones up to the size of baseballs causing damage to vehicles and structures in the Harrisburg area.
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 Mar 21, 6:32 PM EST, 29 minutes earlier.
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...SBKHazardous 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.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
651 PM EDT TUE MAR 21 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0525 PM HAIL 6 NE GREENVILLE 34.89N 82.29W
03/21/2017 E2.00 INCH GREENVILLE SC NWS EMPLOYEE
2 INCH HAIL ON OVERCUP CT IN GREER FROM 525-550PM. DAMAGE
TO SIDING.
&&
LVISINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
705 PM EDT TUE MAR 21 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0702 PM HAIL 3 SSE GREER 34.90N 82.22W
03/21/2017 E1.75 INCH SPARTANBURG SC NWS EMPLOYEE
GOLF BALL SIZE HAIL AT THE NWS GSP OFFICE AT THE GSP
AIRPORT...AGAIN
&&
LVISINPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
726 PM EDT TUE MAR 21 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0725 PM HAIL CARNESVILLE 34.37N 83.23W
03/21/2017 E0.50 INCH FRANKLIN GA PUBLIC
DIME SIZE HAIL IN CARNESVILLE
&&
LVISINSpecial Weather Statement
National Weather Service Greenville-Spartanburg SC
733 PM EDT TUE MAR 21 2017
SCZ003-006-007-220000-
Greenville Mountains SC-Spartanburg SC-Greater Greenville SC-
733 PM EDT TUE MAR 21 2017
...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN GREENVILLE AND
NORTHWESTERN SPARTANBURG COUNTIES UNTIL 800 PM EDT...
At 733 PM EDT, Doppler radar was tracking a strong thunderstorm 10
miles southwest of Columbus, or 5 miles northeast of Tigerville,
moving east at 20 mph.
Locations to be impacted include...
Landrum, Slater-Marietta, Inman, Campobello, Lake Bowen, Tigerville,
Lake Robinson, Pleasant Ridge State Park, Jones Gap State Park and
Greer.
Wind gusts up to 40 mph and half inch hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
A severe thunderstorm watch remains in effect until 1100 PM EDT for
Upstate South Carolina.
LAT...LON 3511 8262 3517 8247 3517 8244 3518 8243
3520 8238 3519 8238 3518 8237 3519 8235
3519 8232 3520 8229 3519 8202 3498 8212
3492 8231
TIME...MOT...LOC 2333Z 285DEG 16KT 3512 8229
MOORESpecial Weather Statement
National Weather Service Greenville-Spartanburg SC
738 PM EDT TUE MAR 21 2017
NCZ070-071-220015-
Gaston NC-Mecklenburg NC-
738 PM EDT TUE MAR 21 2017
...A STRONG THUNDERSTORM WILL IMPACT NORTHWESTERN MECKLENBURG AND
NORTHEASTERN GASTON COUNTIES UNTIL 815 PM EDT...
At 738 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles southwest of Huntersville, or near Paw Creek, moving east at 20
mph.
Locations to be impacted include...
Uptown Charlotte, Huntersville, Central Charlotte, Northeast
Charlotte, Northwest Charlotte, Mt Holly, Belmont, Stanley, Lowell
and Ranlo.
Wind gusts up to 40 mph and dime size hail will be possible in these
areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3517 8081 3521 8102 3528 8115 3538 8119
3541 8108 3540 8096 3542 8095 3539 8075
TIME...MOT...LOC 2338Z 285DEG 16KT 3532 8093
MOORESpecial Weather Statement
National Weather Service Greenville-Spartanburg SC
744 PM EDT TUE MAR 21 2017
NCZ068>070-220015-
Gaston NC-Cleveland NC-Lincoln NC-
744 PM EDT TUE MAR 21 2017
...A STRONG THUNDERSTORM WILL IMPACT LINCOLN...CENTRAL CLEVELAND AND
NORTHWESTERN GASTON COUNTIES UNTIL 815 PM EDT...
At 744 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles west of Lincolnton, or 5 miles north of Cherryville, moving
east at 20 mph.
Locations to be impacted include...
Gastonia, Lincolnton, Cherryville, Bessemer City, Dallas, Belwood,
High Shoals, Lawndale, Fallston and Waco.
Dime size hail will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
This storm may intensify, so be certain to monitor local radio and tv
stations, as well as local cable tv outlets for additional
information and possible warnings from the National Weather Service.
&&
LAT...LON 3553 8107 3523 8117 3538 8164 3553 8164
3557 8151
TIME...MOT...LOC 2344Z 285DEG 16KT 3547 8139
MOOREThe Greer radar (KGSP), 138 km away, was scanning. The volume nearest the first event began at 00:02 UTC.
7 hail, 2 thunderstorm wind. Local standard time, as filed.
Multiple sources reported quarter to golf ball size hail from north Charlotte to the UNCC area.
Public reported quarter size hail in the Cornelius and Davidson areas.
Public reported golf ball to tennis ball size hail near Harrisburg.
County comms reported numerous trees blown down.
Public reported ping pong ball to baseball size hail covering the ground on Moss Creek Drive.
Public measured 1.5 inch diameter hail near Denver. At least one other report of large hail was received from the Denver area.
Public reported quarter size hail near Rockwell.
Spotter reported quarter size hail.
County comms reported a few trees blown down on power lines from the Balsam Grove area to Brevard.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Carolina in 2017Every state in 2017This day in weather historyWarnings in North Carolina, March 2017
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 2026-09-24. Each event’s entry at NCEI: 686267, 686268, 686284, 686266, 686286, 686282, 686291, 686292, 686294.