Scattered thunderstorms developed across the mountains and foothills of western North Carolina throughout the afternoon. A few of the storms produced severe weather, mainly in the form of large hail, although a couple of areas of minor wind damage were reported.
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 thunderstorms developed across the mountains and foothills of western North Carolina throughout the afternoon. A few of the storms produced severe weather, mainly in the form of large hail, although a couple of areas of minor wind damage were reported.
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 May 19, 9:44 AM EST, 1 hour 36 minutes earlier.
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1044 AM EDT Fri May 19 2017
.SYNOPSIS...
Another summerlike day is expected today thanks to high pressure
near Bermuda. Saturday could be nearly identical as it looks more
like a cold front will stall to the north of our area. However, a
stronger system will move in from the west on Sunday and Sunday
night, bringing an excellent chance of rain. A cold front should
move east across the region on Monday. Unsettled weather will become
the rule for next week as several disturbances move through.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1035 am: upper ridge continues to stretch from the Gulf of
Mexico to the southwest Atlantic, with northwest flow aloft over the
Southern Appalachians. Deep upper low over the Rockies is
responsible for all the havoc in the Plains, but in itself will not
affect us till the short term. Weak front draped from the Southern
Plains surface low across the Ohio Valley and up the East Coast to a
low over Newfoundland. This boundary will provide focus for
convective development this afternoon and indeed SPC has continued
the Marginal Risk along it, but this stays to our north in VA. We'll
continue to be solidly in the warm sector today with southerly to
southwesterly low level flow. On top of that, a weak shortwave will
ride up the southwest flow and round the top of the ridge today,
providing a little extra oomph to the convective potential. Both the
GFS and the NAM have some portions of the Blue Ridge and Piedmont
with sbCAPEs rising to over 2000J/kg, but with a very tight CAPE
gradient to the southeast where modified airmass from the Bermuda
high will lead to lower dewpoints not supportive of convection.
These ingredients support a NW->SE gradient of afternoon pops
ranging from high chance/likely across the mtns, to less than slight
chance southeast of I-85.
Low level shear will remain weak, and this will tend to discourage
convective organization/clustering along cold pools. However, deep
layer shear is forecast to improve to around 30 kts later today, so
some weakly rotating cells could develop to enhance updraft
potential, thus supporting a threat of brief severe storms,
especially over the mountains.
Behind the shortwave passage tonight, the ridge will briefly pop
back up with a slightly higher amplitude, quickly helping to shut
off convection tonight except for maybe some isolated activity
lingering over the mountains. Temperatures continue 5-8 degrees
above seasonal normals for both highs and lows.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
As of 250 AM Friday: Been looking at this for the last five days
and still not entirely sure what to make of Saturday. The models
have been troubled with how to handle a back-door cold front,
which represents the edge of a cooler and drier air mass centered
over ern Canada. The trend in the guidance for the last 24-36 hrs
has been to hold the cold front to the N/NE of the fcst area, and
now the guidance barely has the boundary making down into the NW
Piedmont. Problem is, in many situations, the models do not handle
well how far to the S/SW these boundaries may ooze, particularly
when precip generated near the boundary helps to reinforce the
cooler air on the N side. The latest model guidance keeps almost
the entire fcst area dry through Saturday, but am not ready to
give up on our fcst that has a chance of precip mainly over NC,
because of the possibility that the boundary may ultimately make it
farther S before stalling/washing out. High temps will be highly
dependent on the boundary position. Have nudged the NW Piedmont
up a few degrees as a hedge against the boundary not making
it. Even if the boundary does, it should wash out Saturday night
and a developing S/SE low level flow should help to force precip
development in the upslope areas near the Blue Ridge Escarpment.
Another trend in the new model guidance is to bring more mid/upper
forcing in from the W/SW earlier on Sunday to act on deepening
Gulf moisture. The new ECMWF is in general agreement that more
widespread precip is likely to develop W to E across the fcst area
on Sunday, such that by the end of the day we have a gradient from
categorical over the wrn part to chance in the I-77 corridor. The
combination of 1000-1500 J/kg of CAPE and shear on the order of
20-25 kt suggests some threat of severe storms, but this is far
from certain. The best forcing will move east across the fcst
area during the overnight hours as a jet streak passes to the
north and the main short wave lifts out of the upper trof still to
our west. Precip prob has been raised into the categorical range
across the entire fcst area. Shear will maximize overnight just
high enough for concern, while CAPE remains fairly low.
Which brings us to Monday. Although the guidance has come into some
agreement with the timing of the passage of the cold front earlier
in the day, there is more indication that precip will linger on
the cooler side of the front longer into the day. As a result,
higher precip chances have been extended into the afternoon farther
to the west. Temps are a bit tricky again as we keep them close
to normal with lingering precip and cloud cover, but an earlier
departure might allow for more recovery if that happens.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
As of 330 AM Friday...any confidence in the passage of a cold
front to our east Monday night, allowing for some drying as weak
high pressure moves in, is quickly dashed by Tuesday as the
models continue to be at odds with how far south the boundary
will make it before stalling and how soon a wave will move along
the front. At least the guidance is consistent from run-to-run,
with the GFS still showing a fairly dry Tuesday while the ECMWF
brings the precip right back in from the SW with a wave during the
day. Will not attempt to reconcile that difference right now, as the
ongoing fcst has increasing precip chances during the day. However,
there is agreement that we will maintain deep moisture and some
forcing through Tuesday night and Wednesday as the next upper trof
swings across the TN valley and southeast. So, instead of showing
a brief lull in activity, it appears more likely that some chance
of precip will continue through the middle part of the week and
the fcst will be adjusted accordingly. The mid- to late-week part
of the fcst looks like it will be dominated by a long-wave upper
trof over the east, which should spell temps being held close to
normal. Few changes were made to the late part of the week.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
At KCLT and elsewhere: Midlevel deck moving across the area has
prevented much in the way of fog formation. Convection should
increase across the area late this morning and early afternoon,
beginning in the mountains and spreading into portions of the
Piedmont later in the day. KAVL and KHKY carry VCTS this afternoon,
and introduced VCSH at KCLT to account for low-end pops as well as
the HRRR occasionally progging convection to the NW of the airport.
Winds will be S to SW through the period, 5-10kt this afternoon and
diminishing again overnight. Increasing moisture should lead to an
increased chance of fog Saturday morning across the mountains, with
another slug of moisture moving into the Upstate but for now only
introduced MVFR at KAVL.
Outlook: Diurnal convection will increase again on Saturday ahead of
a backdoor cold front that approaches the forecast area from the
north over the weekend. Another front is expected to bring more
significant chances of showers/storms/restrictions early next week.
Confidence Table...
14-20Z 20-02Z 02-08Z 08-12Z
KCLT High 100% High 100% High 100% High 100%
KGSP High 100% High 100% High 100% High 100%
KAVL High 100% High 100% High 100% Med 79%
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 95%
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...PM
NEAR TERM...JDL/TDP
SHORT TERM...PM
LONG TERM...PM
AVIATION...TDPHazardous Weather Outlook National Weather Service Greenville-Spartanburg SC 631 AM EDT Fri May 19 2017 GAZ010-017-018-026-028-NCZ033-035>037-048>053-056>059-062>065- 068>072-501>510-SCZ001>008-010-201045- Rabun-Habersham-Stephens-Franklin-Hart-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-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-Anderson- 631 AM EDT Fri May 19 2017 This Hazardous Weather Outlook is for northeast Georgia, piedmont North Carolina, western North Carolina and upstate South Carolina. .DAY ONE...Today and Tonight. Scattered thunderstorms are expected to develop by this afternoon across the mountains and foothills of the Carolinas and northeast Georgia. Storms will be more isolated along the Interstate 85 corridor. The main threat from the storms will be frequent cloud-to- ground lightning, heavy downpours, gusty winds, and small hail. A few of the storms may become severe with large hail and damaging wind gusts. The storms should diminish in coverage and intensity this evening after sunset. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. ..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. ..Thursday...No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... None. GAZ029-NCZ082-SCZ009-011>014-019-201045- Elbert-Union-York-Abbeville-Laurens-Chester-Greenwood- 631 AM EDT Fri May 19 2017 This Hazardous Weather Outlook is for northeast Georgia, piedmont North Carolina and upstate South Carolina. .DAY ONE...Today and Tonight. No hazardous weather is expected at this time. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. ..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. ..Thursday...No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... None. PM
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
1146 AM EDT FRI MAY 19 2017
NCZ048-191615-
Madison NC-
1146 AM EDT FRI MAY 19 2017
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL MADISON COUNTY UNTIL
1215 PM EDT...
At 1145 AM EDT, Doppler radar was tracking a strong thunderstorm 5
miles northwest of Marshall, or 4 miles southeast of Hot Springs,
moving east at 15 mph.
Locations to be impacted include...
Marshall, Mars Hill, Hot Springs, Faust, Walnut, Spring Creek and
Luck.
Wind gusts up to 40 mph and pea size hail will be possible in these
areas.
LAT...LON 3597 8253 3580 8252 3574 8267 3573 8267
3574 8270 3573 8271 3572 8271 3574 8286
3592 8287 3593 8282 3592 8282 3593 8280
3596 8258 3595 8256
TIME...MOT...LOC 1545Z 268DEG 12KT 3583 8278
HGSpecial Weather Statement
National Weather Service Greenville-Spartanburg SC
1202 PM EDT FRI MAY 19 2017
NCZ048-053-191630-
Buncombe NC-Madison NC-
1202 PM EDT FRI MAY 19 2017
...A STRONG THUNDERSTORM WITH INTENSE LIGHTNING WILL IMPACT CENTRAL
MADISON AND NORTHERN BUNCOMBE COUNTIES UNTIL 1230 PM EDT...
At 1201 PM EDT, Doppler radar was tracking a strong thunderstorm with
intense lightning near Marshall, moving east at 25 mph.
Locations to be impacted include...
Marshall, Mars Hill, Weaverville, Faust, Walnut, Canto, Wolf Ridge
and Barnardsville.
In addition to intense lightning, wind gusts up to 40 mph and dime
size hail will be possible in these areas.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
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 3595 8248 3593 8250 3592 8249 3591 8249
3591 8248 3589 8245 3586 8242 3582 8241
3582 8236 3572 8234 3569 8280 3588 8280
3596 8250
TIME...MOT...LOC 1601Z 259DEG 21KT 3581 8270
HGThe Knoxville radar (KMRX), 77 km away, was scanning. The volume nearest the first event began at 16:20 UTC.
7 hail, 2 thunderstorm wind. Local standard time, as filed.
PD reported trees blown down along Baileys Branch Road just south of the river.
Spotter reported quarter size hail on Heritage Circle.
Multiple public reports of large hail were received (via Social Media) from the Blowing Rock area.
Public reported two trees blown down near Dana.
Public reported dime to quarter size hail at the corner of Old Fort Sugar Hill Rd and Sugar Hill Rd.
Spotter reported 3/4 inch hail.
Public reported quarter size hail off Pinnacle Mountain Rd.
Public reported nickel size hail along Pinnacle Falls Ln.
Public reported quarter size hail.
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, May 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: 702585, 702567, 702584, 702586, 702579, 702583, 702576, 702569, 702570.