A couple of broken lines of thunderstorms moved across western North Carolina during the afternoon and early evening. A few of the storms produced brief severe weather, mainly in the form of damaging wind gusts.
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.
A couple of broken lines of thunderstorms moved across western North Carolina during the afternoon and early evening. A few of the storms produced brief severe weather, mainly in the form of damaging wind gusts.
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 Aug 12, 2:01 PM EST, 46 minutes earlier.
Area Forecast Discussion National Weather Service Greenville-Spartanburg SC 301 PM EDT Sat Aug 12 2023 .SYNOPSIS... A round of thunderstorms, some strong to severe, will move in from the west this afternoon and evening. Thunderstorm chances return Sunday and Monday afternoons, along with hotter and more humid weather. Monday's heat could be dangerous in the Piedmont for some individuals. A cold front Monday night and Tuesday will restore milder and drier weather for mid-week. && .NEAR TERM /THROUGH SUNDAY/... As of 230 PM EDT Saturday: Convection developing across the Cumberland Plateau appears to be taking over as the leading edge of a loosely organized MCS. This activity is forming in an environment with over 2500 J/kg of MLCAPE, and 25-30 kt of effective shear with up to 1000 J/kg of DCAPE. So the expectation now is that tstms will probably be strong to severe as they enter the NC mountains later this aftn. A Severe Tstm Watch 635 has been issued for the NC mountains, the adjacent foothills and most of the Upstate and NE GA until 00z (8 pm EDT). How much this activity will survive further east is still a big question mark. The 17z HRRR now has the strongest storms push SE into NE GA and the Upstate, possibly still strong. The NC Piedmont seems the least likely to see storms, given the lowest CAPE and some capping from NWLY downslope 850 mb flow, but slight chc PoPs will be retained there. The main threat will be damaging wind gusts, but isolated hail up to 1"-diameter will also be possible. Convection should wane this evening, as an upper-level shortwave exits to our east. Mountain valley fog is expected, with patchy fog possible elsewhere. Lows will be slightly above normal, mainly in the upper 60s in the mountain valleys to mid 70s in the lower Piedmont. A slight building of heights from the large subtropical ridge should help suppress convection somewhat Sunday. Low-level flow will be weak, and generally backing to WSWLY, resulting in less downslope. Guidance is showing less mixing of the dewpts during the aftn, and with highs getting into the mid 90s, we could see plenty of 105-109 heat indices across the Upper Savannah Valley and just south and east of Charlotte. Given that just a deg or two difference in the temp or dewpt could keep us below advisory criteria, we will hold off on an advisory with this forecast package and let the midnight shift assess the latest guidance. Otherwise, expect isolated to widely scattered convection across the Piedmont and scattered storms across the mountains, with a couple of pulse severe storms possible. && .SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/... As of 245 PM Saturday: Monday is looking very similar to Sunday. We're left with convective scraps that die off Sunday evening while a lead short wave moves past to the north. The upper pattern remains flat into Monday with somewhat uncertain evolution of an MCS over the Cumberland Plateau and central Appalachians. However, consensus is that we should be in a warm sector of sorts with more than adequate instability to support thunderstorms developing by afternoon. The fcst has precip probs close to climo. The storm chances look good over the mtns, but a cap east of the mtns on fcst soundings supports limiting to a slight risk. The big problem for Monday will be the temps and heat index. Altho high temps might only be on the order of five degrees above normal...well short of records...the dewpoint climbs a bit more into the middle 70s which suggests a good bet for at least a Heat Advisory for a large part of the area east of the mtns. Some places might reach Warning criteria along/S of I-85. Only concern is how such a plan could go awry with convective debris or early storm development keeping us from getting warm enough. That leads us into Tuesday, when model guidance suggests a cold frontal boundary will be dropping down across the forecast area during peak heating. The guidance affords us an excellent opportunity to develop an environment with sufficient buoyancy and shear to support organized severe storms along/S of the front Tuesday afternoon/eve east of the mtns. Temps drop off a few degrees which may take care of the heat advisory concern at least. && .LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/... As of 227 PM Saturday: The cold front is expected to push E/SE of the fcst area by sunset on Tuesday, or shortly thereafter, as a shortwave moves east and past to our north. High pressure will build in from the northwest behind the front for the middle part of the week, with drier and cooler air bringing some relief. The model trend is toward temps being a few degrees below normal for the rest of the work week as the high slides past. What is uncertain is how quickly our usual diurnal convection returns, because of big differences in how the guidance handles the evolution of a mid/upper trof late in the week. The ECMWF and Canadian keep a relatively deep trof axis off to our west through the end of the period that keeps a west/northwest flow into the region thru Friday that would be inhospitable to deep convection. The GFS is more muddled and shows a weak upper low cutting off to our west that would bring moisture back by Friday. The ECMWF/Canadian look preferable at this point, but the forecast will end up with an unmentionable slight risk for late week because of the model blend. Expect changes as agreement improves. && .AVIATION /19Z SATURDAY THROUGH THURSDAY/... At KCLT and elsewhere: Low confidence forecast with an approaching cluster of thunderstorms crossing central TN at time of 18z TAF issuance. The last few runs of the HRRR have consistently brought some of that convection across the mountains and into the Piedmont this evening. However, confidence of it reaching CLT, as anything more than a few dying showers is still too low to mention in a TEMPO. However, amendments will be made if trends change. KAVL and the Upstate sites have slightly better chances of TS, so will mention with VCTS for now. Debris cloudiness should slowly thin overnight, leaving mostly clear skies with light winds. The mountain valleys stand a good chance to fog up again overnight, while patchy fog will be possible across the Piedmont. Not expecting as much fog as this morning. Outlook: Daily shower and thunderstorm chances with associated restrictions will continue the rest of the weekend and thru the first half of next week. Mountain valley fog/low stratus will be possible each morning. Drier conditions expected to return Wednesday. && .GSP WATCHES/WARNINGS/ADVISORIES... GA...None. NC...None. SC...None. && SYNOPSIS...PM NEAR TERM...ARK SHORT TERM...PM LONG TERM...PM AVIATION...ARK
Hazardous Weather Outlook National Weather Service Greenville-Spartanburg SC 257 PM EDT Sat Aug 12 2023 GAZ010-NCZ033-048>053-058-059-062>065-501-503-505-507-509-SCZ101>103- 131900- Rabun-Avery-Madison-Yancey-Mitchell-Swain-Haywood-Buncombe-Graham- Northern Jackson-Macon-Southern Jackson-Transylvania-Henderson- Caldwell Mountains-Burke Mountains-McDowell Mountains- Rutherford Mountains-Polk Mountains-Oconee Mountains- Pickens Mountains-Greenville Mountains- 257 PM EDT Sat Aug 12 2023 ...SEVERE THUNDERSTORM WATCH 635 IN EFFECT UNTIL 8 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. Scattered to numerous thunderstorms are expected to move in from the west late this afternoon or early this evening. Some of the thunderstorms will have the potential to produce severe weather in the form of damaging wind gusts of up to 60 mph and hail. Any of the storms may produce cloud-to-ground lightning, gusty winds, and torrential downpours. The storms should weaken or move east of the mountains by late evening. .DAYS TWO THROUGH SEVEN...Sunday through Friday. No hazardous weather is expected at this time. .SPOTTER INFORMATION STATEMENT... None. GAZ029-NCZ035>037-056-057-068>072-082-SCZ008-009-011>014-019-131900- Elbert-Alexander-Iredell-Davie-Catawba-Rowan-Cleveland-Lincoln- Gaston-Mecklenburg-Cabarrus-Union NC-Cherokee-York-Abbeville-Laurens- Union SC-Chester-Greenwood- 257 PM EDT Sat Aug 12 2023 This Hazardous Weather Outlook is for northeast Georgia, piedmont North Carolina and upstate South Carolina. .DAY ONE...This afternoon and tonight. Scattered thunderstorms today may produce cloud-to-ground lightning and gusty winds. A stray storm or two could produce minor wind damage, mainly this evening. Also, heat index may rise into the upper 90s or lower 100s this afternoon, mainly over northeast Georgia, Upstate South Carolina, and the Charlotte metro area. This could pose a risk of heat-related illness in some people. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Heat index Sunday afternoon is likely to rise into the lower 100s in many locations, possibly above 105 in some spots. Still hotter and more humid weather is expected Monday afternoon, when heat index may rise above 110. These conditions being more likely to cause heat illnesses, a Heat Advisory or even an Excessive Heat Warning could be issued Sunday and/or Monday. .SPOTTER INFORMATION STATEMENT... None. GAZ017-018-026-028-NCZ502-504-506-508-510-SCZ010-104>109-131900- Habersham-Stephens-Franklin-Hart-Greater Caldwell-Greater Burke- Eastern McDowell-Greater Rutherford-Eastern Polk-Anderson- Greater Oconee-Greater Pickens-Central Greenville- Southern Greenville-Northern Spartanburg-Southern Spartanburg- 257 PM EDT Sat Aug 12 2023 ...SEVERE THUNDERSTORM WATCH 635 IN EFFECT UNTIL 8 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. Scattered thunderstorms today may produce cloud-to-ground lightning and gusty winds. A stray storm or two could produce minor wind damage, mainly this evening. Also, heat index may rise into the upper 90s or lower 100s this afternoon, mainly over northeast Georgia, Upstate South Carolina, and the Charlotte metro area. This could pose a risk of heat-related illness in some people. .DAYS TWO THROUGH SEVEN...Sunday through Friday. Heat index Sunday afternoon is likely to rise into the lower 100s in many locations, possibly above 105 in some spots. Still hotter and more humid weather is expected Monday afternoon, when heat index may rise above 110. These conditions being more likely to cause heat illnesses, a Heat Advisory or even an Excessive Heat Warning could be issued Sunday and/or Monday. .SPOTTER INFORMATION STATEMENT... None.
Special Weather Statement
National Weather Service Greenville-Spartanburg SC
323 PM EDT Sat Aug 12 2023
NCZ051-059-122015-
Swain NC-Northern Jackson NC-
323 PM EDT Sat Aug 12 2023
...A strong thunderstorm will impact portions of north central
Jackson and northeastern Swain Counties through 415 PM EDT...
At 323 PM EDT, Doppler radar was tracking a strong thunderstorm 11
miles northeast of Bryson City, or near Smoky Mountains-Oconaluftee,
moving east at 15 mph.
HAZARD...Wind gusts up to 50 mph and half inch hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor damage to outdoor objects is
possible.
Locations impacted include...
Smoky Mountains-Oconaluftee, Smoky Mountains-Balsam Mountain,
Cherokee, B.R. Parkway-Smoky Mountains To Balsam Gap, Smoky
Mountains-Newfound Gap and Smoky Mountains-Deep Creek.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Severe Thunderstorm Watch remains in effect until 800 PM EDT for
western North Carolina.
&&
LAT...LON 3561 8339 3559 8318 3558 8317 3556 8316
3554 8317 3553 8317 3551 8318 3550 8318
3545 8320 3552 8341
TIME...MOT...LOC 1923Z 282DEG 12KT 3554 8330
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH
TWThe Knoxville radar (KMRX), 78 km away, was scanning. The volume nearest the first event began at 19:43 UTC.
15 thunderstorm wind, 2 hail. Local standard time, as filed.
County comms reported a couple of trees blown down near the Blue Ridge Parkway and Highway 19. A couple of trees were also down closer to Maggie Valley and in Waynesville.
County comms reported numerous trees blown down across Graham County. Public reported multiple large trees down in Robbinsville and vicinity alone.
County comms reported numerous trees blown down across Swain County. Some were down across power lines.
County comms reported several trees blown down in northern Haywood County.
Public reported several trees blown down in the Cashiers area.
Public reported half inch to three-quarter inch hail along Lower Mountain Creek Rd.
County comms reported numerous trees blown down across Madison County.
Public reported golf ball size hail.
County comms reported power lines blown down on a tree down on Nantahala Shores, a tree down on Camp Branch Rd, and another tree down on Wayah Rd.
Utility company reported trees blown down on power lines.
County comms reported trees blown down on Possum Trot Rd, on Little Creek Rd, on Highway 197, and Bakers Creek Rd.
Utility company reported multiple trees blown down on power lines in the Saluda area.
Utility company reported trees blown down on power lines in the Bakersville area.
Utility company reported several trees blown down on power lines in the Tryon area and another tree down on power lines near Columbus.
County comms reported multiple trees blown down in the Lawndale area.
County comms reported multiple trees blown down in the Waco area.
County comms reported multiple trees blown down in the Kings Mountain area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Carolina in 2023Every state in 2023This day in weather historyWarnings in North Carolina, August 2023
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: 1136889, 1136890, 1136891, 1136892, 1136897, 1136904, 1136893, 1136905, 1136896, 1136898, 1136894, 1136899, 1136895, 1136900, 1136901, 1136902, 1136903.