Alert archive / North Carolina / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 184, NWS Greenville-Spartanburg, SC

May 18, 2012Avery County, Mitchell County, North Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at May 18, 2012, 4:31 PM EDT for Avery County, Mitchell County, North Carolina. It was in force for 44 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 18, 2012, 4:31 PM EDT (20:31 UTC)
Expired: May 18, 2012, 5:15 PM EDT
In force: 44 min
Issued by: NWS Greenville-Spartanburg, SC
Area: Storm-based polygon

Counties Avery County, NC, Mitchell County, NC

The radar

The Knoxville radar (KMRX), 121 km from the middle of the area, began a volume at 20:32 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
May 18, 4:35 PM EDT	HAIL 0.5	5 Nnw Newland, NC	LOTS OF PEA SIZED HAIL FELL ALONG THE SOUTHERN PART OF ELK RIVER ROAD. PEA TO MARBLE SIZED HAIL FELL ON JOHN GREER ROAD NEARLY COVERING THE GROUND. GUSTY WIND OCCURRED BUT ONLY STRONG ENOUGH TO BLOW DOWN VERY SMALL LIMBS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 8.5 hours before the alert went out and 194 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 866 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: 12 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

524 
WUUS52 KGSP 182031
SVRGSP
NCC011-121-182115-
/O.NEW.KGSP.SV.W.0184.120518T2031Z-120518T2115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
431 PM EDT FRI MAY 18 2012

THE NATIONAL WEATHER SERVICE IN GREENVILLE-SPARTANBURG HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  AVERY COUNTY IN WESTERN NORTH CAROLINA...
  MITCHELL COUNTY IN WESTERN NORTH CAROLINA...

* UNTIL 515 PM EDT

* AT 430 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED NEAR
  NEWLAND...AND MOVING SOUTHWEST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL IMPACT LOCATIONS NEAR...
  NEWLAND.
  BAKERSVILLE AND INGALLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BRIEF DAMAGING WINDS WILL BLOW DOWN TREES AND POWER LINES OVER SMALL
AREAS. A BRIEF PERIOD OF LARGE HAIL IS ALSO POSSIBLE. SEEK SHELTER
INSIDE AN INTERIOR ROOM.

TO REPORT DAMAGING WINDS...HAIL...OR FLOODING THROUGH OUR AUTOMATED
REPORTING SYSTEM...CALL TOLL FREE...1 8 7 7...6 3 3...6 7 7 2.

&&

LAT...LON 3616 8181 3615 8182 3587 8206 3596 8219
      3602 8220 3600 8226 3603 8229 3614 8214
      3611 8212 3611 8208 3613 8205 3613 8204
      3625 8194
TIME...MOT...LOC 2032Z 040DEG 11KT 3614 8197

$$

ARK

1 follow-up statement

886 
WWUS52 KGSP 182106
SVSGSP

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
506 PM EDT FRI MAY 18 2012

NCC011-121-182116-
/O.EXP.KGSP.SV.W.0184.000000T0000Z-120518T2115Z/
AVERY NC-MITCHELL NC-
506 PM EDT FRI MAY 18 2012

...THE SEVERE THUNDERSTORM WARNING FOR MITCHELL AND AVERY COUNTIES
WILL EXPIRE AT 515 PM EDT...

THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LEVELS.  HOWEVER HEAVY RAIN IS STILL POSSIBLE WITH THIS THUNDERSTORM.

LAT...LON 3616 8181 3615 8182 3587 8206 3596 8219
      3602 8220 3600 8226 3603 8229 3614 8214
      3611 8212 3611 8208 3613 8205 3613 8204
      3625 8194
TIME...MOT...LOC 2106Z 040DEG 11KT 3606 8205

$$

ARK

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at May 18, 2:42 PM EDT, 1 hour 49 minutes earlier.

Area forecast discussion, May 18, 2:42 PM EDT, 1 hour 49 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
242 PM EDT FRI MAY 18 2012

.SYNOPSIS...
AN UPPER LEVEL LOW WILL PERSIST ALONG THE CAROLINA COAST THROUGH
EARLY NEXT WEEK. MEANWHILE...A RIDGE OF SURFACE HIGH PRESSURE WILL
REMAIN OVER THE REGION TONIGHT INTO NEXT EARLY WEEK. A COLD FRONT
WILL MOVE THROUGH THE REGION BY NEXT MID WEEK.

&&

.NEAR TERM /THROUGH SATURDAY/...
AT 230 PM...RADAR SHOWS SCATTERED SHOWERS/THUNDERSTORMS INCREASING
IN COVERAGE OVER THE MOUNTAINS AS EXPECTED. WE EXPECT SCATTERED TO
NUMEROUS SHOWERS/STORMS TO CONTINUE INTO THE EVENING HOURS. THE BEST
COVERAGE WILL BE OVER THE SW MOUNTAINS AND HAVE BUMPED POPS INTO
LIKELY COVERAGE RANGE THERE. SEVERE THREAT LOOKS LOOKS MINIMAL AS
WIND SHEAR LACKING...BUT THE STRONGER CORES COULD PRODUCE SUB-SEVERE
HAIL. ELSEWHERE...DRYER AIR IS BEGINNING TO FILTER INTO THE REGION
FROM THE NE. CLOUDINESS WILL BE BROKEN TO SCATTERED THROUGH THER
AFTERNOON WITH A CLEARING TREND FROM THE NE BY LATE AFTERNOON.

FOR THE OVERNIGHT...CONVECTION WILL GRADUALLY WANE OVER THE
MOUNTAINS WITH LOSS OF HEATING. HIGH PRESSURE OFF THE SOUTHERN NEW
ENGLAND COAST WILL RIDGE SW ACROSS THE AREA OVERNIGHT. THE RESULT
PER NUMERICAL MODEL GUIDANCE WILL BE MUCH DRYER AIR SPREADING ACROSS
MOST AREAS. DEWPOINTS ARE FORECAST TO LOWER INTO THE 40S OVER THE
EAST WITH MAINLY LOWER 50S WEST. ALSO...ANTICIPATE THAT CLOUDS WILL
CLEAR MOST AREAS...EXCEPT THE MOUNTAINS WHERE SOME UPSLOPE FLOW AND
LINGERING MOISTURE WILL CONTINUE. MIN TEMPS WILL RANGE FROM THE
UPPER 40S OVER THE NORTHERN MOUNTAINS TO THE UPPER 50S IN NE GA AND
SAVANNAH RIVER VALLEY

ON SAT...HIGH PRESSURE IS FORECAST TO CONTINUE TO RIDGE SW ALONG
THE EAST SLOPES OF THE APPALACHIANS WITH LOW RH. THIS WILL PRODUCE
MOSTLY CLEAR CONDITIONS WITH SEASONAL TEMPS. THE EXCEPTION WILL BE
THE SW MOUNTAINS...WHERE ENOUGH MOISTURE AND SLIGHTLY CONVERGENT
FLOW WILL SET OFF SOME WIDELY SCATTERED THUNDERSTORMS DURING THE
AFTERNOON.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AT 1430 EDT FRIDAY...AN UPPER LOW WILL BE LOCATED OFF THE SE NC
COAST ON SATURDAY NIGHT...SOUTHEAST OF AN UPPER RIDGE OVER IN. THIS
LOW REMAINS NEARLY STATIONARY THROUGH SUNDAY...WHILE THE UPPER RIDGE
MOVES TO NEW ENGLAND. BOTH THE GFS AND NAM MOVE THEIR LOWS NORTH ON
SUNDAY NIGHT...WITH THE NAM REACHING CENTRAL NC ON MONDAY...AND THE
GFS LOW REACHING THE CENTRAL COAST.

BOTH MODELS INITIALLY SHOW DRY AIR FROM THE NE ON SATURDAY EVENING.
THE NAM BRINGS MOISTURE WEST AROUND A COASTAL SURFACE LOW TO THE
INTERSTATE 77 CORRIDOR BY SUNDAY MORNING...WHILE THE GFS BRINGS
LESSER MOISTURE SOUTH ALONG THE BLUE RIDGE. THE NAM COASTAL LOW
MOISTURE REACHES THE BLUE RIDGE LATE SUNDAY...WHILE THE GFS HAS
MOISTURE ASSOCIATED WITH THE LOW JUST REACHING INTERSTATE 77...AND
SHOWS SEPARATE MOISTURE INCREASING OVER THE MOUNTAINS. EACH MODELS
MOISTURE PATTERN PERSISTS THROUGH SUNDAY NIGHT. ON MONDAY BOTH
MODELS MOVE THEIR COASTAL LOW MOISTURE EAST AND AWAY FROM THE
AREA...WHILE INCREASING MOISTURE FROM THE WEST INTO THE MOUNTAINS IN
ADVANCE OF AN APPROACHING...WEAKENING COLD FRONT.

WITH LIMITED CONFIDENCE ON THE ARRIVAL OF MOISTURE FROM THE NORTH OR
THE EAST...POPS WILL BE SMALL...ESPECIALLY IN GA AND SC. POPS WILL
INCREASE SLIGHTLY FROM THE WEST AS THE FRONT APPROACHES ON MONDAY.
TEMPERATURES START OFF A BIT BELOW NORMAL UNDER THE INFLUENCE OF THE
UPPER LOW...RISING TO NEAR OR SLIGHTLY ABOVE NORMAL WITH MINOR
HEIGHT RISES BETWEEN THE UPPER LOW AND AN APPROACHING MID LEVEL
SHORTWAVE CROSSING THE GREAT LAKES STATES ON MONDAY.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AT 230 PM FRIDAY...THE LATEST MODELS INDICATE THAT A LOW PRESSURE
ASSOCIATED WITH A COLD FRONT WILL MOVE THROUGH THE REGION BY
TUESDAY. THEN THE HPC AND GFS HINT THE FRONT PUSHING OFF THE
ATLANTIC COAST WED WHILE THE ECMWF KEEPS THE LOW JUST TO OUR EAST
THROUGH NEXT WEEKEND. MODEL BLEND WAS USED WITH POPS IN THE 40-50S
ON TUESDAY AND DROPPING TO 20S THROUGH OUT THE REST OF THE EXTENDED
FORECAST PERIOD. TEMPERATURES WILL REMAIN 3-5 DEGREES ABOVE NORMALS.

&&

.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...SAT IMAGES AND SURFACE OBS INDICATE SCT-BKN CU AT AND
AROUND THE AIRFIELD. EXPECT TEMPO CIGS AROUND 4KFT UNTIL LATE
AFTERNOON. DRYER AIR WILL CONTINUE TO FILTER IN FROM THE NE
OVERNIGHT WITH MAINLY SKC. WINDS WILL REMAIN OUT OF THE NE.

ELSEWHERE...GENERALLY SCT-BKN VFR CEILINGS AROUND 4KFT WITH SOME
BKN CLOUDS AROUND 10KFT AS WELL. EXPECT CLOUDS TO SCT BY LATE
AFTERNOON AS DRYER AIR FILTERS IN THE FROM THE NE. THE EXCEPTION
WILL BE AT KAVL WHERE VFR CEILINGS MAY PERSIST DUE TO SLIGHTLY
UPSLOPE FLOW. SOME MVFR FOG ALSO POSSIBLE LATE TONIGHT AT KAVL.

OUTLOOK...HIGH PRES WILL CONTROL THE WEATHER THROUGH SAT NIGHT WITH
DIURNAL TSTMS CONFINED TO MAINLY THE SW MOUNTAINS. MRNG FOG WILL BE
PSBL...ESPECIALLY IN THE MTN VALLEYS. VFR CLOUDS WILL INCREASE ON
SUN AS LOW PRESSURE TO THE EAST SPREADS MOISTURE OVER THE AREA. A
COLD FRONT WILL APPROACH FROM THE NW EARLY NEXT WEEK ALONG WITH AN
INCREASING CHANCE FOR AT LEAST SCATTERED SHOWERS/THUDNERSTORMS
THROUGHOUT THE AIR SPACE.

AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...

WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

SYNOPSIS...JOH
NEAR TERM...LG
SHORT TERM...JAT
LONG TERM...JOH
AVIATION...LG

Hazardous weather outlook, May 18, 3:11 AM EDT, 13 hours 20 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
311 AM EDT FRI MAY 18 2012

GAZ010-017-NCZ033-048>053-058-059-062>065-501-503-505-507-509-
SCZ001>003-190715-
RABUN-HABERSHAM-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-
311 AM EDT FRI MAY 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...WESTERN
NORTH CAROLINA AND UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

SCATTERED THUNDERSTORMS WILL DEVELOP THIS AFTERNOON ACROSS THE
SOUTHERN APPALACHIANS. COVERAGE OF THE THUNDERSTORMS WILL BE
HIGHEST ACROSS THE GREAT SMOKY MOUNTAINS AND LOCATIONS NEAR THE
TENNESSEE BORDER. THE MAIN HAZARDS WITH ANY THUNDERSTORMS THIS
AFTERNOON WILL BE CLOUD TO GROUND LIGHTNING STRIKES AND LOCALLY
HEAVY RAINFALL. HOWEVER...ONE OR TWO THUNDERSTORMS COULD PRODUCE
HAIL AS LARGE AS QUARTERS AND BRIEF BUT DAMAGING WIND GUSTS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ASKED TO RELAY ANY REPORTS OF HAIL...STRONG WINDS...OR
FLOODING TO THE NATIONAL WEATHER SERVICE.

GAZ018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-506-508-
510-SCZ004>014-019-190715-
STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-DAVIE-CATAWBA-ROWAN-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
GREATER CALDWELL-GREATER BURKE-EASTERN MCDOWELL-GREATER RUTHERFORD-
EASTERN POLK-GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-
SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-
CHESTER-GREENWOOD-
311 AM EDT FRI MAY 18 2012

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST GEORGIA...PIEDMONT
NORTH CAROLINA...WESTERN 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.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

NONE.

HG

In the hours before

Special weather statement, May 18, 3:18 PM EDT, 1 hour 13 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
318 PM EDT FRI MAY 18 2012

NCZ058-182000-
GRAHAM-
318 PM EDT FRI MAY 18 2012

...A STRONG THUNDERSTORM WILL AFFECT WESTERN GRAHAM COUNTY THROUGH
400 PM EDT...

AT 316 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR SANTEETLAH LAKE...OR 4 MILES WEST OF
ROBBINSVILLE...MOVING SOUTHWEST AT 5 MPH.

DIME SIZE HAIL...AND WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THIS
STORM.

LAT...LON 3537 8401 3539 8401 3545 8384 3529 8374
      3524 8381 3525 8384 3521 8396 3523 8401
      3531 8404 3536 8404

ARK

The office that day

Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 17, 8:12 PM EDT	Special Weather Statement	GSP	Jackson	48 min
May 17, 8:41 PM EDT	Special Weather Statement	GSP	Jackson	49 min
May 17, 9:12 PM EDT	Special Weather Statement	GSP	Davie	48 min
May 18, 1:31 AM EDT	Areal Flood Advisory	GSP	Burke	119 min
May 18, 3:18 PM EDT	Special Weather Statement	GSP	Graham	42 min
May 18, 5:27 PM EDT	Special Weather Statement	GSP	Buncombe	48 min
May 18, 6:17 PM EDT	Special Weather Statement	GSP	Haywood	43 min

Nearby

Severe Thunderstorm Warnings in North Carolina, 2012 Every severe thunderstorm warning in 2012

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.