Alert archive / South Carolina / Severe Thunderstorm Warnings in 2006

Severe Thunderstorm Warning 93, NWS Greenville-Spartanburg, SC

April 21, 2006Greenwood County, South Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Apr 21, 2006, 8:52 PM EDT for Greenwood County, South Carolina. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Apr 21, 2006, 8:52 PM EDT (00:52 UTC)
Expired: Apr 21, 2006, 9:30 PM EDT
In force: 38 min
Issued by: NWS Greenville-Spartanburg, SC
Area: Counties, with a storm outline in the text

County Greenwood County, SC

The radar

The Greer radar (KGSP), 82 km from the middle of the area, began a volume at 00:55 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.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 0.9 hours before the alert went out and 236 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: 347 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1609 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: 62 m²/s²
0-3 km storm-relative helicity: 75 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

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 Apr 21, 3:03 PM EDT, 5 hours 49 minutes earlier.

Area forecast discussion, Apr 21, 3:03 PM EDT, 5 hours 49 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
303 PM EDT FRI APR 21 2006

.SHORT TERM /TONIGHT THROUGH MONDAY/...
AREA OF ORGANIZED CONVECTION ASSOCIATED WITH LOW LEVEL CONVERGENCE
AT THE NOSE OF THE LLJ AND W/IN UPPER DIVERGENCE SOUTH OF THE UPPER
JET IS LIFTING INTO THE CENTRAL APPALACHIANS/OHIO VALLEY AS
EXPECTED. STILL EXPECT TERRAIN INFLUENCES...GENERAL WEAK ISENTROPIC
UPGLIDE...AND LOW LEVEL CONVERGENCE ALONG SURFACE TROUGH ACROSS
GEORGIA TO ALLOW FOR ISOLATED (EAST) TO NUMEROUS (WEST) SHOWERS/
STORMS TO DEVELOP THROUGH THE AFTERNOON AND EARLY EVENING.
HOWEVER...THE MAIN SHOW WILL BE LATER THIS EVENING THROUGH THE
PRE-DAWN HOURS...AS SURFACE BOUNDARY APPROACHES FROM THE TENN
VALLEY. WEAK SURFACE LOW PRESSURE DEVELOPING ALONG THIS FEATURE
ACROSS THE LOWER MISS VALLEY WILL MAXIMIZE CONVERGENCE ACROSS THE
TENN VALLEY THIS EVENING...THEN ACROSS THE NC MNTNS DURING THE
PRE-DAWN HOURS. IN FACT...THE NAM AND GFS DEPICT AN EXTENDED PERIOD
OF STRONG LOW/LEVEL CONVERGENCE/UPPER LEVEL DIVERGENCE (DEEP/STRONG
OMEGA) ACROSS THE WESTERN MOUNTAINS LATE TONIGHT. CONSIDERING PWATS
ARE 150-175 PERCENT OF NORMAL...AM CONSIDERED ABOUT THE POTENTIAL
FOR EXCESSIVE RAINFALL...AS WE EXPECT QPF IN THE 2-3 INCH RANGE
ALONG THE TENNESSEE BORDER. IF WE WERE NOT IN THE MIDDLE OF A
DROUGHT...I WOULD PROBABLY PULL THE TRIGGER...BUT CONSIDERING
ANTECEDENT CONDITIONS...WILL ALLOW THE EVENING SHIFT TO FURTHER
EVALUATE THE POTENTIAL.

FURTHER SOUTH AND EAST...IT APPEARS THE POTENTIAL FOR AN ORGANIZED
MCS TO DEVELOP ACROSS MS/AL/GA THIS AFTERNOON AND EVENING THEN MOVE
INTO OUR SOUTHWEST ZONES IS QUITE HIGH (BASED ON REGIONAL RADAR
TRENDS)...AND WILL FEATURE CATEGORICAL POPS FROM I-26 WEST ACROSS
THE UPSTATE/NE GEORGIA. AS THE FRONT MOVES ACROSS THE AREA
SATURDAY...POPS WILL DIMINISH FROM WEST TO EAST ACROSS THE CWFA.
-JDL

EXPECT ALL THE FORCING TO BE EAST OF THE FORECAST AREA BY 00Z
SUNDAY...SO THE PRECIP CHANCE WILL BE CUT WAY BACK SATURDAY EVENING
WEST OF I-77. WILL RETAIN A LOW CHANCE I-77 AND EAST JUST IN CASE
THE TIMING IS OFF...BUT EXPECT THE PRECIP TO BE LONG GONE BY THEN.

FROM SATURDAY NIGHT ONWARD...THE WESTERN CAROLINAS SHOULD REMAIN
UNDER A NW FLOW ALOFT WITH A SUCCESSION OF WEAK WAVES ROUNDING THE
CLOSED LOW AND DROPPING DOWN ACROSS THE REGION. THIS PATTERN IS
UNFAVORABLE TO ANY PRECIP EAST OF THE MOUNTAINS SO THE PIEDMONT WILL
BE KEPT DRY THROUGH MONDAY. OVER THE MOUNTAINS THOUGH...EXPECT
ENOUGH INSTABILITY TO SUPPORT THE DEVELOPMENT OF WIDELY SCATTERED
DIURNAL SHOWERS AND THUNDERSTORMS SUNDAY AND MONDAY. THERE IS THE
DISTINCT POSSIBILITY THAT UPSTREAM MCS FORMATION COULD IMPACT THE
MOUNTAINS...PARTICULARLY SUNDAY EVENING...BUT FOR NOW WILL KEEP POP
IN THE SLIGHT CHANCE RANGE. FAVORED THE WARMER MET GUIDANCE FOR MIN
TEMPS WITH THE POSSIBILITY OF MORE CLOUDS. -PM

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE MEDIUM RANGE PERIOD SHOULD START OUT WITH A NEARLY ZONAL
FLOW...WHICH WILL TRANSITION TO A BROAD TROFFINESS OVER THE
CAROLINAS FOR LATE TUESDAY AND INTO THURSDAY. SHORT WAVES MOVING
ALONG IN THE FLOW WILL HELP TO BRING A SLOW MOVING COLD FRONT ACROSS
THE REGION...PROBABLY TUESDAY NIGHT OR EARLY WEDNESDAY. GIVEN THIS
SCENARIO...THE ONGOING FORECAST FOR THIS TIME PERIOD STILL LOOKS
REASONABLE...AND THE POP WILL ACTUALLY BE BUMPED UP TO LIKELY ALONG
THE TN BORDER FOR TUESDAY. THE INCREASED CLOUD COVER SUPPORTS A
WARMER MIN TEMP TUESDAY MORNING...SO THIS WAS NUDGED UP AS MUCH AS A
CATEGORY IN SOME SPOTS. ACTUALLY...MIN TEMPS WERE RAISED A FEW
DEGREES EACH NIGHT BASED ON THE GUIDANCE TREND...GIVEN AN UPPER TROF
THAT IS NOT AS DEEP. THE PRECIP CHANCE WILL BE KEPT TUESDAY NIGHT
AND WEDNESDAY...AND WILL BE BACKED OFF WEDNESDAY NIGHT AS THE FRONT
SINKS WELL SOUTH OF THE FORECAST AREA. THURSDAY AND FRIDAY LOOK DRY
AS HIGH PRESSURE BUILDS IN FROM THE WEST WITH WEAK UPPER RIDGING
UPSTREAM.

&&

.AVIATION...
MAIN CONCERN FOR THIS PERIOD IS WITH CHANCES FOR CONVECTION
AFFECTING THE TERMINALS THIS EVENING AND OVERNIGHT. EXPECT THE
CHANCES FOR ORGANIZED CONVECTION TO BE QUITE LOW ACROSS THE REGION
THIS AFTERNOON AND EARLY THIS EVENING. THERE WILL CERTAINLY BE
SCATTERED (PIEDMONT) TO NUMEROUS (MNTNS) SHOWERS AND STORMS
ABOUT... BUT DETERMINING WHEN/WHERE THESE MAY AFFECT ONE OF THE
TERMINALS IS NEXT TO IMPOSSIBLE AT THIS POINT. ORGANIZED
CONVECTION WILL BE MORE LIKELY TONIGHT...AS FRONTAL BOUNDARY
APPROACHES THE AREA. WE HAVE INTRODUCED CATEGORICAL CONVECTION TO
THE TERMINALS GENERALLY AFTER MIDNIGHT ACROSS THE WEST...AND
CLOSER TO SUNRISE ACROSS THE EAST. MVFR CIGS AND AT LEAST MVFR FOG
WILL LIKELY ACCOMPANY BURSTS OF CONVECTIVE PRECIP. DEEP CONVECTIVE
CHANCES WILL CONTINUE INTO THE EARLY AFTERNOON HOURS
TOMORROW...ESPECIALLY ACROSS THE PIEDMONT.

&&

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

SHORT TERM...JDL/PM
LONG TERM...MOORE
AVIATION...JDL

Hazardous weather outlook, Apr 21, 3:31 AM EDT, 17 hours 21 minutes before

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
331 AM EDT FRI APR 21 2006

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-
SCZ001>014-019-220745-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-CALDWELL-
ALEXANDER-IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-
BUNCOMBE-MCDOWELL-BURKE-CATAWBA-ROWAN-GRAHAM-NORTHERN JACKSON-
MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-POLK-RUTHERFORD-
CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-UNION NC-
OCONEE MOUNTAINS-PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-
GREATER OCONEE-GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-
CHEROKEE-YORK-ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-
GREENWOOD-
331 AM EDT FRI APR 21 2006

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

.DAY ONE...TODAY AND TONIGHT

LOOK FOR THUNDERSTORMS IN THE AREA TODAY AND TONIGHT. SOME STORMS
COULD BECOME SEVERE...THE MAIN THREAT BEING LARGE HAIL AND WIND.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THUNDERSTORMS ARE EXPECTED TO CONTINUE ACROSS THE AREA SATURDAY INTO
SATURDAY EVENING. THERE IS ANOTHER CHANCE OF THUNDERSTORMS
WEDNESDAY AND WEDNESDAY NIGHT. SOME STORMS COULD BE SEVERE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATER TODAY.

In the hours before

Local storm report, Apr 21, 8:15 PM EDT, 37 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
815 PM EDT FRI APR 21 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0810 PM     HAIL             1 N GREER               34.95N 82.23W
04/21/2006  E0.75 INCH       GREENVILLE         SC   AMATEUR RADIO

&&

PTANNER

Local storm report, Apr 21, 8:31 PM EDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
831 PM EDT FRI APR 21 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0830 PM     HAIL             HONEA PATH              34.45N 82.39W
04/21/2006  E1.00 INCH       ANDERSON           SC   LAW ENFORCEMENT

&&

PTANNER

Local storm report, Apr 21, 8:40 PM EDT, 12 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
840 PM EDT FRI APR 21 2006

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0815 PM     HAIL             GREENVILLE              34.86N 82.40W
04/21/2006  E0.88 INCH       GREENVILLE         SC   PUBLIC

&&

HG

Local storm report, Apr 21, 8:41 PM EDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
841 PM EDT FRI APR 21 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0834 PM     HAIL             2 SE PRINCETON          34.48N 82.26W
04/21/2006  E0.88 INCH       LAURENS            SC   LAW ENFORCEMENT

            DEPUTY ALONG HIGHWAY 25.

&&

CSH

Local storm report, Apr 21, 8:46 PM EDT, 6 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
846 PM EDT FRI APR 21 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0840 PM     HAIL             LYMAN                   34.95N 82.12W
04/21/2006  E0.75 INCH       SPARTANBURG        SC   AIRPLANE PILOT

&&

CSH

Local storm report, Apr 21, 8:52 PM EDT, 0 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
852 PM EDT FRI APR 21 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0852 PM     HAIL             10 N CLINTON            34.62N 81.87W
04/21/2006  E1.00 INCH       SPARTANBURG        SC   NWS EMPLOYEE

&&

PTANNER

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 22, 1:48 AM EDT	Severe Thunderstorm Warning	GSP	Transylvania	51 min
Apr 22, 2:27 AM EDT	Severe Thunderstorm Warning	GSP	Henderson	63 min
Apr 22, 4:22 AM EDT	Severe Thunderstorm Warning	GSP	Gaston, Lincoln	53 min
Apr 22, 5:05 AM EDT	Severe Thunderstorm Warning	GSP	Davie, Iredell, Rowan	55 min
Apr 22, 5:12 AM EDT	Severe Thunderstorm Warning	GSP	Mecklenburg	63 min
Apr 22, 6:07 AM EDT	Severe Thunderstorm Warning	GSP	Union	38 min
Apr 22, 2:46 PM EDT	Severe Thunderstorm Warning	GSP	Rowan	52 min
Apr 22, 4:20 PM EDT	Severe Thunderstorm Warning	GSP	Union	24 min
Apr 22, 4:58 PM EDT	Severe Thunderstorm Warning	GSP	Cabarrus	45 min
Apr 22, 5:21 PM EDT	Severe Thunderstorm Warning	GSP	Rowan	31 min
Apr 22, 5:34 PM EDT	Severe Thunderstorm Warning	GSP	Mecklenburg	56 min
Apr 21, 8:05 PM EDT	Severe Thunderstorm Warning	GSP	Greenwood	40 min
Apr 21, 8:05 PM EDT	Severe Thunderstorm Warning	GSP	Laurens	55 min
Apr 21, 8:34 PM EDT	Severe Thunderstorm Warning	GSP	Spartanburg	56 min
Apr 21, 9:02 PM EDT	Tornado Warning	GSP	Spartanburg	14 min
Apr 21, 9:09 PM EDT	Severe Thunderstorm Warning	GSP	Greenville	44 min
Apr 21, 9:29 PM EDT	Severe Thunderstorm Warning	GSP	Spartanburg	49 min
Apr 21, 10:56 PM EDT	Severe Thunderstorm Warning	GSP	Chester	64 min
Apr 22, 1:03 AM EDT	Severe Thunderstorm Warning	GSP	Oconee	57 min
Apr 22, 2:08 AM EDT	Severe Thunderstorm Warning	GSP	Greenville	67 min
Apr 22, 3:21 AM EDT	Severe Thunderstorm Warning	GSP	Abbeville	29 min
Apr 22, 12:50 AM EDT	Severe Thunderstorm Warning	GSP	Habersham	28 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2006 Every severe thunderstorm warning in 2006

Sources

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