Alert archive / South Carolina / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 20, NWS Greenville-Spartanburg, SC

May 21, 2001Greenville County, South Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at May 21, 2001, 9:34 PM EDT for Greenville County, South Carolina. It was in force for 26 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 21, 2001, 9:34 PM EDT (01:34 UTC)
Expired: May 21, 2001, 10:00 PM EDT
In force: 26 min
Issued by: NWS Greenville-Spartanburg, SC
Area: Whole counties

County Greenville County, SC

What was reported inside it

Time	Report	Where	Remark
May 21, 9:45 PM EDT	Thunderstorm Wind 50 E	Tigerville, SC	Storm survey found area of downed trees 2 miles west of the highway 11/14 interchange.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 1.6 hours before the alert went out and 259 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: 634 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 1322 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 104 m²/s²
0-3 km storm-relative helicity: 122 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

000 
WUUS52 KGSP 220134
SVRGSP
SCC045-220200-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
934 PM EDT MON MAY 21 2001

THE NATIONAL WEATHER SERVICE IN GREENVILLE-SPARTANBURG HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHERN GREENVILLE COUNTY IN UPSTATE SOUTH CAROLINA

* UNTIL 1000 PM EDT

* AT 934 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
  THUNDERSTORM WITH LARGE HAIL 14 MILES SOUTHWEST OF COLUMBUS...OR
  ABOUT 3 MILES NORTH OF TIGERVILLE...MOVING EAST AT 25 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GOWENSVILLE AT 950 PM EDT

ALTHOUGH LARGE HAIL IS THE BIGGEST THREAT WITH THIS SEVERE
THUNDERSTORM...BRIEF DAMAGING WINDS COULD ALSO OCCUR.

$$

RWH

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 21, 2:38 PM EDT, 6 hours 56 minutes earlier.

Area forecast discussion, May 21, 2:38 PM EDT, 6 hours 56 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
238 PM EDT MON MAY 21 2001

SIGNIFICANT SHORTWAVE REACHES AREA THIS EVENING IN RUC...CROSSING
AREA TONIGHT. THIS FEATURE ACCOMPANIED BY UPPER DIVERGENCE...OMEGA
AND LOW LEVEL CONVERGENCE. CAPES REMAIN HIGH THROUGH THE EVENING...
MID LEVELS TO BE SOMEWHAT DRY. DIRECTIONAL SHEAR DECREASES HOWEVER.
EXPECT ACTIVITY TO PEAK AROUND 06Z...WITH MOUNTAINS MOST FAVORED.
MODELS DIFFER ON FROPA...BUT GENERALLY CLUSTER AROUND AN AFTERNOON
FROPA AT GSP AND EARLY EVENING AT CLT. OMEGA/UL DIVERGENCE/LL
CONVERGENCE PEAK AGAIN NEAR FROPA...WHEN COLUMN MOIST SFC-400 MB.

DRYING FROM W BEGINS TUE AFTERNOON IN MOUNTAINS. DOWNSLOPE DOES NOT
LAST LONG ENOUGH TO SAVE LEE OF MOUNTAINS FROM COLD ADVECTION WED.
MOISTURE ASSOCIATED WITH LARGE UPPER LOW REACHES TN LINE THU. MEDIUM
RANGE MODELS DIFFER REGARDING SURFACE LOW AND ITS MOISTURE...AS WELL
AS ANY COASTAL DEVLOPMENT ON A SECONDARY FRONT DOWNSTREAM. STUCK
WITH THE MAIN FACTS FOR EXTENDED: LARGE CLOSED LOW AND MOISTURE TO
NW...WITH SOME AMOUNT OF UPSLOPE COMPONENT ON TN LINE. WITH THAT IN
MIND...KEPT CLOUDS/SHOWERS/COLD NC MOUNTAINS THU-SUN...WITH PARTLY
CLOUDY AND COOL E OF MOUNTAINS...MODERATING TOWARD WEEKEND. ONE
EXCEPTION WAS FRI WHEN MODELS BRING SECONDARY FRONT ACROSS FROM
W...WHICH HAS CONSISTENCY FROM YESTERDAYS RUNS. CARRYING POPS ALL
LOCATIONS FRI.

FCSTID = 7
GSP   67  77  52  75 /  60  70  20  10
AND   68  78  53  76 /  60  70  20  10
CLT   66  76  51  74 /  60  70  30  10
HKY   65  75  50  72 /  60  70  10  10
AVL   63  71  46  68 /  70  70  10  20

.GSP...
GA...NONE.
NC...NONE.
SC...NONE.

In the hours before

Local storm report, May 21, 3:40 PM EDT, 5 hours 54 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREENVILLE SPARTANBURG SC
340 PM EDT MON MAY 21 2001

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LO,CATION....

250 PM     10 E COLUMBUS             NC   FLASH FLOOD
05/21/01   POLK                           SHERIFF REPORTED FLOODING
                                          IN GREEN CREEK AREA.

JAT

The office that day

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

Issued	Product	Office	Counties	Lasted
May 22, 2:33 PM EDT	Severe Thunderstorm Warning	GSP	Greenville, Spartanburg	42 min
May 22, 4:26 PM EDT	Severe Thunderstorm Warning	GSP	York	34 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive.