Alert archive / South Carolina / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 229, NWS Greenville-Spartanburg, SC

July 21, 2002Pickens County, South Carolina

NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Jul 21, 2002, 5:30 PM EDT for Pickens County, South Carolina. It was in force for 60 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
Jul 21, 2002, 5:30 PM EDT (21:30 UTC)
Expired
Jul 21, 2002, 6:30 PM EDT
In force
60 min
Issued by
NWS Greenville-Spartanburg, SC
Area
Whole counties

County Pickens County, SC

The radar

The Greer radar (KGSP), 46 km from the middle of the area, began a volume at 21:30 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

TimeReportWhereRemark
Jul 21, 6:38 PM EDTHail 0.75Dacusville, SC

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 12:00Z, 9.5 hours before the alert went out and 235 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-pSkew-T log-p diagram, Peachtre/Fal Fld, GA at 12:00Z on 2002-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1664 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Peachtre/Fal Fld, GA at 12:00Z on 2002-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 4 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1664 J/kg
Mixed-layer CIN
-48 J/kg
Mixed-layer LCL
935 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
4 m²/s²
0-3 km storm-relative helicity
7 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.

059 
WUUS52 KGSP 212130
SVRGSP
SCC077-212230-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
530 PM EDT SUN JUL 21 2002

THE NATIONAL WEATHER SERVICE IN GREENVILLE-SPARTANBURG HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EASTERN PICKENS COUNTY IN UPSTATE SOUTH CAROLINA

* UNTIL 630 PM EDT

* AT 530 PM EDT...NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE
  THUNDERSTORM WITH DAMAGING WINDS 9 MILES NORTHWEST OF GREENVILLE...
  OR ABOUT 4 MILES SOUTHEAST OF DACUSVILLE...MOVING SOUTHWEST AT 10
  MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  EASLEY AT 600 PM EDT.
  PICKENS AT 620 PM EDT.
  LIBERTY AT 630 PM EDT.

PEOPLE IN THE PATH OF THIS SEVERE THUNDERSTORM SHOULD BE ALERT FOR
LARGE HAIL AND DAMAGING WINDS. FREQUENT LIGHTNING AND LOCALLY HEAVY
RAIN CAN OCCUR WITH ANY THUNDERSTORM.

$$

NED

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 Jul 21, 3:20 PM EDT, 2 hours 10 minutes earlier.

Area forecast discussion, Jul 21, 3:20 PM EDT, 2 hours 10 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
320 PM EDT SUN JUL 21 2002

KGSP 88D LOOPS INDICATE ISOLATED TSTMS FIRING ACRS THE UPSTATE
& INTO THE MTNS...AIDED BY ENE LLVL FLOW. LAPS DATA INDICATES
GREATER INSTABILITY THAN WHAT WE HAVE SEEN THE PAST SVRL DAYS
WITH VALUES RANGING FROM AROUND 1500 J/KG IN THE MTNS TO NEAR
2500 J/KG IN THE PIEDMONT. VWP INDICATES A UNIFORMLY DEEP BUT
WEAK ENE FLOW ALL THE WAY UP THRU THE COLUMN. GIVEN THIS
PROFILE...SOME MARGINAL ISOLATED SVR NOT OUT OF THE QUESTION
& STORMS MAY BE ENHANCED ALONG THE ESCARPMENT...WITH LOCALIZED
HEAVY RNFL...BUT OVERALL CVRG SHOULD REMAIN 20% OR LESS THRU
MID-EVENING.

ON MONDAY...RETROGRADING WEAK UPPER LVL LOW IS PROGGED TO BE
LOCATED OVER THE CWFA & SHORT RANGE MODELS ARE ALL INDICATING
A FAIR AMOUNT OF LARGE SCALE UVV...ESPECIALLY OVER THE MTNS.
WOULD EXPECT MORE...MAINLY DIURNALLY FIRED TSTM CVRG THAN
WHAT WE ARE SEEING ATTM...BUT WILL NOT DRIFT FROM GOING CHC POPS.

PATTERN LOOKS TO BE MORE ACTIVE THRU THE MIDWEEK PERIOD AS
UPPER TROUGH PERSISTS ACRS THE ERN U.S. & PERIODIC VORTS ROTATE
IN FROM THE NORTHWEST. SYNOPTIC SCALE SFC BNDRY IS ALSO PROGGED
TO APPROACH AND LINGER NEAR THE CWFA THIS PERIOD ALONG WITH
DEEPER RH. ALL THIS SHOULD ADD UP TO HIGHER THAN CLIMO POPS
TUE-THU.

FOR DAYS 5-7...UPPER PATTERN WILL DEAMPLIFY AND EASTERN U.S
TROUGH TO BE REPLACED WITH A MORE ZONAL FLOW...ALTHOUGH
EXPECTEDLY WEAK FLOW OVER THE SE US. DEEP RH LOOKS TO GET
DISPLACED AS WELL...SO A RETURN TO MORE TYPICAL DIURNALLY
FIRED...SCATTERED...IF THAT...DEEP CONVECTION.

FCSTID = 55
GSP   72  90  71  90 /  10  30  30  40
AND   72  91  71  91 /  10  30  30  40
CLT   71  91  70  90 /   0  30  30  40
HKY   69  89  69  89 /   0  30  30  40
AVL   65  86  66  85 /  10  40  30  40

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

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 7:41 PM EDTSevere Thunderstorm WarningGSPOconee64 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2002Every severe thunderstorm warning in 2002

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; radar from the NEXRAD Level II archive.