Alert archive / South Carolina / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 13, NWS Greenville-Spartanburg, SC
NWS Greenville-Spartanburg, SC issued this severe thunderstorm warning at Apr 24, 1999, 3:24 PM EDT for Greenville County, Laurens County, South Carolina. It was in force for 46 min. 3 reports 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
- Apr 24, 1999, 3:24 PM EDT (19:24 UTC)
- Expired
- Apr 24, 1999, 4:10 PM EDT
- In force
- 46 min
- Issued by
- NWS Greenville-Spartanburg, SC
- Area
- Whole counties
Counties Greenville County, SC, Laurens County, SC
The radar
The Greer radar (KGSP), 22 km from the middle of the area, began a volume at 19:27 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 |
|---|---|---|---|
| Apr 24, 3:28 PM EDT | Hail 0.88 | Fountain Inn, SC | |
| Apr 24, 3:44 PM EDT | Hail 0.75 | Gray Court, SC | |
| Apr 24, 4:06 PM EDT | Hail 1.75 | Laurens, 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, 7.4 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.
- Mixed-layer CAPE
- 1372 J/kg
- Mixed-layer CIN
- -118 J/kg
- Mixed-layer LCL
- 784 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 125 m²/s²
- 0-3 km storm-relative helicity
- 137 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
999 WUUS1 KGSP 241925 RRA SVRGSP SCC045-059-242010- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 324 PM EDT SAT APR 24 1999 THE NATIONAL WEATHER SERVICE IN GREENVILLE-SPARTANBURG HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... SOUTHEASTERN GREENVILLE COUNTY IN SOUTH CAROLINA NORTHERN LAURENS COUNTY IN SOUTH CAROLINA * UNTIL 410 PM EDT * AT 322 PM EDT... NATIONAL WEATHER SERVICE RADAR INDICATED A SEVERE THUNDERSTORM 17 MILES NORTHWEST OF LAURENS OR 5 MILES NORTHWEST OF OWINGS... MOVING SOUTHEAST AT 25 MPH. * THE SEVERE THUNDERSTORM WILL BE NEAR... OWINGS AT 330 PM EDT GRAY COURT AT 335 PM EDT LANFORD AT 345 PM EDT ORA AT 350 PM EDT LAURENS AT 355 PM EDT ALTHOUGH LARGE HAIL IS THE BIGGEST THREAT WITH THIS SEVERE THUNDERSTORM...BRIEF DAMAGING WINDS COULD ALSO OCCUR. DEO
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 24, 2:55 PM EDT, 29 minutes earlier.
Area forecast discussion, Apr 24, 2:55 PM EDT, 29 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC 255 PM EDT SAT APR 24 1999 ISOLATED TSTMS FIRING ATTM IN GSP VCNTY IN HIGHER DWPT/CNVRG AXIS... AS PER LATEST ADAP & MESOANALYSIS. WILL BASE DECISION ON WHETHER TO INCLUDE EVENING PERIOD IN ZFP FOR THIS ACTIVITY OR JUST NOWCAST BASED ON COVERAGE AT ISSUANCE TIME...ABOUT 330-345 PM. OTHERWISE...WILL CONTINUE 30% POP FOR LIGHT RAIN WHERE CURRENTLY MENTIONED TONIGHT DUE TO COMBINATION OF DEVELOPING WEAK SOUTHERLY 850 MB FLOW...UPSLOPE AND CONVERGENCE ALONG INVERTED SFC TROUGH. NEW SHORT RANGE GUIDANCE IN DECENT AGREEMENT IN KEEPING FORCING MINIMAL IN WEAK NW FLOW ALOFT THEREAFTER THROUGH SUNDAY NIGHT WITH AVAILABLE RH NARROW & CONFINED TO AROUND 850 MB. BY 48 HRS...12Z MON...UPPER LEVEL FEATURES HANDLED SIMILARLY BY MODELS WITH S/WV RIDGE AXIS STILL WEST OF MTNS WITH AVN TRANSLATING THIS FEATURE EASTWARD DURING THE DAY IN RESPONSE TO UPPER LOW HEADING ACROSS THE PLAINS. EFFECTS OF LLVL RIDGING EXPECTED TO BE LESSENING SO LIKELY TO SEE INCREASING AMTS OF DEEPER RH & RETURN FLOW. FWC/FAN NUMBERS IN AGREEMENT WITH CHC POPS FOR WESTERN SECTIONS IN THE AFTERNOON & AT THIS POINT LOOKS TO BE REASONABLE & WILL FOLLOW. AVL 49/65/49/71 3213 CLT 50/70/52/76 2112 GSP 55/71/53/77 3213 .GSP...NONE. CSH
The office that day
Everything else NWS Greenville-Spartanburg, SC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 3:50 PM EDT | Tornado Warning | GSP | Laurens | 30 min |
| Apr 24, 4:19 PM EDT | Tornado Warning | GSP | Laurens | 51 min |
Nearby
Severe Thunderstorm Warnings in South Carolina, 1999Every severe thunderstorm warning in 1999
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.