Alert archive / South Carolina / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 18, NWS Columbia, SC
NWS Columbia, SC issued this severe thunderstorm warning at Apr 15, 1999, 5:39 PM EDT for Aiken County, South Carolina. It was in force for 36 min. 2 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 15, 1999, 5:39 PM EDT (21:39 UTC)
- Expired
- Apr 15, 1999, 6:15 PM EDT
- In force
- 36 min
- Issued by
- NWS Columbia, SC
- Area
- Whole counties
County Aiken County, SC
The radar
The Columbia radar (KCAE), 66 km from the middle of the area, began a volume at 21:43 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 15, 5:48 PM EDT | Thunderstorm Wind 50 | Jackson, SC | Police reported several large tree branches down. |
| Apr 15, 5:50 PM EDT | Hail 0.75 | Jackson, SC | Police reported dime size hail. |
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 watch it was issued in
The SPC watch in force over the same counties when this warning went out.
| Issued | Product | Office | Lasted |
|---|---|---|---|
| Apr 15, 4:15 PM EDT | Tornado Watch | SPC | 6 hr |
The nearest sounding before it
Charleston AFB, SC (KCHS), launched 12:00Z, 9.7 hours before the alert went out and 168 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
- 148 J/kg
- Mixed-layer CIN
- -103 J/kg
- Mixed-layer LCL
- 695 m above ground
- 0-6 km bulk shear
- 70 kt
- 0-1 km storm-relative helicity
- 286 m²/s²
- 0-3 km storm-relative helicity
- 347 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.6
The text
As transmitted, in the capitals the NWS used until 2016.
999 WUUS1 KCAE 152140 RRA SVRCAE SCC003-152215- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE COLUMBIA SC 539 PM EDT THU APR 15 1999 THE NATIONAL WEATHER SERVICE IN COLUMBIA SC HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... AIKEN COUNTY IN SOUTH CAROLINA * UNTIL 615 PM EDT * AT 538 DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM JUST WEST OF NEW ELLENTON. THE STORM WAS MOVING EAST AT 45 MPH. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE TORNADOES WITH LITTLE OR NO ADVANCE WARNING. REMAIN CALM BUT BE ALERT TO RAPIDLY CHANGING WEATHER CONDITIONS. THIS IS A DANGEROUS STORM...TAKE COVER IMMEDIATELY IF YOU ARE IN ITS PATH. INTENSE SEVERE THUNDERSTORMS CAN CAUSE AS MUCH DAMAGE AS SOME TORNADOES. LM
The office that day
Everything else NWS Columbia, SC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 15, 4:13 PM EDT | Tornado Warning | CAE | Bamberg | 32 min |
| Apr 15, 4:38 PM EDT | Severe Thunderstorm Warning | CAE | Newberry | 52 min |
| Apr 15, 5:52 PM EDT | Tornado Warning | CAE | Aiken, Barnwell | 38 min |
| Apr 15, 6:26 PM EDT | Tornado Warning | CAE | Bamberg | 34 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.