Alert archive / South Carolina / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 52, NWS Charleston, SC

April 21, 2012Berkeley County, South Carolina

NWS Charleston, SC issued this severe thunderstorm warning at Apr 21, 2012, 2:51 PM EDT for Berkeley County, South Carolina. It was in force for 24 min. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Apr 21, 2012, 2:51 PM EDT (18:51 UTC)
Expired
Apr 21, 2012, 3:15 PM EDT
In force
24 min
Issued by
NWS Charleston, SC
Area
Storm-based polygon

County Berkeley County, SC

The radar

The Columbia radar (KCAE), 110 km from the middle of the area, began a volume at 18:54 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
Apr 21, 2:57 PM EDTHAIL 1Eadytown, SC
Apr 21, 3:11 PM EDTTSTM WND GST 5014 Wnw Saint Stephen, SCTHUNDERSTORM WIND GUST WAS MEASURED AT THE NWS HANDAR SITE ON SANTEE DAM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 6.9 hours before the alert went out and 59 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, Charleston AFB, SC at 12:00Z on 2012-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 754 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Charleston AFB, SC at 12:00Z on 2012-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 square meters per square second.19395878Sfc1 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
754 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
750 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
124 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.6

Open this sounding in Storm Lab

The text

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

674 
WUUS52 KCHS 211851
SVRCHS
SCC015-211915-
/O.NEW.KCHS.SV.W.0052.120421T1851Z-120421T1915Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE CHARLESTON SC
251 PM EDT SAT APR 21 2012

THE NATIONAL WEATHER SERVICE IN CHARLESTON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN BERKELEY COUNTY IN SOUTHEAST SOUTH CAROLINA...

* UNTIL 315 PM EDT

* AT 252 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM...NEAR EADYTOWN...MOVING NORTHEAST AT 10 MPH.

  PREPARE NOW FOR THE FOLLOWING HAZARDS...
  DAMAGING WINDS IN EXCESS OF 60 MPH...
  HAIL UP TO QUARTER SIZE...
  TORRENTIAL RAIN WHICH MAY PRODUCE LOCALIZED FLOODING...

* SOME LOCATIONS IN THE WARNING INCLUDE...
  EADYTOWN...CROSS...EASTERN LAKE MARION...SAINT STEPHEN...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REPORT HAIL...DOWNED TREES...LIMBS...AND POWER LINES DIRECTLY TO THE
CHARLESTON NATIONAL WEATHER SERVICE AT 1-888-383-2024.

&&

LAT...LON 3350 7996 3344 7988 3326 7997 3328 8027
      3336 8024 3339 8025 3340 8023 3344 8023
      3346 8015 3348 8016 3350 8013 3351 8008
TIME...MOT...LOC 1852Z 204DEG 10KT 3342 8016

$$
2 follow-up statements
211 
WWUS52 KCHS 211906
SVSCHS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
306 PM EDT SAT APR 21 2012

SCC015-211915-
/O.CON.KCHS.SV.W.0052.000000T0000Z-120421T1915Z/
BERKELEY SC-
306 PM EDT SAT APR 21 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 315 PM EDT
FOR NORTHWESTERN BERKELEY COUNTY...

AT 307 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM NEAR WILSONS LANDING...MOVING
NORTHEAST AT 10 MPH.

PREPARE NOW FOR THE FOLLOWING HAZARDS...
DAMAGING WINDS IN EXCESS OF 60 MPH...
HAIL UP TO QUARTER SIZE...

SOME LOCATIONS IN OR NEAR THE PATH OF THIS STORM INCLUDE...BONNEAU...
BONNEAU BEACH...CROSS...EADYTOWN...EASTERN LAKE MARION...NORTHERN
LAKE MOULTRIE...SAINT STEPHEN AND SOUTHERN LAKE MOULTRIE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPORT SEVERE WEATHER SUCH AS HAIL...DOWNED TREES...LIMBS...AND
POWER LINES...PLEASE CONTACT THE CHARLESTON NATIONAL WEATHER SERVICE
TOLL FREE AT 1-888-383-2024 OR EMAIL YOUR REPORTS TO
CHS.SKYWARN@NOAA.GOV.

&&

LAT...LON 3350 7996 3344 7988 3326 7997 3328 8027
      3336 8024 3339 8025 3340 8023 3344 8023
      3346 8015 3348 8016 3350 8013 3351 8008
TIME...MOT...LOC 1907Z 204DEG 10KT 3346 8014

$$
798 
WWUS52 KCHS 211916
SVSCHS

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
316 PM EDT SAT APR 21 2012

SCC015-211926-
/O.EXP.KCHS.SV.W.0052.000000T0000Z-120421T1915Z/
BERKELEY SC-
316 PM EDT SAT APR 21 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN BERKELEY COUNTY
WILL EXPIRE AT 315 PM EDT...

AT 316 PM EDT...RADAR INDICATED THAT THE THUNDERSTORMS WHICH PROMPTED
THE WARNING HAD WEAKENED...THUS THE SEVERE THUNDERSTORM WARNING HAS
BEEN ALLOWED TO EXPIRE.

ALTHOUGH THE SEVERE THUNDERSTORM WARNING IS NO LONGER IN 
EFFECT...THUNDERSTORMS ARE STILL CAPABLE OF PRODUCING GUSTY 
WINDS...NICKEL SIZE HAIL...FREQUENT LIGHTNING AND HEAVY RAINFALL. 
THE SAFEST COURSE OF ACTION IS TO REMAIN INDOORS UNTIL THE STORMS 
HAVE PASSED.

TO REPORT SEVERE WEATHER SUCH AS HAIL...DOWNED TREES...LIMBS...AND
POWER LINES...PLEASE CONTACT THE CHARLESTON NATIONAL WEATHER SERVICE
TOLL FREE AT 1-888-383-2024 OR EMAIL YOUR REPORTS TO
CHS.SKYWARN@NOAA.GOV.

LAT...LON 3350 7996 3344 7988 3326 7997 3328 8027
      3336 8024 3339 8025 3340 8023 3344 8023
      3346 8015 3348 8016 3350 8013 3351 8008
TIME...MOT...LOC 1906Z 204DEG 10KT 3346 8014

$$

The office that day

Everything else NWS Charleston, SC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 4:20 AM EDTDense Fog AdvisoryCHSAllendale, Berkeley, Colleton, Dorchester, Hampton5 hr
Apr 21, 12:31 PM EDTSpecial Weather StatementCHSBerkeley44 min
Apr 21, 1:16 PM EDTSpecial Weather StatementCHSBerkeley44 min
Apr 21, 1:19 PM EDTSevere Thunderstorm WarningCHSBerkeley41 min
Apr 21, 1:58 PM EDTSevere Thunderstorm WarningCHSBerkeley31 min
Apr 21, 2:40 PM EDTSpecial Weather StatementCHSBerkeley35 min
Apr 21, 3:29 PM EDTSpecial Weather StatementCHSBerkeley31 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2012Every severe thunderstorm warning in 2012

Sources

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