Alert archive / South Carolina / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 267, NWS Charleston, SC

August 12, 2009Colleton County, Dorchester County, South Carolina

NWS Charleston, SC issued this severe thunderstorm warning at Aug 12, 2009, 12:17 PM EDT for Colleton County, Dorchester County, South Carolina. It was in force for 58 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 12, 2009, 12:17 PM EDT (16:17 UTC)
Expired
Aug 12, 2009, 1:15 PM EDT
In force
58 min
Issued by
NWS Charleston, SC
Area
Storm-based polygon

Counties Colleton County, SC, Dorchester County, SC

The radar

The Charleston,SC radar (KCLX), 59 km from the middle of the area, began a volume at 16:20 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.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 4.3 hours before the alert went out and 50 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 2009-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2560 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, Charleston AFB, SC at 12:00Z on 2009-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
2560 J/kg
Mixed-layer CIN
-49 J/kg
Mixed-layer LCL
985 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
67 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.0

Open this sounding in Storm Lab

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 Charleston, SC wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 12, 11:35 AM EDT, 42 minutes earlier.

Area forecast discussion, Aug 12, 11:35 AM EDT, 42 minutes before
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Hazardous weather outlook, Aug 12, 4:11 AM EDT, 8 hours 6 minutes before
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In the hours before

Special weather statement, Aug 12, 12:00 PM EDT, 17 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
1200 PM EDT WED AUG 12 2009

SCZ042-043-121630-
HAMPTON-INLAND COLLETON-
1200 PM EDT WED AUG 12 2009

...STRONG THUNDERSTORMS WILL IMPACT NORTHWESTERN COLLETON AND NORTH
CENTRAL HAMPTON COUNTIES THROUGH 1230 PM EDT...

AT 1159 AM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CAPABLE OF PRODUCING 1/2 INCH HAIL...AND STRONG
WINDS OF 40 TO 50 MPH.  THIS STORM WAS LOCATED NEAR MILEY...OR ABOUT
8 MILES NORTHEAST OF HAMPTON...MOVING NORTHEAST AT 20 MPH.

AREAS IN AND AROUND MOSELLE...MILEY...ASHTON...LODGE...CALDWELL...
COLLETON...PADGETTS...WILLIAMS...WILL BE IMPACTED THROUGH 1230 PM
EDT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ALERT FOR RAPIDLY CHANGING WEATHER CONDITIONS AS STORMS APPROACH.
BE READY TO TAKE IMMEDIATE ACTION IN CASE A SEVERE THUNDERSTORM
WARNING IS ISSUED FOR YOUR LOCATION.

&&

JAQ

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 2:09 PM EDTSevere Thunderstorm WarningCHSChatham, Effingham66 min
Aug 12, 2:15 PM EDTSevere Thunderstorm WarningCHSJenkins, Screven60 min
Aug 12, 2:58 PM EDTSpecial Marine WarningCHS62 min
Aug 12, 3:16 PM EDTSevere Thunderstorm WarningCHSBulloch, Jenkins, Screven59 min
Aug 12, 3:54 PM EDTSpecial Marine WarningCHS66 min
Aug 12, 4:21 PM EDTSevere Thunderstorm WarningCHSBryan, Chatham54 min
Aug 12, 4:23 PM EDTSpecial Marine WarningCHS67 min
Aug 12, 4:30 PM EDTSevere Thunderstorm WarningCHSBulloch, Effingham60 min
Aug 12, 5:07 PM EDTAreal Flood AdvisoryCHSChatham113 min
Aug 12, 5:11 PM EDTSevere Thunderstorm WarningCHSBryan, Chatham, Effingham48 min
Aug 12, 5:23 PM EDTSpecial Marine WarningCHS67 min
Aug 12, 6:17 PM EDTAreal Flood AdvisoryCHSChatham118 min
Aug 12, 6:23 PM EDTSpecial Marine WarningCHS67 min
Aug 12, 6:30 PM EDTFlash Flood WarningCHSChatham64 min
Aug 12, 7:00 PM EDTAreal Flood AdvisoryCHSMcIntosh2 hr
Aug 12, 7:10 PM EDTSpecial Marine WarningCHS65 min
Aug 12, 7:23 PM EDTSpecial Marine WarningCHS82 min
Aug 12, 12:59 PM EDTSevere Thunderstorm WarningCHSBerkeley, Dorchester61 min
Aug 12, 1:13 PM EDTSevere Thunderstorm WarningCHSBeaufort, Berkeley, Charleston, Colleton, Dorchester, Hampton and 1 more62 min
Aug 12, 1:56 PM EDTSevere Thunderstorm WarningCHSBerkeley, Charleston, Dorchester64 min
Aug 12, 2:32 PM EDTAreal Flood AdvisoryCHSBerkeley, Charleston, Dorchester84 min
Aug 12, 2:49 PM EDTSevere Thunderstorm WarningCHSBeaufort, Colleton, Jasper56 min
Aug 12, 4:12 PM EDTAreal Flood AdvisoryCHSBeaufort93 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2009Every severe thunderstorm warning in 2009

Sources

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