Alert archive / South Carolina / Severe Thunderstorm Warnings in 2009

Severe Thunderstorm Warning 66, NWS Charleston, SC

May 10, 2009Charleston County, Colleton County, South Carolina

NWS Charleston, SC issued this severe thunderstorm warning at May 10, 2009, 1:36 PM EDT for Charleston County, Colleton County, South Carolina. It was in force for 24 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: May 10, 2009, 1:36 PM EDT (17:36 UTC)
Expired: May 10, 2009, 2:00 PM EDT
In force: 24 min
Issued by: NWS Charleston, SC
Area: Storm-based polygon

Counties Charleston County, SC, Colleton County, SC

The radar

The Charleston,SC radar (KCLX), 72 km from the middle of the area, began a volume at 17:35 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, 5.6 hours before the alert went out and 30 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 681 J/kg
Mixed-layer CIN: -56 J/kg
Mixed-layer LCL: 1064 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 26 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

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 May 10, 10:46 AM EDT, 2 hours 50 minutes earlier.

Area forecast discussion, May 10, 10:46 AM EDT, 2 hours 50 minutes before

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Hazardous weather outlook, May 10, 9:22 AM EDT, 4 hours 14 minutes before

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE CHARLESTON SC
922 AM EDT SUN MAY 10 2009

AMZ330-350-352-354-374-GAZ087-088-099>101-114>119-137>141-SCZ040-
042>045-047>051-111000-
CHARLESTON HARBOR-
WATERS FROM SOUTH SANTEE RIVER TO EDISTO BEACH SC OUT 20 NM-
WATERS FROM EDISTO BEACH SC TO SAVANNAH GA OUT 20 NM-
WATERS FROM SAVANNAH GA TO ALTAMAHA SOUND GA OUT 20 NM...INCLUDING
GRAYS REEF NATIONAL MARINE SANCTUARY-
WATERS FROM SAVANNAH GA TO ALTAMAHA SOUND GA EXTENDING FROM 20 TO
60 NM-JENKINS-SCREVEN-CANDLER-BULLOCH-EFFINGHAM-TATTNALL-EVANS-
INLAND BRYAN-COASTAL BRYAN-INLAND CHATHAM-COASTAL CHATHAM-LONG-
INLAND LIBERTY-COASTAL LIBERTY-INLAND MCINTOSH-COASTAL MCINTOSH-
ALLENDALE-HAMPTON-INLAND COLLETON-DORCHESTER-BERKELEY-INLAND JASPER-
BEAUFORT-COASTAL COLLETON-CHARLESTON-COASTAL JASPER-
922 AM EDT SUN MAY 10 2009

...SLIGHT RISK FOR SEVERE THUNDERSTORMS TODAY...

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL
WATERS...SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

SEVERE THUNDERSTORMS...A COLD FRONT WILL STALL TODAY WITHIN A
MOIST AND VERY WARM AIRMASS OVER THE REGION. SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE AREA THIS
AFTERNOON INTO THIS EVENING. A FEW THUNDERSTORMS MAY BECOME
SEVERE...PRODUCING LARGE HAIL AT LEAST THE SIZE OF PENNIES AND
DAMAGING WIND GUSTS TO 60 MPH. SEVERE WEATHER...IF ANY...WILL
MOST LIKELY OCCUR BETWEEN 2 PM AND 10 PM.

YOU ARE URGED TO MONITOR NOAA WEATHER RADIO ALL HAZARDS OR OTHER
MEDIA OUTLETS FOR ADDITIONAL INFORMATION REGARDING POTENTIALLY
HAZARDOUS WEATHER CONDITIONS. IF YOU PLAN OUTDOOR ACTIVITIES...
REMAIN ALERT FOR THUNDERSTORMS TODAY.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO TONIGHT.

In the hours before

Special weather statement, May 10, 12:52 PM EDT, 44 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
1252 PM EDT SUN MAY 10 2009

SCZ043-048>050-101715-
BEAUFORT-CHARLESTON-COASTAL COLLETON-INLAND COLLETON-
1252 PM EDT SUN MAY 10 2009

...STRONG THUNDERSTORMS WILL IMPACT EXTREME NORTH CENTRAL BEAUFORT...
EXTREME WEST CENTRAL CHARLESTON AND CENTRAL COLLETON COUNTIES THROUGH
115 PM EDT...

AT 1251 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CAPABLE OF PRODUCING SMALL HAIL...AND GUSTY WINDS
OF 30 TO 40 MPH.  THIS STORM WAS LOCATED NEAR ASHEPOO...OR ABOUT 12
MILES SOUTHEAST OF WALTERBORO...MOVING EAST AT 30 MPH.

AREAS IN AND AROUND ASHEPOO...GREEN POND...JACKSONBORO AND RITTER
WILL BE IMPACTED THROUGH 115 PM EDT.

HAVE AN ACTION PLAN READY IN THE EVENT THIS STORM STRENGTHENS OR A
WARNING IS ISSUED. CONTINUE TO MONITOR NOAA WEATHER RADIO ALL HAZARDS
FOR THE LATEST WEATHER INFORMATION.

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.

PLEASE CONTACT THE NATIONAL WEATHER SERVICE IN CHARLESTON TOLL FREE
AT 1-888-383-2024 IF YOU OBSERVE SEVERE WEATHER SUCH AS HAIL...DOWNED
TREES...LIMBS AND POWER LINES.

Special weather statement, May 10, 1:32 PM EDT, 4 minutes before

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
132 PM EDT SUN MAY 10 2009

SCZ043-049-050-101800-
CHARLESTON-COASTAL COLLETON-INLAND COLLETON-
132 PM EDT SUN MAY 10 2009

...STRONG THUNDERSTORMS WILL IMPACT SOUTHWESTERN CHARLESTON AND EAST
CENTRAL COLLETON COUNTIES THROUGH 200 PM EDT...

AT 130 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CAPABLE OF PRODUCING SMALL HAIL...AND GUSTY WINDS
OF 30 TO 40 MPH.  THIS STORM WAS LOCATED NEAR JACKSONBORO...OR ABOUT
18 MILES NORTHWEST OF EDISTO BEACH...MOVING EAST AT 15 MPH.

AREAS IN AND AROUND ADAMS RUN...HOLLYWOOD...JACKSONBORO...MEGGETT...
RAVENEL AND YONGES ISLAND WILL BE IMPACTED THROUGH 200 PM EDT.

OTHER THUNDERSTORMS WERE DEVELOPING FROM RAVENEL TO ADAMS RUN. THESE
THUNDERSTORMS MAY ALSO INTENSIFY AND PRODUCE SMALL HAIL AND GUSTY
WINDS. THESE STORMS MAY IMPACT THE WEST ASHLEY...JOHNS ISLAND AND
JAMES ISLAND AREAS.

HAVE AN ACTION PLAN READY IN THE EVENT THIS STORM STRENGTHENS OR A
WARNING IS ISSUED. CONTINUE TO MONITOR NOAA WEATHER RADIO ALL HAZARDS
FOR THE LATEST WEATHER INFORMATION.

PLEASE CONTACT THE NATIONAL WEATHER SERVICE IN CHARLESTON TOLL FREE
AT 1-888-383-2024 IF YOU OBSERVE SEVERE WEATHER SUCH AS HAIL...DOWNED
TREES...LIMBS AND POWER LINES.

The office that day

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

Issued	Product	Office	Counties	Lasted
May 10, 2:09 PM EDT	Severe Thunderstorm Warning	CHS	Screven	34 min
May 10, 2:11 PM EDT	Special Marine Warning	CHS		64 min
May 10, 3:15 PM EDT	Special Marine Warning	CHS		60 min
May 10, 4:12 PM EDT	Special Marine Warning	CHS		93 min
May 10, 2:52 PM EDT	Severe Thunderstorm Warning	CHS	Colleton	38 min
May 10, 2:56 PM EDT	Severe Thunderstorm Warning	CHS	Beaufort, Colleton, Hampton, Jasper	35 min
May 10, 3:02 PM EDT	Severe Thunderstorm Warning	CHS	Beaufort, Charleston, Colleton	58 min
May 10, 3:34 PM EDT	Severe Thunderstorm Warning	CHS	Berkeley, Charleston	26 min
May 10, 3:56 PM EDT	Severe Thunderstorm Warning	CHS	Charleston, Colleton, Dorchester	29 min
May 10, 3:59 PM EDT	Severe Thunderstorm Warning	CHS	Colleton, Dorchester	46 min
May 10, 4:25 PM EDT	Severe Thunderstorm Warning	CHS	Berkeley, Charleston, Dorchester	50 min
May 10, 4:36 PM EDT	Areal Flood Advisory	CHS	Berkeley	54 min
May 10, 4:38 PM EDT	Severe Thunderstorm Warning	CHS	Colleton, Dorchester	37 min
May 10, 5:16 PM EDT	Severe Thunderstorm Warning	CHS	Berkeley, Charleston, Colleton, Dorchester	44 min
May 10, 5:54 PM EDT	Severe Thunderstorm Warning	CHS	Berkeley, Colleton, Dorchester	51 min
May 10, 7:04 PM EDT	Severe Thunderstorm Warning	CHS	Colleton, Dorchester	56 min
May 10, 7:42 PM EDT	Severe Thunderstorm Warning	CHS	Beaufort, Colleton	48 min

Nearby

Severe Thunderstorm Warnings in South Carolina, 2009 Every 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.