Alert archive / North Carolina / Tornado Watches in 2011

Tornado Watch 252

April 28, 201112 counties in Georgia; 21 counties in North Carolina; 16 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Apr 28, 2011, 8:48 AM EDT for 12 counties in Georgia; 21 counties in North Carolina; 16 counties in South Carolina. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 28, 2011, 8:48 AM EDT (12:48 UTC)
Expired
Apr 28, 2011, 4:00 PM EDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 49 counties

Bryan County, GA, Bulloch County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Screven County, GA, Tattnall County, GA, Beaufort County, NC, Bladen County, NC, Brunswick County, NC, Carteret County, NC, Columbus County, NC, Craven County, NC, Dare County, NC, Duplin County, NC, Greene County, NC, Hyde County, NC, Jones County, NC, Lenoir County, NC, Martin County, NC, New Hanover County, NC, Onslow County, NC, Pamlico County, NC, Pender County, NC, Pitt County, NC, Robeson County, NC, Tyrrell County, NC, Washington County, NC, Allendale County, SC, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Marlboro County, SC, Williamsburg County, SC

The radar

The Wilmington radar (KLTX), 106 km from the middle of the area, began a volume at 12:49 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 SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
20%
One or more hailstones of 2 inches or more
10%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

18 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Apr 28, 9:37 AM EDTSevere Thunderstorm WarningILMFlorence, Marion, Williamsburg53 min
Apr 28, 10:16 AM EDTTornado WarningILMDillon, Florence, Horry, Marion44 min
Apr 28, 10:41 AM EDTSevere Thunderstorm WarningILMDillon, Florence, Horry, Marion64 min
Apr 28, 11:33 AM EDTSevere Thunderstorm WarningILMRobeson57 min
Apr 28, 12:15 PM EDTTornado WarningILMRobeson34 min
Apr 28, 12:42 PM EDTTornado WarningILMBladen, Columbus, Robeson48 min
Apr 28, 1:02 PM EDTTornado WarningILMBladen, Robeson43 min
Apr 28, 1:41 PM EDTTornado WarningMHXDuplin, Lenoir49 min
Apr 28, 2:01 PM EDTTornado WarningILMBladen44 min
Apr 28, 2:24 PM EDTSevere Thunderstorm WarningILMColumbus, Robeson51 min
Apr 28, 2:26 PM EDTTornado WarningMHXDuplin49 min
Apr 28, 2:52 PM EDTTornado WarningILMBladen, Columbus38 min
Apr 28, 3:10 PM EDTTornado WarningMHXDuplin, Lenoir50 min
Apr 28, 3:24 PM EDTSevere Thunderstorm WarningILMBladen, Columbus, Pender51 min
Apr 28, 3:29 PM EDTTornado WarningMHXBeaufort, Greene, Martin, Pitt46 min
Apr 28, 3:37 PM EDTTornado WarningILMBladen, Columbus, Pender38 min
Apr 28, 3:48 PM EDTTornado WarningMHXCraven, Duplin, Jones, Lenoir42 min
Apr 28, 3:57 PM EDTSevere Thunderstorm WarningCHSMcIntosh48 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 0.8 hours before the alert went out and 86 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 2011-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1847 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 2011-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 221 square meters per square second.193958Sfc1 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
1847 J/kg
Mixed-layer CIN
-17 J/kg
Mixed-layer LCL
685 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
221 m²/s²
0-3 km storm-relative helicity
251 m²/s²
Significant tornado parameter
1.8
Supercell composite
10.6

Open this sounding in Storm Lab

The text

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

735 
WWUS20 KWNS 281249
SEL2
SPC WW 281249
GAZ000-NCZ000-SCZ000-CWZ000-282000-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 252
NWS STORM PREDICTION CENTER NORMAN OK
850 AM EDT THU APR 28 2011

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       SOUTHEAST GEORGIA
       EASTERN NORTH CAROLINA
       EASTERN SOUTH CAROLINA
       COASTAL WATERS

EFFECTIVE THIS THURSDAY MORNING AND AFTERNOON FROM 850 AM UNTIL
400 PM EDT.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES SOUTH OF SAVANNAH
GEORGIA TO 75 MILES NORTHEAST OF NEW BERN NORTH CAROLINA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU2).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 249...WW 250...WW 251...

DISCUSSION...BROKEN BAND OF PRE-FRONTAL CONVECTION WILL PERSIST FOR
THE NEXT FEW HOURS...WITH ADDITIONAL DEVELOPMENT POSSIBLE CLOSER TO
THE COAST AS DAYTIME HEATING PROCEEDS.  THE ENVIRONMENT IS EXPECTED
TO REMAIN MODERATELY UNSTABLE /MLCAPE AOA 1500 J PER KG/...WITH
SUFFICIENT VERTICAL SHEAR TO MAINTAIN A THREAT FOR DAMAGING
WINDS/LARGE HAIL...AS WELL AS A COUPLE OF TORNADOES WITH EMBEDDED
SUPERCELLS/BOWS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24035.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 27, 8:55 PM EDTMesoscale DiscussionSPCChattooga, Walker65 min
Apr 28, 12:09 AM EDTMesoscale DiscussionSPCBanks, Barrow, Bartow, Bibb, Butts, Carroll and 65 more36 min
Apr 28, 12:56 AM EDTTornado WatchSPCBaldwin, Banks, Barrow, Bibb, Bleckley, Burke and 80 more4 hr
Apr 28, 2:22 AM EDTMesoscale DiscussionSPCBaker, Calhoun, Clay, Early, Miller, Quitman and 2 more83 min
Apr 28, 3:30 AM EDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Burke, Chattahoochee, Columbia and 30 more90 min
Apr 28, 4:30 AM EDTTornado WatchSPCBaldwin, Bibb, Bleckley, Bulloch, Burke, Candler and 37 more10 hr
Apr 28, 8:05 AM EDTMesoscale DiscussionSPCBurke, Candler, Dodge, Emanuel, Jefferson, Jenkins and 5 more85 min
Apr 28, 9:47 AM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Brantley, Camden, Charlton and 8 more9 hr
Apr 28, 11:22 AM EDTMesoscale DiscussionSPCBulloch, Burke, Candler, Chatham, Effingham, Emanuel and 2 more53 min
Apr 28, 12:19 PM EDTMesoscale DiscussionSPCAppling, Bacon, Brantley, Camden, Charlton, Clinch and 10 more56 min
Apr 27, 10:12 PM EDTMesoscale DiscussionSPCAlleghany, Ashe, Forsyth, Rockingham, Stokes, Surry and 3 more63 min
Apr 28, 12:27 AM EDTMesoscale DiscussionSPCAlamance, Alleghany, Ashe, Caswell, Davidson, Davie and 11 more63 min
Apr 28, 12:41 AM EDTTornado WatchSPCAlamance, Alleghany, Ashe, Caswell, Davidson, Forsyth and 10 more7 hr
Apr 28, 7:38 AM EDTTornado WatchSPCBertie, Camden, Caswell, Chowan, Currituck, Gates and 9 more7 hr
Apr 28, 2:41 PM EDTTornado WatchSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 21 more6 hr
Apr 28, 3:19 PM EDTTornado WatchSPCBladen, Brunswick, Columbus, New Hanover, Pender4 hr
Apr 28, 6:33 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 20 more57 min

Nearby

Tornado Watches in North Carolina, 2011Tornado Watches in South Carolina, 2011Tornado Watches in Georgia, 2011Every tornado watch in 2011

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.