Alert archive / Georgia / Tornado Watches in 2011

Tornado Watch 64

March 26, 20119 counties in Georgia; 5 counties in South Carolina

The Storm Prediction Center issued this tornado watch at Mar 26, 2011, 7:40 PM EDT for 9 counties in Georgia; 5 counties in South Carolina. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Mar 26, 2011, 7:40 PM EDT (23:40 UTC)
Expired
Mar 26, 2011, 11:29 PM EDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt

Counties Bryan County, GA, Bulloch County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Screven County, GA, Tattnall County, GA, Allendale County, SC, Beaufort County, SC, Colleton County, SC, Hampton County, SC, Jasper County, SC

The radar

The Robins AFB radar (KJGX), 110 km from the middle of the area, began a volume at 23:41 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
20%
One or more gusts of 65 knots or more
10%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Mar 26, 8:14 PM EDTSevere Thunderstorm WarningCHSEffingham, Screven61 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, 11.7 hours before the alert went out and 212 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 2011-03-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2011-03-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1585 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
133 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

165 
WWUS20 KWNS 262341
SEL4
SPC WW 262341
GAZ000-SCZ000-270600-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 64
NWS STORM PREDICTION CENTER NORMAN OK
740 PM EDT SAT MAR 26 2011

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

       EAST-CENTRAL GEORGIA
       SOUTHERN SOUTH CAROLINA

EFFECTIVE THIS SATURDAY NIGHT AND SUNDAY MORNING FROM 740 PM
UNTIL 200 AM EDT.

TORNADOES...HAIL TO 2 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 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 65 MILES NORTH NORTHEAST OF
VIDALIA GEORGIA TO 45 MILES SOUTH SOUTHEAST OF VIDALIA GEORGIA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU4).

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 62...WW 63...

DISCUSSION...SUPERCELLS OVER E-CNTRL GA HAVE RECENTLY INTENSIFIED
AND ARE EXPECTED TO CONTINUE EWD TOWARD THE ATLANTIC COAST TONIGHT.
STRENGTHENING SWLY LLJ /PER CHARLESTON VWP/ WILL NOT ONLY SERVE TO
ADVECT A MORE MOIST UNSTABLE AIR MASS INTO AREA AHEAD OF ONGOING
STORMS...BUT ALSO RESULT IN AN INCREASE IN LOW-LEVEL SHEAR.  AS
SUCH...THE RISK FOR A COUPLE OF TORNADOES IN ADDITION TO DAMAGING
WINDS AND HAIL WILL EXIST.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 2 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 27035.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 26, 12:25 PM EDTMesoscale DiscussionSPCHeard95 min
Mar 26, 12:33 PM EDTMesoscale DiscussionSPCAtkinson, Bacon, Baker, Ben Hill, Berrien, Brooks and 18 more57 min
Mar 26, 1:15 PM EDTTornado WatchSPCBaker, Baldwin, Ben Hill, Berrien, Bibb, Bleckley and 74 more8 hr
Mar 26, 3:23 PM EDTMesoscale DiscussionSPCAtkinson, Bacon, Baker, Baldwin, Ben Hill, Berrien and 79 more97 min
Mar 26, 3:38 PM EDTMesoscale DiscussionSPCAppling, Bacon, Bryan, Bulloch, Candler, Effingham and 11 more97 min
Mar 26, 7:59 PM EDTMesoscale DiscussionSPCBaker, Baldwin, Ben Hill, Berrien, Bibb, Bleckley and 75 more91 min

Nearby

Tornado Watches in Georgia, 2011Tornado Watches in South Carolina, 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.