Alert archive / Mississippi / Tornado Watches in 2012

Tornado Watch 50

February 29, 201221 counties in Alabama; 22 counties in Mississippi; Franklin County, Lincoln County, Moore County, Tennessee

The Storm Prediction Center issued this tornado watch at Feb 29, 2012, 1:48 PM CST for 21 counties in Alabama; 22 counties in Mississippi; Franklin County, Lincoln County, Moore County, Tennessee. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Feb 29, 2012, 1:48 PM CST (19:48 UTC)
Expired
Feb 29, 2012, 9:00 PM CST
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt
All 46 counties

Blount County, AL, Cherokee County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, St. Clair County, AL, Walker County, AL, Winston County, AL, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Coahoma County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Yalobusha County, MS, Franklin County, TN, Lincoln County, TN, Moore County, TN

The radar

The Columbus AFB radar (KGWX), 76 km from the middle of the area, began a volume at 19:47 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
60%
One or more EF2 to EF5 tornadoes
40%
Ten or more severe wind reports
60%
One or more gusts of 65 knots or more
40%
Ten or more severe hail reports
40%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Feb 29, 4:05 PM CSTSevere Thunderstorm WarningMEGChickasaw, Monroe42 min
Feb 29, 4:29 PM CSTSevere Thunderstorm WarningBMXFayette, Lamar, Marion46 min
Feb 29, 4:32 PM CSTTornado WarningMEGMonroe13 min
Feb 29, 4:57 PM CSTTornado WarningBMXFayette, Marion, Walker14 min
Feb 29, 5:01 PM CSTSevere Thunderstorm WarningBMXFayette, Walker44 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

Little Rock, AR (KLZK), launched 12:00Z, 7.8 hours before the alert went out and 111 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, Little Rock, AR at 12:00Z on 2012-02-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1168 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, Little Rock, AR at 12:00Z on 2012-02-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 289 square meters per square second.1939587897117136Sfc1 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
1168 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
535 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
289 m²/s²
0-3 km storm-relative helicity
292 m²/s²
Significant tornado parameter
2.3
Supercell composite
8.5

Open this sounding in Storm Lab

The text

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

536 
WWUS20 KWNS 291949
SEL0
SPC WW 291949
ALZ000-MSZ000-TNZ000-010300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 50
NWS STORM PREDICTION CENTER NORMAN OK
150 PM CST WED FEB 29 2012

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

       NORTHERN ALABAMA
       NORTHERN MISSISSIPPI
       SOUTHERN-MIDDLE TENNESSEE

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 150 PM UNTIL
900 PM CST.

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 55 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 20 MILES NORTH OF GREENVILLE
MISSISSIPPI TO 70 MILES EAST NORTHEAST OF HUNTSVILLE ALABAMA.
FOR A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
OUTLINE UPDATE (WOUS64 KWNS WOU0).

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 48...WW 49...

DISCUSSION...TSTMS GRADUALLY DEVELOPING AHEAD OF COLD FRONT ACROSS
NRN MS ARE EXPECTED TO INTENSIFY THIS AFTERNOON AS THEY INTERACT
WITH A MODERATELY UNSTABLE AND STRONGLY SHEARED ENVIRONMENT.
ADDITIONAL STORMS WILL ALSO BE POSSIBLE ALONG THE COLD FRONT AS IT
ADVANCES EWD ACROSS THE MS RIVER.  SUPERCELLS AND BOWING STRUCTURES
WILL BE POSSIBLE WITH AN ATTENDANT THREAT FOR A FEW
TORNADOES...DAMAGING WINDS AND SEVERE HAIL.

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
450. MEAN STORM MOTION VECTOR 25040.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 29, 11:46 AM CSTMesoscale DiscussionSPCColbert, Franklin, Lamar, Lauderdale, Lawrence, Marion89 min
Feb 28, 10:30 PM CSTTornado WatchSPCBaxter, Benton, Boone, Carroll, Conway, Crawford and 20 more6 hr
Feb 28, 11:40 PM CSTMesoscale DiscussionSPCBenton95 min
Feb 29, 12:49 AM CSTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Chicot, Clay, Cleburne and 31 more56 min
Feb 29, 3:20 AM CSTTornado WatchSPCBaxter, Clay, Cleburne, Conway, Craighead, Fulton and 20 more9 hr
Feb 29, 3:53 AM CSTMesoscale DiscussionSPCBaxter, Clay, Cleburne, Conway, Craighead, Faulkner and 20 more97 min
Feb 29, 8:07 AM CSTMesoscale DiscussionSPCClay, Craighead, Greene, Independence, Jackson, Lawrence and 2 more53 min
Feb 29, 11:11 AM CSTMesoscale DiscussionSPCCrittenden, Mississippi2 hr
Feb 29, 2:15 PM CSTSevere Thunderstorm WatchSPCAshley, Chicot6 hr
Feb 29, 3:34 PM CSTMesoscale DiscussionSPCAlcorn, Benton, Marshall116 min
Feb 29, 2:40 AM CSTMesoscale DiscussionSPCCheatham, Clay, Davidson, Dickson, Hickman, Houston and 11 more65 min
Feb 29, 4:39 AM CSTTornado WatchSPCBenton, Cheatham, Clay, Davidson, Dickson, Fentress and 14 more7 hr
Feb 29, 7:38 AM CSTMesoscale DiscussionSPCBenton, Cheatham, Clay, Davidson, DeKalb, Dickson and 15 more67 min
Feb 29, 11:31 AM CSTTornado WatchSPCAnderson, Bedford, Benton, Bledsoe, Campbell, Cannon and 68 more8 hr
Feb 29, 2:23 PM CSTMesoscale DiscussionSPCJohnson67 min
Feb 29, 4:36 PM CSTMesoscale DiscussionSPCBlount, Bradley, Carter, Cocke, Greene, Hamilton and 6 more54 min
Feb 29, 5:37 PM CSTTornado WatchSPCBlount, Bradley, Carter, Cocke, Greene, Hamilton and 10 more3 hr

Nearby

Tornado Watches in Mississippi, 2012Tornado Watches in Alabama, 2012Tornado Watches in Tennessee, 2012Every tornado watch 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.