Alert archive / Alabama / Tornado Watches in 2010

Tornado Watch 9

January 24, 201028 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida; 5 counties in Mississippi

The Storm Prediction Center issued this tornado watch at Jan 24, 2010, 6:28 AM CST for 28 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida; 5 counties in Mississippi. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jan 24, 2010, 6:28 AM CST (12:28 UTC)
Expired: Jan 24, 2010, 12:55 PM CST
In force: 6 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1 in
Strongest gust expected: 60 kt

All 36 counties

Autauga County, AL, Baldwin County, AL, Bullock County, AL, Butler County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Conecuh County, AL, Coosa County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Greene County, AL, Hale County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Sumter County, AL, Tallapoosa County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, George County, MS, Greene County, MS, Perry County, MS, Stone County, MS, Wayne County, MS

The radar

The Mobile radar (KMOB), 75 km from the middle of the area, began a volume at 12:30 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: 30%
One or more gusts of 65 knots or more: 20%
Ten or more severe hail reports: 10%
One or more hailstones of 2 inches or more: 5%
Six or more combined severe hail and wind reports: 60%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Jan 24, 6:45 AM CST	Tornado Warning	MOB	Choctaw, Clarke	45 min
Jan 24, 7:00 AM CST	Tornado Warning	BMX	Marengo	45 min
Jan 24, 7:11 AM CST	Severe Thunderstorm Warning	MOB	Choctaw	37 min
Jan 24, 7:53 AM CST	Severe Thunderstorm Warning	BMX	Bibb, Chilton, Jefferson, Perry, Shelby	31 min
Jan 24, 9:31 AM CST	Tornado Warning	BMX	Autauga, Chilton, Coosa	29 min
Jan 24, 9:33 AM CST	Severe Thunderstorm Warning	MOB	Clarke, Monroe, Wilcox	50 min
Jan 24, 10:01 AM CST	Severe Thunderstorm Warning	BMX	Chilton, Coosa	29 min
Jan 24, 11:04 AM CST	Severe Thunderstorm Warning	MOB	Conecuh, Monroe	41 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

Slidell Radar S, LA (KSIL), launched 12:00Z, 0.5 hours before the alert went out and 210 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: 738 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 457 m above ground
0-6 km bulk shear: 62 kt
0-1 km storm-relative helicity: 323 m²/s²
0-3 km storm-relative helicity: 346 m²/s²
Significant tornado parameter: 1.4
Supercell composite: 6.7

Open this sounding in Storm Lab

The text

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

264 
WWUS20 KWNS 241229
SEL9
SPC WW 241229
ALZ000-FLZ000-MSZ000-CWZ000-241900-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 9
NWS STORM PREDICTION CENTER NORMAN OK
630 AM CST SUN JAN 24 2010

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

       CENTRAL AND SOUTHERN ALABAMA
       WESTERN FLORIDA PANHANDLE
       SOUTHEAST MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING AND AFTERNOON FROM 630 AM UNTIL 100
PM CST.

TORNADOES...HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 80 STATUTE
MILES EAST AND WEST OF A LINE FROM 30 MILES SOUTHEAST OF MOBILE
ALABAMA TO 20 MILES NORTH NORTHWEST OF SELMA ALABAMA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU9).

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.

DISCUSSION...LOW-LEVEL MOISTURE CONTINUES TO INCREASE /MID 60S
DEWPOINTS/ AS A WARM FRONT LIFTS NWD ACROSS SRN AL AND THE FL
PANHANDLE.  THIS MOISTENING WILL SUPPORT MLCAPE VALUES TO NEAR 500
J/KG WITH CONVECTION ROOTED AT THE SURFACE...IN AN ENVIRONMENT OF
VERY STRONG LOW-LEVEL AND DEEP-LAYER VERTICAL SHEAR.  GIVEN THE
GRADUAL INCREASE IN THUNDERSTORMS OBSERVED ACROSS SE MS/SW AL...IT
APPEARS THAT THE THREAT FOR DAMAGING WINDS AND A COUPLE OF TORNADOES
WILL LIKEWISE INCREASE THROUGH THE MORNING.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCH. EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400.
MEAN STORM MOTION VECTOR 23045.


...THOMPSON

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 24, 6:01 AM CST	Mesoscale Discussion	SPC	Autauga, Baldwin, Bibb, Butler, Choctaw, Clarke and 11 more	119 min
Jan 24, 10:25 AM CST	Mesoscale Discussion	SPC	Autauga, Barbour, Bullock, Butler, Chambers, Clay and 17 more	65 min
Jan 24, 11:26 AM CST	Tornado Watch	SPC	Baldwin, Barbour, Bullock, Butler, Chambers, Clay and 21 more	5 hr
Jan 24, 1:51 PM CST	Mesoscale Discussion	SPC	Baldwin, Barbour, Bullock, Butler, Chambers, Clay and 19 more	54 min
Jan 24, 4:18 PM CST	Tornado Watch	SPC	Barbour, Bullock, Coffee, Dale, Geneva, Henry and 3 more	7 hr
Jan 24, 5:21 PM CST	Mesoscale Discussion	SPC	Henry, Houston	84 min
Jan 23, 6:40 PM CST	Mesoscale Discussion	SPC	Bolivar, Coahoma, DeSoto, Issaquena, Leflore, Marshall and 8 more	95 min
Jan 23, 11:54 PM CST	Mesoscale Discussion	SPC	Amite, Clarke, Copiah, Covington, Forrest, George and 26 more	96 min

Nearby

Tornado Watches in Alabama, 2010 Tornado Watches in Mississippi, 2010 Tornado Watches in Florida, 2010 Every tornado watch in 2010

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.