Alert archive / Alabama / Tornado Watches in 2011

Tornado Watch 3

January 1, 201116 counties in Alabama; 7 counties in Florida

The Storm Prediction Center issued this tornado watch at Jan 1, 2011, 9:51 AM CST for 16 counties in Alabama; 7 counties in Florida. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jan 1, 2011, 9:51 AM CST (15:51 UTC)
Expired: Jan 1, 2011, 1:51 PM CST
In force: 4 hr
Issued by: the Storm Prediction Center
Largest hail expected: 0.5 in
Strongest gust expected: 60 kt

All 23 counties

Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Lowndes County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Pike County, AL, Bay County, FL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL

The radar

The Eglin Afb radar (KEVX), 81 km from the middle of the area, began a volume at 15:50 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: 10%
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: 70%

Discussions around it

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

The nearest sounding before it

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 3.9 hours before the alert went out and 229 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 904 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 169 m²/s²
0-3 km storm-relative helicity: 232 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.

295 
WWUS20 KWNS 011552
SEL3
SPC WW 011552
ALZ000-FLZ000-MSZ000-CWZ000-012300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 3
NWS STORM PREDICTION CENTER NORMAN OK
1055 AM EST SAT JAN 1 2011

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

       SOUTHERN ALABAMA
       WESTERN FLORIDA PANHANDLE
       FAR SOUTHEAST MISSISSIPPI
       COASTAL WATERS

EFFECTIVE THIS SATURDAY MORNING AND EVENING FROM 1055 AM UNTIL
600 PM EST.

TORNADOES...HAIL TO 0.5 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 55 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 65 MILES EAST NORTHEAST OF
CRESTVIEW FLORIDA TO 60 MILES WEST OF PENSACOLA FLORIDA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU3).

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 2...

DISCUSSION...PRE-FRONTAL CLUSTER OF TSTMS IS EXPECTED TO PERSIST
INTO THIS AFTERNOON WITHIN A MOIST BUT NARROWING WARM SECTOR ALONG
THE NERN GULF COAST.  WIDESPREAD CLOUDS AND POOR LAPSE RATES WILL
LIMIT THE DEGREE OF INSTABILITY.  HOWEVER...THE MOIST/LOW LCL
BOUNDARY LAYER COUPLED WITH RATHER STRONG LOW-LEVEL SHEAR /REF. MOB
VWP/ WILL MAINTAIN A RISK FOR EMBEDDED SUPERCELLS CAPABLE OF A
COUPLE TORNADOES AND LOCALLY DAMAGING WIND GUSTS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
500. MEAN STORM MOTION VECTOR 24030.


...MEAD

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Dec 31, 10:46 PM CST	Tornado Watch	SPC	Fayette, Greene, Lamar, Marion, Pickens, Sumter and 3 more	5 hr
Jan 1, 1:14 AM CST	Mesoscale Discussion	SPC	Cullman, DeKalb, Jackson, Lawrence, Limestone, Madison and 2 more	61 min
Jan 1, 3:10 AM CST	Tornado Watch	SPC	Autauga, Baldwin, Bibb, Blount, Butler, Calhoun and 34 more	7 hr
Jan 1, 6:06 AM CST	Mesoscale Discussion	SPC	Bibb, Calhoun, Cherokee, Chilton, Choctaw, Clarke and 13 more	114 min
Jan 1, 9:04 AM CST	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Coffee, Conecuh, Covington and 9 more	56 min
Jan 1, 12:32 PM CST	Mesoscale Discussion	SPC	Baldwin, Bullock, Butler, Coffee, Conecuh, Covington and 7 more	88 min

Nearby

Tornado Watches in Alabama, 2011 Tornado Watches in Florida, 2011 Every 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.