Alert archive / Alabama / Tornado Watches in 2011
Tornado Watch 40
The Storm Prediction Center issued this tornado watch at Mar 5, 2011, 3:13 PM CST for 14 counties in Alabama; 10 counties in Florida. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Mar 5, 2011, 3:13 PM CST (21:13 UTC)
- Expired
- Mar 5, 2011, 10:00 PM CST
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 24 counties
Baldwin County, AL, Choctaw County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Mobile County, AL, Monroe County, AL, Washington County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Gulf County, FL, Holmes County, FL, Jackson County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL
The radar
The Mobile radar (KMOB), 118 km from the middle of the area, began a volume at 21:14 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
- 30%
- One or more EF2 to EF5 tornadoes
- 10%
- Ten or more severe wind reports
- 40%
- 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
3 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 5, 3:23 PM CST | Flash Flood Warning | MOB | Choctaw, Washington | 3 hr |
| Mar 5, 4:17 PM CST | Severe Thunderstorm Warning | MOB | Baldwin, Mobile | 58 min |
| Mar 5, 7:45 PM CST | Severe Thunderstorm Warning | TAE | Bay, Walton, Washington | 45 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
Birmingham, AL (KBMX), launched 12:00Z, 9.2 hours before the alert went out and 238 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 447 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 299 m²/s²
- 0-3 km storm-relative helicity
- 320 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
068
WWUS20 KWNS 052116
SEL0
SPC WW 052116
ALZ000-FLZ000-CWZ000-060400-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 40
NWS STORM PREDICTION CENTER NORMAN OK
315 PM CST SAT MAR 5 2011
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
PARTS OF SOUTHERN ALABAMA
WESTERN FLORIDA PANHANDLE
COASTAL WATERS
EFFECTIVE THIS SATURDAY AFTERNOON AND EVENING FROM 315 PM UNTIL
1000 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 65 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 35 MILES NORTH NORTHWEST OF
MOBILE ALABAMA TO 30 MILES SOUTH SOUTHEAST OF MARIANNA FLORIDA.
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...THIS TORNADO WATCH REPLACES TORNADO
WATCH NUMBER 39. WATCH NUMBER 39 WILL NOT BE IN EFFECT AFTER 315
PM CST.
DISCUSSION...SEVERE THUNDERSTORMS THAT MOVED ACROSS SRN LA ARE
CONTINUING EWD AS THE STRONG UPPER TROUGH APPROACHES FROM THE W.
WHILE THE AIR MASS AHEAD OF THE STORMS IS NOT QUITE AS UNSTABLE AS
EARLIER OVER LA...SHEAR PROFILES REMAIN VERY FAVORABLE FOR SUPERCELL
POTENTIAL AS WELL AS MAINTAINING THE CURRENT SQUALL LINE. GREATEST
SEVERE THREAT WILL BE COASTAL AREAS AND OFFSHORE WHERE INSTABILITY
IS MOST FAVORABLE.
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 450.
MEAN STORM MOTION VECTOR 24035.
...HALESSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 5, 8:40 AM CST | Mesoscale Discussion | SPC | Mobile | 65 min |
| Mar 5, 8:54 AM CST | Tornado Watch | SPC | Baldwin, Choctaw, Clarke, Mobile, Washington | 7 hr |
| Mar 5, 1:31 PM CST | Mesoscale Discussion | SPC | Baldwin, Butler, Coffee, Conecuh, Covington, Crenshaw and 5 more | 89 min |
Nearby
Tornado Watches in Alabama, 2011Tornado Watches in Florida, 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.