Alert archive / Alabama / Tornado Watches in 2009
Tornado Watch 147
The Storm Prediction Center issued this tornado watch at Apr 12, 2009, 11:01 PM CDT for 14 counties in Alabama; Escambia County, Okaloosa County, Santa Rosa County, Florida. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 12, 2009, 11:01 PM CDT (04:01 UTC)
- Expired
- Apr 13, 2009, 2:33 AM CDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
Counties Autauga County, AL, Baldwin County, AL, Butler County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Lowndes County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL
The radar
The Mobile radar (KMOB), 150 km from the middle of the area, began a volume at 04:02 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
- 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
- 50%
Warnings issued inside it
6 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 11:17 PM CDT | Severe Thunderstorm Warning | MOB | Clarke, Monroe, Washington, Wilcox | 58 min |
| Apr 12, 11:55 PM CDT | Severe Thunderstorm Warning | BMX | Dallas | 35 min |
| Apr 13, 12:06 AM CDT | Severe Thunderstorm Warning | MOB | Butler, Wilcox | 39 min |
| Apr 13, 12:25 AM CDT | Severe Thunderstorm Warning | BMX | Dallas, Lowndes, Montgomery | 35 min |
| Apr 13, 1:00 AM CDT | Severe Thunderstorm Warning | BMX | Lowndes, Montgomery | 45 min |
| Apr 13, 2:15 AM CDT | Severe Thunderstorm Warning | MOB | Butler, Crenshaw | 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 00:00Z, 4.0 hours before the alert went out and 176 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
- 1755 m above ground
- 0-6 km bulk shear
- 34 kt
- 0-1 km storm-relative helicity
- 140 m²/s²
- 0-3 km storm-relative helicity
- 406 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
579
WWUS20 KWNS 130401
SEL7
SPC WW 130401
ALZ000-FLZ000-CWZ000-131000-
URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 147
NWS STORM PREDICTION CENTER NORMAN OK
1105 PM CDT SUN APR 12 2009
THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF
SOUTHERN ALABAMA
EXTREME WESTERN FLORIDA PANHANDLE
COASTAL WATERS
EFFECTIVE THIS SUNDAY NIGHT AND MONDAY MORNING FROM 1105 PM UNTIL
500 AM CDT.
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 55 STATUTE
MILES EAST AND WEST OF A LINE FROM 15 MILES NORTH NORTHWEST OF
MONTGOMERY ALABAMA TO 25 MILES WEST SOUTHWEST OF PENSACOLA
FLORIDA. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU7).
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 146...
DISCUSSION...A LINEAR MCS WITH EMBEDDED BOW/SUPERCELL STRUCTURES
WILL CONTINUE TO MOVE EWD FROM SE MS INTO SW/SRN AL ALONG THE WARM
FRONT/NRN EDGE OF THE SURFACE MOIST SECTOR. THOUGH THE LINEAR
CONFIGURATION OF THE CONVECTION SUGGESTS THAT DAMAGING WINDS AND
HEAVY RAINFALL WILL BE THE MAIN THREATS...LOW-LEVEL SHEAR REMAINS
QUITE STRONG AND AN ISOLATED TORNADO OR TWO WILL STILL BE POSSIBLE
THROUGH THE EARLY MORNING HOURS.
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 500.
MEAN STORM MOTION VECTOR 27030.
...THOMPSONSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 12, 8:07 PM CDT | Mesoscale Discussion | SPC | Autauga, Bibb, Butler, Chilton, Choctaw, Clarke and 12 more | 53 min |
| Apr 12, 8:30 PM CDT | Tornado Watch | SPC | Choctaw, Clarke, Greene, Hale, Marengo, Mobile and 2 more | 6 hr |
| Apr 12, 10:42 PM CDT | Mesoscale Discussion | SPC | Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 33 more | 93 min |
| Apr 13, 1:57 AM CDT | Mesoscale Discussion | SPC | Baldwin, Barbour, Bullock, Butler, Coffee, Conecuh and 13 more | 63 min |
| Apr 13, 2:33 AM CDT | Tornado Watch | SPC | Baldwin, Barbour, Bullock, Butler, Clarke, Coffee and 14 more | 7 hr |
| Apr 13, 4:32 AM CDT | Mesoscale Discussion | SPC | Baldwin, Barbour, Bullock, Butler, Coffee, Conecuh and 10 more | 58 min |
| Apr 13, 7:27 AM CDT | Mesoscale Discussion | SPC | Baldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more | 2 hr |
| Apr 13, 9:12 AM CDT | Tornado Watch | SPC | Coffee, Covington, Dale, Escambia, Geneva, Henry and 1 more | 9 hr |
| Apr 13, 11:15 AM CDT | Mesoscale Discussion | SPC | Baldwin, Barbour, Bullock, Butler, Clarke, Coffee and 11 more | 90 min |
| Apr 13, 12:09 PM CDT | Mesoscale Discussion | SPC | Colbert, Franklin, Lauderdale, Lawrence, Limestone, Marion and 2 more | 66 min |
| Apr 13, 12:58 PM CDT | Tornado Watch | SPC | Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more | 7 hr |
| Apr 13, 4:16 PM CDT | Severe Thunderstorm Watch | SPC | Choctaw | 4 hr |
| Apr 13, 5:52 PM CDT | Mesoscale Discussion | SPC | Blount, Cullman, DeKalb, Etowah, Fayette, Jackson and 10 more | 53 min |
| Apr 13, 6:55 PM CDT | Mesoscale Discussion | SPC | Bibb, Chilton, Choctaw, Clarke, Dallas, Greene and 9 more | 95 min |
| Apr 13, 11:32 AM CDT | Tornado Watch | SPC | Baker, Bradford, Clay, Columbia, Duval, Gilchrist and 5 more | 6 hr |
| Apr 13, 5:22 PM CDT | Mesoscale Discussion | SPC | Alachua, Baker, Bradford, Citrus, Clay, Columbia and 18 more | 83 min |
| Apr 13, 5:53 PM CDT | Tornado Watch | SPC | Alachua, Baker, Bradford, Calhoun, Clay, Columbia and 22 more | 5 hr |
Nearby
Tornado Watches in Alabama, 2009Tornado Watches in Florida, 2009Every tornado watch in 2009
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.