Alert archive / Alabama / Tornado Watches in 2009

Tornado Watch 148

April 13, 20094 states

The Storm Prediction Center issued this tornado watch at Apr 13, 2009, 2:33 AM CDT for 4 states. It was in force for 7 hr.

The area

The outline as issued.

The facts

Issued
Apr 13, 2009, 2:33 AM CDT (07:33 UTC)
Expired
Apr 13, 2009, 9:18 AM CDT
In force
7 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 51 counties

Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Escambia County, AL, Geneva County, AL, Henry County, AL, Houston County, AL, Macon County, AL, Mobile County, AL, Monroe County, AL, Pike County, AL, Russell County, AL, Washington County, AL, Bay County, FL, Calhoun County, FL, Escambia County, FL, Holmes County, FL, Jackson County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Washington County, FL, Baker County, GA, Calhoun County, GA, Chattahoochee County, GA, Clay County, GA, Dougherty County, GA, Early County, GA, Lee County, GA, Marion County, GA, Miller County, GA, Muscogee County, GA, Quitman County, GA, Randolph County, GA, Seminole County, GA, Stewart County, GA, Terrell County, GA, Webster County, GA, George County, MS, Greene County, MS, Hancock County, MS, Harrison County, MS, Jackson County, MS, Stone County, MS

The radar

The Mobile radar (KMOB), 74 km from the middle of the area, began a volume at 07:35 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
5%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Apr 13, 2:35 AM CDTSevere Thunderstorm WarningMOBMobile40 min
Apr 13, 2:52 AM CDTSevere Thunderstorm WarningMOBClarke, Washington53 min
Apr 13, 3:00 AM CDTSevere Thunderstorm WarningMOBConecuh, Monroe45 min
Apr 13, 3:14 AM CDTSevere Thunderstorm WarningLIXHarrison23 min
Apr 13, 3:50 AM CDTFlash Flood WarningMOBBaldwin, Clarke, Mobile, Monroe, Washington3 hr
Apr 13, 4:16 AM CDTSevere Thunderstorm WarningMOBBaldwin, Escambia29 min
Apr 13, 4:30 AM CDTSevere Thunderstorm WarningBMXBarbour, Bullock, Russell45 min
Apr 13, 4:36 AM CDTSevere Thunderstorm WarningMOBBaldwin, Escambia39 min
Apr 13, 4:44 AM CDTTornado WarningMOBEscambia21 min
Apr 13, 4:53 AM CDTTornado WarningBMXBarbour, Russell27 min
Apr 13, 5:10 AM CDTSevere Thunderstorm WarningMOBConecuh, Escambia36 min
Apr 13, 5:23 AM CDTSevere Thunderstorm WarningFFCChattahoochee, Stewart39 min
Apr 13, 5:42 AM CDTSevere Thunderstorm WarningMOBConecuh, Covington, Escambia33 min
Apr 13, 6:27 AM CDTSevere Thunderstorm WarningMOBCovington33 min
Apr 13, 6:56 AM CDTSevere Thunderstorm WarningMOBCovington24 min
Apr 13, 7:09 AM CDTSevere Thunderstorm WarningTAEGeneva36 min
Apr 13, 7:12 AM CDTFlash Flood WarningMOBBaldwin, Conecuh, Covington, Escambia, Mobile3 hr
Apr 13, 7:33 AM CDTSevere Thunderstorm WarningMOBBaldwin, Escambia42 min
Apr 13, 7:43 AM CDTSevere Thunderstorm WarningTAEDale, Geneva, Houston47 min
Apr 13, 8:14 AM CDTSevere Thunderstorm WarningTAEHenry46 min
Apr 13, 8:14 AM CDTTornado WarningTAEHouston31 min
Apr 13, 8:23 AM CDTSevere Thunderstorm WarningTAEHenry, Houston37 min
Apr 13, 8:35 AM CDTSevere Thunderstorm WarningMOBBaldwin, Mobile40 min
Apr 13, 9:10 AM CDTSevere Thunderstorm WarningMOBCovington50 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 00:00Z, 7.6 hours before the alert went out and 220 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, Slidell Radar S, LA at 00:00Z on 2009-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1395 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Slidell Radar S, LA at 00:00Z on 2009-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 485 square meters per square second.1939587897Sfc1 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
1395 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
497 m above ground
0-6 km bulk shear
73 kt
0-1 km storm-relative helicity
485 m²/s²
0-3 km storm-relative helicity
608 m²/s²
Significant tornado parameter
5.0
Supercell composite
19.5

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 8:07 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Butler, Chilton, Choctaw, Clarke and 12 more53 min
Apr 12, 8:30 PM CDTTornado WatchSPCChoctaw, Clarke, Greene, Hale, Marengo, Mobile and 2 more6 hr
Apr 12, 10:42 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 33 more93 min
Apr 12, 11:01 PM CDTTornado WatchSPCAutauga, Baldwin, Butler, Conecuh, Covington, Crenshaw and 8 more4 hr
Apr 13, 1:57 AM CDTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Butler, Coffee, Conecuh and 13 more63 min
Apr 13, 4:32 AM CDTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Butler, Coffee, Conecuh and 10 more58 min
Apr 13, 7:27 AM CDTMesoscale DiscussionSPCBaldwin, Coffee, Covington, Dale, Escambia, Geneva and 3 more2 hr
Apr 13, 9:12 AM CDTTornado WatchSPCCoffee, Covington, Dale, Escambia, Geneva, Henry and 1 more9 hr
Apr 13, 11:15 AM CDTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Butler, Clarke, Coffee and 11 more90 min
Apr 13, 12:09 PM CDTMesoscale DiscussionSPCColbert, Franklin, Lauderdale, Lawrence, Limestone, Marion and 2 more66 min
Apr 13, 12:58 PM CDTTornado WatchSPCColbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale and 5 more7 hr
Apr 13, 4:16 PM CDTSevere Thunderstorm WatchSPCChoctaw4 hr
Apr 13, 5:52 PM CDTMesoscale DiscussionSPCBlount, Cullman, DeKalb, Etowah, Fayette, Jackson and 10 more53 min
Apr 13, 6:55 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Clarke, Dallas, Greene and 9 more95 min
Apr 13, 11:32 AM CDTTornado WatchSPCBaker, Bradford, Clay, Columbia, Duval, Gilchrist and 5 more6 hr
Apr 13, 5:22 PM CDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Citrus, Clay, Columbia and 18 more83 min
Apr 13, 5:53 PM CDTTornado WatchSPCAlachua, Baker, Bradford, Calhoun, Clay, Columbia and 22 more5 hr
Apr 13, 1:39 PM CDTMesoscale DiscussionSPCAdams, Amite, Copiah, Covington, Forrest, Franklin and 14 more66 min

Nearby

Tornado Watches in Alabama, 2009Tornado Watches in Georgia, 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.