Alert archive / Alabama / Tornado Watches in 2010

Tornado Watch 93

April 24, 201040 counties in Alabama; 23 counties in Tennessee

The Storm Prediction Center issued this tornado watch at Apr 24, 2010, 8:01 AM CDT for 40 counties in Alabama; 23 counties in Tennessee. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Apr 24, 2010, 8:01 AM CDT (13:01 UTC)
Expired: Apr 24, 2010, 1:20 PM CDT
In force: 5 hr
Issued by: the Storm Prediction Center
Particularly dangerous situation: Yes
Largest hail expected: 2 in
Strongest gust expected: 60 kt

All 63 counties

Autauga County, AL, Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Clay County, AL, Colbert County, AL, Coosa County, AL, Cullman County, AL, Dallas County, AL, DeKalb County, AL, Elmore County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Greene County, AL, Hale County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Lowndes County, AL, Madison County, AL, Marengo County, AL, Marion County, AL, Marshall County, AL, Montgomery County, AL, Morgan County, AL, Perry County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Sumter County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Bedford County, TN, Benton County, TN, Cheatham County, TN, Coffee County, TN, Davidson County, TN, Dickson County, TN, Franklin County, TN, Giles County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marshall County, TN, Maury County, TN, Montgomery County, TN, Moore County, TN, Perry County, TN, Rutherford County, TN, Stewart County, TN, Wayne County, TN, Williamson County, TN

The radar

The Northeast Alabama radar (KHTX), 109 km from the middle of the area, began a volume at 13:04 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: 80%
One or more EF2 to EF5 tornadoes: 60%
Ten or more severe wind reports: 70%
One or more gusts of 65 knots or more: 60%
Ten or more severe hail reports: 70%
One or more hailstones of 2 inches or more: 50%
Six or more combined severe hail and wind reports: 95%

Warnings issued inside it

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

Issued	Product	Office	Counties	Lasted
Apr 24, 8:01 AM CDT	Severe Thunderstorm Warning	BMX	Fayette, Marion, Tuscaloosa, Walker, Winston	59 min
Apr 24, 8:11 AM CDT	Severe Thunderstorm Warning	HUN	Colbert, Franklin, Lauderdale	64 min
Apr 24, 8:13 AM CDT	Severe Thunderstorm Warning	BMX	Jefferson	47 min
Apr 24, 8:16 AM CDT	Severe Thunderstorm Warning	BMX	Lamar, Marion, Winston	44 min
Apr 24, 8:22 AM CDT	Severe Thunderstorm Warning	BMX	Greene, Hale, Marengo, Sumter	14 min
Apr 24, 8:37 AM CDT	Severe Thunderstorm Warning	BMX	Blount, Jefferson	38 min
Apr 24, 8:47 AM CDT	Severe Thunderstorm Warning	BMX	Hale, Marengo, Perry, Sumter	43 min
Apr 24, 8:50 AM CDT	Severe Thunderstorm Warning	HUN	Cullman	40 min
Apr 24, 8:56 AM CDT	Severe Thunderstorm Warning	BMX	Blount, Jefferson, St. Clair	19 min
Apr 24, 9:17 AM CDT	Severe Thunderstorm Warning	HUN	Lauderdale, Lawrence, Limestone, Morgan	28 min
Apr 24, 9:41 AM CDT	Severe Thunderstorm Warning	OHX	Giles, Lawrence, Marshall, Maury	49 min
Apr 24, 9:55 AM CDT	Severe Thunderstorm Warning	BMX	Greene, Sumter	65 min
Apr 24, 10:16 AM CDT	Severe Thunderstorm Warning	BMX	Marengo, Sumter	44 min
Apr 24, 10:23 AM CDT	Tornado Warning	BMX	Marengo, Sumter	67 min
Apr 24, 10:30 AM CDT	Severe Thunderstorm Warning	OHX	Benton, Humphreys, Perry	60 min
Apr 24, 10:40 AM CDT	Severe Thunderstorm Warning	BMX	Autauga, Chilton, Dallas, Perry	50 min
Apr 24, 11:01 AM CDT	Tornado Warning	BMX	Hale, Marengo, Sumter	44 min
Apr 24, 11:30 AM CDT	Severe Thunderstorm Warning	BMX	Bibb, Greene, Hale, Perry	45 min
Apr 24, 11:35 AM CDT	Tornado Warning	BMX	Bibb, Greene, Hale, Perry	40 min
Apr 24, 11:41 AM CDT	Severe Thunderstorm Warning	BMX	Greene, Hale, Marengo, Sumter	49 min
Apr 24, 12:28 PM CDT	Severe Thunderstorm Warning	BMX	Marengo	19 min
Apr 24, 12:34 PM CDT	Severe Thunderstorm Warning	BMX	Greene, Hale, Sumter	41 min
Apr 24, 12:45 PM CDT	Severe Thunderstorm Warning	BMX	Autauga, Chilton, Dallas, Lowndes	45 min
Apr 24, 1:06 PM CDT	Tornado Warning	HUN	Lauderdale	21 min
Apr 24, 1:17 PM CDT	Severe Thunderstorm Warning	BMX	Bibb, Hale, Tuscaloosa	43 min
Apr 24, 1:20 PM CDT	Severe Thunderstorm Warning	OHX	Davidson, Rutherford, Williamson, Wilson	25 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, 1.0 hours before the alert went out and 165 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: 276 J/kg
Mixed-layer CIN: -229 J/kg
Mixed-layer LCL: 470 m above ground
0-6 km bulk shear: 57 kt
0-1 km storm-relative helicity: 387 m²/s²
0-3 km storm-relative helicity: 386 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 8.1

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 23, 7:39 PM CDT	Mesoscale Discussion	SPC	Baldwin, Bibb, Choctaw, Clarke, Conecuh, Dallas and 12 more	36 min
Apr 23, 10:32 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Choctaw, Clarke, Dallas and 11 more	58 min
Apr 24, 2:07 AM CDT	Mesoscale Discussion	SPC	Baldwin, Butler, Clarke, Conecuh, Covington, Escambia and 3 more	53 min
Apr 24, 6:15 AM CDT	Tornado Watch	SPC	Baldwin, Butler, Choctaw, Clarke, Conecuh, Mobile and 3 more	7 hr
Apr 24, 7:43 AM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Chilton, Coosa, Cullman, Dallas and 18 more	2 hr
Apr 24, 9:31 AM CDT	Mesoscale Discussion	SPC	Colbert, Fayette, Franklin, Lamar, Lauderdale, Lawrence and 5 more	59 min
Apr 24, 10:28 AM CDT	Mesoscale Discussion	SPC	Autauga, Baldwin, Bibb, Blount, Butler, Calhoun and 32 more	92 min
Apr 24, 11:40 AM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Bullock, Butler, Calhoun and 39 more	95 min
Apr 24, 12:47 PM CDT	Tornado Watch	SPC	Baldwin, Butler, Choctaw, Clarke, Coffee, Conecuh and 11 more	7 hr
Apr 24, 1:17 PM CDT	Tornado Watch PDS	SPC	Autauga, Barbour, Bibb, Blount, Bullock, Calhoun and 44 more	8 hr
Apr 24, 2:01 PM CDT	Mesoscale Discussion	SPC	Autauga, Bibb, Blount, Chilton, Colbert, Cullman and 24 more	89 min
Apr 24, 5:48 PM CDT	Mesoscale Discussion	SPC	Autauga, Baldwin, Barbour, Bibb, Blount, Bullock and 61 more	57 min
Apr 23, 11:40 PM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Chester, Crockett, Decatur, Dyer and 21 more	65 min
Apr 24, 2:44 AM CDT	Mesoscale Discussion	SPC	Benton, Carroll, Chester, Crockett, Decatur, Dyer and 14 more	91 min
Apr 24, 6:00 AM CDT	Tornado Watch PDS	SPC	Carroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more	6 hr
Apr 24, 11:31 AM CDT	Tornado Watch PDS	SPC	Carroll, Chester, Crockett, Decatur, Dyer, Fayette and 14 more	8 hr
Apr 24, 6:15 PM CDT	Tornado Watch	SPC	Anderson, Bedford, Bledsoe, Blount, Bradley, Campbell and 53 more	8 hr

Nearby

Tornado Watches in Alabama, 2010 Tornado Watches in Tennessee, 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.