Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 370

April 2, 200951 counties in Alabama; 12 counties in Mississippi; 10 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at Apr 2, 2009, 1:09 PM CDT for 51 counties in Alabama; 12 counties in Mississippi; 10 counties in Tennessee. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
Apr 2, 2009, 1:09 PM CDT (18:09 UTC)
Expired
Apr 2, 2009, 2:15 PM CDT
In force
66 min
Issued by
the Storm Prediction Center
All 73 counties

Autauga County, AL, Baldwin County, AL, Bibb County, AL, Blount County, AL, Butler County, AL, Calhoun County, AL, Cherokee County, AL, Chilton County, AL, Choctaw County, AL, Clarke County, AL, Clay County, AL, Colbert County, AL, Conecuh County, AL, Coosa County, AL, Crenshaw County, AL, Cullman County, AL, Dallas County, AL, DeKalb County, AL, Elmore County, AL, Escambia 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, Mobile County, AL, Monroe 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, Washington County, AL, Wilcox County, AL, Winston County, AL, Clarke County, MS, George County, MS, Greene County, MS, Harrison County, MS, Jackson County, MS, Kemper County, MS, Lauderdale County, MS, Lowndes County, MS, Noxubee County, MS, Perry County, MS, Stone County, MS, Wayne County, MS, Bedford County, TN, Coffee County, TN, Franklin County, TN, Giles County, TN, Lawrence County, TN, Lincoln County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Wayne County, TN

The radar

The Birmingham radar (KBMX), 71 km from the middle of the area, began a volume at 18:10 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Birmingham, AL (KBMX), launched 12:00Z, 6.2 hours before the alert went out and 70 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, Birmingham, AL at 12:00Z on 2009-04-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1268 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, Birmingham, AL at 12:00Z on 2009-04-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 177 square meters per square second.1939587897117136Sfc1 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
1268 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
463 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
177 m²/s²
0-3 km storm-relative helicity
192 m²/s²
Significant tornado parameter
1.2
Supercell composite
7.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 2, 3:12 AM CDTMesoscale DiscussionSPCChambers, Clay, Cleburne, Lee, Randolph, Tallapoosa63 min
Apr 2, 5:57 AM CDTMesoscale DiscussionSPCBaldwin, Barbour, Bullock, Butler, Coffee, Conecuh and 9 more63 min
Apr 2, 6:29 AM CDTTornado WatchSPCBaldwin, Barbour, Bullock, Butler, Choctaw, Clarke and 19 more8 hr
Apr 2, 10:06 AM CDTMesoscale DiscussionSPCDale, Geneva, Henry, Houston54 min
Apr 2, 1:33 PM CDTTornado WatchSPCAutauga, Baldwin, Bibb, Blount, Butler, Chilton and 36 more5 hr
Apr 2, 2:00 PM CDTTornado WatchSPCCoffee, Dale, Geneva, Henry, Houston7 hr
Apr 2, 3:42 PM CDTMesoscale DiscussionSPCAutauga, Bibb, Blount, Butler, Chilton, Coffee and 29 more63 min
Apr 2, 5:25 PM CDTMesoscale DiscussionSPCCalhoun, Cherokee, Cleburne, DeKalb95 min
Apr 2, 6:02 PM CDTTornado WatchSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 38 more7 hr
Apr 2, 8:01 AM CDTMesoscale DiscussionSPCAdams, Amite, Attala, Bolivar, Carroll, Claiborne and 32 more59 min
Apr 2, 9:24 AM CDTTornado WatchSPCAdams, Amite, Attala, Bolivar, Carroll, Choctaw and 49 more7 hr
Apr 2, 10:53 AM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, Coahoma, DeSoto and 16 more4 hr
Apr 2, 11:51 AM CDTMesoscale DiscussionSPCAmite, Attala, Carroll, Choctaw, Claiborne, Clarke and 40 more84 min
Apr 2, 3:36 PM CDTMesoscale DiscussionSPCAttala, Bolivar, Carroll, Claiborne, Coahoma, Copiah and 20 more54 min
Apr 2, 3:56 PM CDTSevere Thunderstorm WatchSPCAttala, Bolivar, Carroll, Choctaw, Clay, Coahoma and 21 more4 hr
Apr 2, 5:36 PM CDTMesoscale DiscussionSPCAlcorn, Attala, Benton, Calhoun, Carroll, Chickasaw and 25 more84 min
Apr 2, 6:21 PM CDTTornado WatchSPCAlcorn, Benton, Calhoun, Chickasaw, DeSoto, Itawamba and 9 more3 hr
Apr 2, 2:04 PM CDTMesoscale DiscussionSPCCheatham, Davidson, Houston, Macon, Montgomery, Robertson and 4 more116 min
Apr 2, 2:40 PM CDTTornado WatchSPCBenton, Cheatham, Davidson, DeKalb, Dickson, Houston and 9 more4 hr
Apr 2, 4:35 PM CDTMesoscale DiscussionSPCClay, Jackson, Pickett85 min

Nearby

Mesoscale Discussions in Alabama, 2009Mesoscale Discussions in Mississippi, 2009Mesoscale Discussions in Tennessee, 2009Every mesoscale discussion 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.