Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 472

April 13, 20094 states

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2009, 5:52 PM CDT for 4 states. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Apr 13, 2009, 5:52 PM CDT (22:52 UTC)
Expired
Apr 13, 2009, 6:45 PM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 34 counties

Blount County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Walker County, GA, Whitfield County, GA, Lowndes County, MS, Noxubee County, MS, Bledsoe County, TN, Bradley County, TN, Franklin County, TN, Grundy County, TN, Hamilton County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Polk County, TN, Rhea County, TN, Sequatchie County, TN

The radar

The Northeast Alabama radar (KHTX), 55 km from the middle of the area, began a volume at 22:51 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 nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 10.9 hours before the alert went out and 187 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, Nashville Metro, TN at 12:00Z on 2009-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 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, Nashville Metro, TN at 12:00Z on 2009-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 366 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
730 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
366 m²/s²
0-3 km storm-relative helicity
512 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 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, 2:33 AM CDTTornado WatchSPCBaldwin, Barbour, Bullock, Butler, Clarke, Coffee and 14 more7 hr
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, 6:55 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Clarke, Dallas, Greene and 9 more95 min
Apr 13, 11:32 AM CDTTornado WatchSPCAppling, Atkinson, Bacon, Brantley, Bryan, Camden and 19 more6 hr
Apr 13, 5:53 PM CDTTornado WatchSPCBrooks, Camden, Charlton, Clinch, Echols, Lanier and 2 more5 hr
Apr 13, 1:39 PM CDTMesoscale DiscussionSPCAdams, Amite, Copiah, Covington, Forrest, Franklin and 14 more66 min
Apr 13, 3:22 PM CDTMesoscale DiscussionSPCBedford, Cannon, Clay, Coffee, DeKalb, Giles and 10 more53 min

Nearby

Mesoscale Discussions in Alabama, 2009Mesoscale Discussions in Tennessee, 2009Mesoscale Discussions in Georgia, 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.