Alert archive / Alabama / Mesoscale Discussions in 2009

Mesoscale Discussion 463

April 13, 200916 counties in Alabama; 5 counties in Florida; 4 counties in Georgia

The Storm Prediction Center issued this mesoscale discussion at Apr 13, 2009, 4:32 AM CDT for 16 counties in Alabama; 5 counties in Florida; 4 counties in Georgia. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued
Apr 13, 2009, 4:32 AM CDT (09:32 UTC)
Expired
Apr 13, 2009, 5:30 AM CDT
In force
58 min
Issued by
the Storm Prediction Center
All 25 counties

Baldwin County, AL, Barbour County, AL, Bullock County, AL, Butler 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, Mobile County, AL, Pike County, AL, Russell County, AL, Escambia County, FL, Holmes County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Chattahoochee County, GA, Clay County, GA, Quitman County, GA, Stewart County, GA

The radar

The Eglin Afb radar (KEVX), 98 km from the middle of the area, began a volume at 09:32 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

Birmingham, AL (KBMX), launched 00:00Z, 9.5 hours before the alert went out and 219 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 00:00Z on 2009-04-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2009-04-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 140 square meters per square second.19395878Sfc1 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
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

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, 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

Nearby

Mesoscale Discussions in Alabama, 2009Mesoscale Discussions in Florida, 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.