Alert archive / Mississippi / Mesoscale Discussions in 2006

Mesoscale Discussion 583

April 20, 20064 states

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2006, 1:38 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 20, 2006, 1:38 PM CDT (18:38 UTC)
Expired
Apr 20, 2006, 3:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 80 counties

Bibb County, AL, Blount County, AL, Calhoun County, AL, Cherokee County, AL, Clay County, AL, Colbert County, AL, Cullman County, AL, DeKalb County, AL, Etowah County, AL, Fayette County, AL, Franklin County, AL, Jackson County, AL, Jefferson County, AL, Lamar County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Marion County, AL, Marshall County, AL, Morgan County, AL, Pickens County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Walker County, GA, Alcorn County, MS, Attala County, MS, Bolivar County, MS, Calhoun County, MS, Carroll County, MS, Chickasaw County, MS, Choctaw County, MS, Clay County, MS, Grenada County, MS, Holmes County, MS, Humphreys County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Leflore County, MS, Lowndes County, MS, Monroe County, MS, Montgomery County, MS, Noxubee County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Sunflower County, MS, Tallahatchie County, MS, Tippah County, MS, Tishomingo County, MS, Union County, MS, Washington County, MS, Webster County, MS, Winston County, MS, Yalobusha County, MS, Bedford County, TN, Bledsoe County, TN, Coffee County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, Moore County, TN, Sequatchie County, TN

The radar

The Columbus AFB radar (KGWX), 49 km from the middle of the area, began a volume at 18:39 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, 6.6 hours before the alert went out and 168 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 2006-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 488 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 2006-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -119 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
488 J/kg
Mixed-layer CIN
-279 J/kg
Mixed-layer LCL
1148 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
-119 m²/s²
0-3 km storm-relative helicity
-98 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

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 19, 7:51 PM CDTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Bullock, Butler, Chilton and 20 more84 min
Apr 20, 11:19 AM CDTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 24 more86 min
Apr 20, 11:38 AM CDTSevere Thunderstorm WatchSPCBlount, Calhoun, Cherokee, Colbert, Cullman, DeKalb and 20 more7 hr
Apr 20, 3:40 PM CDTMesoscale DiscussionSPCBibb, Blount, Calhoun, Cherokee, Clay, Cleburne and 25 more2 hr
Apr 20, 3:55 PM CDTSevere Thunderstorm WatchSPCChambers, Clay, Cleburne, Coosa, Randolph, Tallapoosa6 hr
Apr 20, 6:11 PM CDTMesoscale DiscussionSPCBlount, Calhoun, Cherokee, Clay, Cleburne, Colbert and 19 more2 hr
Apr 20, 6:57 PM CDTSevere Thunderstorm WatchSPCBibb, Blount, Calhoun, Cherokee, Chilton, Colbert and 22 more5 hr
Apr 20, 1:53 PM CDTMesoscale DiscussionSPCBanks, Dawson, Fannin, Forsyth, Franklin, Gilmer and 9 more2 hr
Apr 20, 2:15 PM CDTSevere Thunderstorm WatchSPCAlcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 35 more7 hr
Apr 20, 4:15 PM CDTMesoscale DiscussionSPCAlcorn, Attala, Benton, Bolivar, Calhoun, Carroll and 33 more2 hr
Apr 20, 4:22 AM CDTMesoscale DiscussionSPCBenton, Carroll, Cheatham, Chester, Crockett, Davidson and 27 more113 min
Apr 20, 11:24 AM CDTMesoscale DiscussionSPCAnderson, Blount, Campbell, Carter, Claiborne, Cocke and 19 more2 hr

Nearby

Mesoscale Discussions in Mississippi, 2006Mesoscale Discussions in Alabama, 2006Mesoscale Discussions in Tennessee, 2006Every mesoscale discussion in 2006

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.