Alert archive / Tennessee / Mesoscale Discussions in 2003

Mesoscale Discussion 1944

July 21, 20035 states

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2003, 3:14 PM CDT for 5 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 21, 2003, 3:14 PM CDT (20:14 UTC)
Expired
Jul 21, 2003, 5:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 100 counties

Blount County, AL, Calhoun County, AL, Cherokee County, AL, Clay County, AL, Cleburne 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, Randolph County, AL, Shelby County, AL, St. Clair County, AL, Talladega County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Dade County, GA, Fannin County, GA, Floyd County, GA, Gilmer County, GA, Gordon County, GA, Haralson County, GA, Murray County, GA, Polk County, GA, Walker County, GA, Whitfield County, GA, Allen County, KY, Christian County, KY, Cumberland County, KY, Logan County, KY, Monroe County, KY, Muhlenberg County, KY, Simpson County, KY, Todd County, KY, Warren County, KY, Choctaw County, MS, Clay County, MS, Itawamba County, MS, Lowndes County, MS, Monroe County, MS, Oktibbeha County, MS, Bedford County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Cannon County, TN, Clay County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Jackson County, TN, Lawrence County, TN, Lincoln County, TN, Loudon County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Pickett County, TN, Polk County, TN, Putnam County, TN, Rhea County, TN, Roane County, TN, Robertson County, TN, Rutherford County, TN, Sequatchie County, TN, Smith County, TN, Sumner County, TN, Trousdale County, TN, Van Buren County, TN, Warren County, TN, White County, TN, Wilson County, TN

The radar

The Northeast Alabama radar (KHTX), 96 km from the middle of the area, began a volume at 20:14 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

Nashville Metro, TN (KBNA), launched 12:00Z, 8.2 hours before the alert went out and 126 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 2003-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1467 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 2003-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.1939Sfc1 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
1467 J/kg
Mixed-layer CIN
-175 J/kg
Mixed-layer LCL
1108 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
117 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
Jul 21, 1:10 PM CDTMesoscale DiscussionSPCBlount, Colbert, Cullman, DeKalb, Etowah, Franklin and 9 more95 min
Jul 21, 1:45 PM CDTSevere Thunderstorm WatchSPCBlount, Cherokee, Colbert, Cullman, DeKalb, Etowah and 13 more5 hr
Jul 21, 6:00 PM CDTSevere Thunderstorm WatchSPCAutauga, Bibb, Calhoun, Chambers, Chilton, Choctaw and 18 more5 hr
Jul 21, 5:03 AM CDTMesoscale DiscussionSPCBoone, Campbell, Carroll, Gallatin, Grant, Henry and 5 more117 min
Jul 21, 5:10 AM CDTSevere Thunderstorm WatchSPCBoone, Bracken, Campbell, Carroll, Gallatin, Grant and 2 more6 hr
Jul 21, 6:39 AM CDTMesoscale DiscussionSPCBoyd, Bracken, Carter, Fleming, Greenup, Harrison and 5 more96 min
Jul 21, 7:03 AM CDTMesoscale DiscussionSPCAllen, Anderson, Barren, Breckinridge, Bullitt, Butler and 31 more117 min
Jul 21, 7:40 AM CDTSevere Thunderstorm WatchSPCBath, Boyd, Carter, Elliott, Greenup, Lawrence and 3 more5 hr
Jul 21, 10:27 AM CDTMesoscale DiscussionSPCBoone, Breckinridge, Bullitt, Butler, Caldwell, Carroll and 33 more2 hr
Jul 21, 11:55 AM CDTSevere Thunderstorm WatchSPCAdair, Allen, Barren, Boyle, Butler, Caldwell and 34 more6 hr
Jul 21, 1:41 PM CDTMesoscale DiscussionSPCBell, Floyd, Harlan, Knott, Leslie, Letcher and 3 more64 min
Jul 21, 3:50 PM CDTSevere Thunderstorm WatchSPCAnderson, Bledsoe, Blount, Bradley, Campbell, Claiborne and 21 more4 hr

Nearby

Mesoscale Discussions in Tennessee, 2003Mesoscale Discussions in Alabama, 2003Mesoscale Discussions in Georgia, 2003Every mesoscale discussion in 2003

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.