Alert archive / Tennessee / Mesoscale Discussions in 2003

Mesoscale Discussion 516

April 20, 20036 states

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2003, 1:00 PM CDT for 6 states. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 20, 2003, 1:00 PM CDT (18:00 UTC)
Expired
Apr 20, 2003, 3:30 PM CDT
In force
3 hr
Issued by
the Storm Prediction Center
All 84 counties

Crittenden County, AR, Lee County, AR, Mississippi County, AR, Gallatin County, IL, Hardin County, IL, Johnson County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Saline County, IL, Ballard County, KY, Breckinridge County, KY, Butler County, KY, Caldwell County, KY, Calloway County, KY, Carlisle County, KY, Christian County, KY, Crittenden County, KY, Daviess County, KY, Fulton County, KY, Graves County, KY, Grayson County, KY, Hancock County, KY, Henderson County, KY, Hickman County, KY, Hopkins County, KY, Livingston County, KY, Logan County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, McLean County, KY, Muhlenberg County, KY, Ohio County, KY, Simpson County, KY, Todd County, KY, Trigg County, KY, Union County, KY, Warren County, KY, Webster County, KY, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Alcorn County, MS, Benton County, MS, Coahoma County, MS, DeSoto County, MS, Marshall County, MS, Panola County, MS, Quitman County, MS, Tate County, MS, Tippah County, MS, Tunica County, MS, Benton County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Crockett County, TN, Davidson County, TN, Decatur County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Gibson County, TN, Hardeman County, TN, Hardin County, TN, Haywood County, TN, Henderson County, TN, Henry County, TN, Hickman County, TN, Houston County, TN, Humphreys County, TN, Lake County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Montgomery County, TN, Obion County, TN, Perry County, TN, Robertson County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Weakley County, TN

The watches that followed

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

The nearest sounding before it

Little Rock, AR (KLZK), launched 12:00Z, 6.0 hours before the alert went out and 142 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, Little Rock, AR at 12:00Z on 2003-04-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 339 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, Little Rock, AR at 12:00Z on 2003-04-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 128 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
339 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
777 m above ground
0-6 km bulk shear
40 kt
0-1 km storm-relative helicity
128 m²/s²
0-3 km storm-relative helicity
147 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.8

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, 7:54 PM CDTMesoscale DiscussionSPCPolk, Sebastian96 min
Apr 19, 8:55 PM CDTSevere Thunderstorm WatchSPCBenton, Crawford, Sebastian, Washington5 hr
Apr 19, 9:40 PM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Franklin, Johnson, Madison and 3 more65 min
Apr 19, 10:35 PM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Carroll, Franklin, Johnson, Madison and 5 more5 hr
Apr 19, 10:42 PM CDTMesoscale DiscussionSPCBenton, Crawford, Sebastian, Washington93 min
Apr 20, 1:25 AM CDTMesoscale DiscussionSPCBaxter, Boone, Clay, Cleburne, Craighead, Fulton and 13 more2 hr
Apr 20, 4:00 AM CDTMesoscale DiscussionSPCClay2 hr
Apr 20, 11:52 AM CDTMesoscale DiscussionSPCArkansas, Bradley, Cleveland, Craighead, Crittenden, Cross and 8 more2 hr
Apr 20, 3:02 PM CDTMesoscale DiscussionSPCAshley, Chicot, Desha, Drew3 hr
Apr 20, 1:50 AM CDTSevere Thunderstorm WatchSPCJackson, Monroe, Perry, Randolph, Washington5 hr
Apr 20, 12:20 PM CDTSevere Thunderstorm WatchSPCClark, Crawford, Edgar, Edwards, Hamilton, Jasper and 6 more6 hr
Apr 20, 1:45 PM CDTSevere Thunderstorm WatchSPCGallatin, Hardin, Johnson, Massac, Pope, Saline5 hr
Apr 20, 3:15 PM CDTSevere Thunderstorm WatchSPCBoone, Bracken, Campbell, Carroll, Gallatin, Grant and 8 more6 hr
Apr 20, 3:29 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bath, Bourbon and 43 more2 hr
Apr 20, 4:35 PM CDTTornado WatchSPCAdair, Allen, Anderson, Barren, Boyle, Breckinridge and 34 more5 hr
Apr 20, 5:31 PM CDTMesoscale DiscussionSPCBoone, Bracken, Campbell, Gallatin, Greenup, Kenton and 1 more89 min
Apr 20, 6:04 PM CDTMesoscale DiscussionSPCAdair, Anderson, Barren, Boyle, Breckinridge, Bullitt and 33 more116 min
Apr 20, 6:25 PM CDTSevere Thunderstorm WatchSPCAllen, Barren, Calloway, Christian, Graves, Logan and 5 more6 hr
Apr 19, 8:29 PM CDTMesoscale DiscussionSPCBarton, Bates, Benton, Camden, Cass, Cedar and 15 more2 hr

Nearby

Mesoscale Discussions in Tennessee, 2003Mesoscale Discussions in Kentucky, 2003Mesoscale Discussions in Mississippi, 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.