Alert archive / Tennessee / Mesoscale Discussions in 2005

Mesoscale Discussion 928

May 20, 20055 states

The Storm Prediction Center issued this mesoscale discussion at May 20, 2005, 7:42 AM CDT for 5 states. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
May 20, 2005, 7:42 AM CDT (12:42 UTC)
Expired
May 20, 2005, 9:15 AM CDT
In force
93 min
Issued by
the Storm Prediction Center
All 113 counties

DeKalb County, AL, Jackson County, AL, Limestone County, AL, Madison County, AL, Banks County, GA, Barrow County, GA, Bartow County, GA, Catoosa County, GA, Chattooga County, GA, Cherokee County, GA, Clarke County, GA, Cobb County, GA, Dade County, GA, Dawson County, GA, DeKalb County, GA, Elbert County, GA, Fannin County, GA, Floyd County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Gilmer County, GA, Gordon County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Hart County, GA, Jackson County, GA, Lumpkin County, GA, Madison County, GA, Morgan County, GA, Murray County, GA, Newton County, GA, Oconee County, GA, Paulding County, GA, Pickens County, GA, Polk County, GA, Rabun County, GA, Rockdale County, GA, Stephens County, GA, Towns County, GA, Union County, GA, Walker County, GA, Walton County, GA, White County, GA, Whitfield County, GA, Cherokee County, NC, Clay County, NC, Graham County, NC, Macon County, NC, Abbeville County, SC, Anderson County, SC, Chester County, SC, Chesterfield County, SC, Fairfield County, SC, Greenwood County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Newberry County, SC, Oconee County, SC, Richland County, SC, Saluda County, SC, Union County, SC, Bedford County, TN, Bledsoe County, TN, Bradley County, TN, Cannon County, TN, Cheatham County, TN, Coffee County, TN, Cumberland County, TN, Davidson County, TN, DeKalb County, TN, Dickson County, TN, Fentress County, TN, Franklin County, TN, Giles County, TN, Grundy County, TN, Hamilton County, TN, Hickman County, TN, Humphreys County, TN, Jackson County, TN, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Loudon County, TN, Macon County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Montgomery County, TN, Moore County, TN, Morgan County, TN, Overton County, TN, Perry 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, Williamson County, TN, Wilson County, TN

The radar

The Knoxville radar (KMRX), 153 km from the middle of the area, began a volume at 12:43 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 0.7 hours before the alert went out and 177 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, Peachtre/Fal Fld, GA at 12:00Z on 2005-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 580 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, Peachtre/Fal Fld, GA at 12:00Z on 2005-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
580 J/kg
Mixed-layer CIN
-82 J/kg
Mixed-layer LCL
1118 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
52 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

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
May 20, 4:18 AM CDTMesoscale DiscussionSPCJackson57 min
May 20, 8:40 AM CDTSevere Thunderstorm WatchSPCBlount, Calhoun, Chambers, Cherokee, Clay, Cleburne and 24 more7 hr
May 20, 12:55 PM CDTMesoscale DiscussionSPCAutauga, Barbour, Bibb, Blount, Bullock, Butler and 52 more65 min
May 20, 3:10 PM CDTSevere Thunderstorm WatchSPCAutauga, Barbour, Bibb, Bullock, Butler, Chambers and 36 more8 hr
May 20, 6:44 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Barbour, Bibb, Bullock, Butler and 40 more91 min
May 20, 1:00 AM CDTSevere Thunderstorm WatchSPCHart7 hr
May 20, 1:30 AM CDTSevere Thunderstorm WatchSPCBanks, Barrow, Catoosa, Cherokee, Dade, Dawson and 20 more8 hr
May 20, 4:52 AM CDTMesoscale DiscussionSPCBaldwin, Bleckley, Burke, Candler, Columbia, Emanuel and 18 more53 min
May 20, 12:16 PM CDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Effingham and 11 more29 min
May 20, 12:20 PM CDTSevere Thunderstorm WatchSPCAppling, Bacon, Bryan, Bulloch, Burke, Candler and 15 more7 hr
May 20, 1:43 PM CDTMesoscale DiscussionSPCAppling, Bacon, Bryan, Bulloch, Burke, Candler and 14 more62 min
May 20, 3:40 PM CDTMesoscale DiscussionSPCAppling, Bacon, Bryan, Bulloch, Candler, Chatham and 10 more95 min
May 19, 11:56 PM CDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Buncombe and 39 more2 hr
May 19, 11:58 PM CDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Buncombe and 39 more2 hr
May 20, 2:45 PM CDTMesoscale DiscussionSPCCherokee, Clay, Graham, Macon, Swain60 min
May 19, 8:31 PM CDTMesoscale DiscussionSPCClaiborne, Clay, Fentress, Hancock, Jackson, Macon and 7 more89 min
May 19, 8:50 PM CDTSevere Thunderstorm WatchSPCCheatham, Davidson, Dickson, Henry, Houston, Montgomery and 3 more5 hr
May 19, 9:05 PM CDTSevere Thunderstorm WatchSPCAnderson, Campbell, Carter, Claiborne, Clay, Davidson and 21 more5 hr

Nearby

Mesoscale Discussions in Tennessee, 2005Mesoscale Discussions in Georgia, 2005Mesoscale Discussions in South Carolina, 2005Every mesoscale discussion in 2005

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.