Alert archive / Tennessee / Mesoscale Discussions in 2009

Mesoscale Discussion 758

May 8, 20097 states

The Storm Prediction Center issued this mesoscale discussion at May 8, 2009, 8:37 AM CDT for 7 states. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
May 8, 2009, 8:37 AM CDT (13:37 UTC)
Expired
May 8, 2009, 9:30 AM CDT
In force
53 min
Issued by
the Storm Prediction Center
All 111 counties

Colbert County, AL, Jackson County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Faulkner County, AR, Greene County, AR, Independence County, AR, Jackson County, AR, Lawrence County, AR, Lee County, AR, Mississippi County, AR, Monroe County, AR, Poinsett County, AR, Prairie County, AR, Randolph County, AR, St. Francis County, AR, White County, AR, Woodruff County, AR, Alexander County, IL, Massac County, IL, Pulaski County, IL, Ballard County, KY, Calloway County, KY, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Lyon County, KY, Marshall County, KY, McCracken County, KY, Trigg County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Dunklin County, MO, Madison County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Wayne County, MO, Alcorn County, MS, Benton County, MS, DeSoto County, MS, Marshall County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Bedford County, TN, Benton County, TN, Cannon County, TN, Carroll County, TN, Cheatham County, TN, Chester County, TN, Coffee County, TN, Crockett County, TN, Davidson County, TN, Decatur County, TN, DeKalb County, TN, Dickson County, TN, Dyer County, TN, Fayette County, TN, Franklin County, TN, Gibson County, TN, Giles County, TN, Grundy 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, Lawrence County, TN, Lewis County, TN, Lincoln County, TN, Madison County, TN, Marion County, TN, Marshall County, TN, Maury County, TN, McNairy County, TN, Montgomery County, TN, Moore County, TN, Obion County, TN, Perry County, TN, Robertson County, TN, Rutherford County, TN, Sequatchie County, TN, Shelby County, TN, Stewart County, TN, Tipton County, TN, Van Buren County, TN, Warren County, TN, Wayne County, TN, Weakley County, TN, Williamson County, TN, Wilson County, TN

The radar

The Memphis radar (KNQA), 135 km from the middle of the area, began a volume at 13:41 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

Little Rock, AR (KLZK), launched 12:00Z, 1.6 hours before the alert went out and 173 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 2009-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1297 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 2009-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 144 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
1297 J/kg
Mixed-layer CIN
-163 J/kg
Mixed-layer LCL
606 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
144 m²/s²
0-3 km storm-relative helicity
138 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.1

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
May 8, 4:31 AM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Crawford, Franklin, Johnson and 3 more59 min
May 8, 4:55 AM CDTSevere Thunderstorm Watch PDSSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 10 more7 hr
May 8, 7:17 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Fulton, Izard and 1 more58 min
May 8, 9:21 AM CDTTornado WatchSPCClay, Cleburne, Craighead, Greene, Independence, Izard and 10 more7 hr
May 8, 11:08 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Crawford, Franklin, Fulton and 6 more67 min
May 8, 2:16 PM CDTMesoscale DiscussionSPCClay, Craighead, Greene, Lawrence, Mississippi, Poinsett and 2 more89 min
May 8, 3:24 PM CDTMesoscale DiscussionSPCGreene, Mississippi66 min
May 8, 3:42 PM CDTTornado WatchSPCClay, Craighead, Greene, Mississippi, Poinsett7 hr
May 8, 5:52 PM CDTTornado WatchSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 35 more11 hr
May 7, 9:38 PM CDTMesoscale DiscussionSPCClinton, Franklin, Gallatin, Hamilton, Jackson, Jefferson and 13 more97 min
May 7, 10:17 PM CDTSevere Thunderstorm WatchSPCAlexander, Franklin, Gallatin, Hardin, Jackson, Johnson and 9 more8 hr
May 7, 11:46 PM CDTMesoscale DiscussionSPCAlexander, Bond, Clark, Clay, Clinton, Coles and 33 more89 min
May 8, 3:34 AM CDTMesoscale DiscussionSPCAlexander, Massac, Pulaski56 min
May 8, 5:47 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Henderson, Henry, Jo Daviess and 9 more58 min
May 8, 6:10 PM CDTSevere Thunderstorm WatchSPCBureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 13 more4 hr
May 8, 4:29 AM CDTSevere Thunderstorm WatchSPCAdair, Allen, Barren, Clinton, Cumberland, Logan and 5 more3 hr
May 8, 12:08 PM CDTMesoscale DiscussionSPCAdair, Allen, Anderson, Barren, Bell, Bourbon and 54 more97 min
May 8, 12:44 PM CDTSevere Thunderstorm WatchSPCAdair, Allen, Anderson, Barren, Bath, Bell and 72 more6 hr
May 8, 5:03 PM CDTMesoscale DiscussionSPCBell, Boyd, Breathitt, Carter, Clay, Elliott and 20 more87 min
May 7, 7:37 PM CDTSevere Thunderstorm WatchSPCAdair, Andrew, Atchison, Buchanan, Caldwell, Carroll and 25 more6 hr
May 8, 5:32 PM CDTTornado WatchSPCCarter, Cocke, Greene, Hawkins, Johnson, Sullivan and 2 more7 hr

Nearby

Mesoscale Discussions in Tennessee, 2009Mesoscale Discussions in Arkansas, 2009Mesoscale Discussions in Missouri, 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.