Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 683

May 2, 200320 counties in Alabama; 26 counties in Mississippi; 10 counties in Tennessee

The Storm Prediction Center issued this mesoscale discussion at May 2, 2003, 1:43 PM CDT for 20 counties in Alabama; 26 counties in Mississippi; 10 counties in Tennessee. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued: May 2, 2003, 1:43 PM CDT (18:43 UTC)
Expired: May 2, 2003, 3:15 PM CDT
In force: 92 min
Issued by: the Storm Prediction Center

All 56 counties

Blount County, AL, Colbert County, AL, Cullman County, AL, Etowah County, AL, Fayette County, AL, Franklin 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, St. Clair County, AL, Tuscaloosa County, AL, Walker County, AL, Winston County, AL, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, Clay County, MS, DeSoto County, MS, Grenada County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Lowndes County, MS, Marshall County, MS, Monroe County, MS, Oktibbeha County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Quitman County, MS, Tallahatchie County, MS, Tate County, MS, Tippah County, MS, Tishomingo County, MS, Tunica County, MS, Union County, MS, Webster County, MS, Yalobusha County, MS, Chester County, TN, Fayette County, TN, Giles County, TN, Hardeman County, TN, Hardin County, TN, Lawrence County, TN, Lincoln County, TN, McNairy County, TN, Shelby County, TN, Wayne 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, 6.7 hours before the alert went out and 154 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1636 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 710 m above ground
0-6 km bulk shear: 33 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 118 m²/s²
Significant tornado parameter: 0.6
Supercell composite: 3.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

650 
ACUS11 KWNS 021843
SWOMCD
SPC MCD 021843 
ALZ000-TNZ000-MSZ000-ARZ000-022015-

MESOSCALE DISCUSSION 0683
NWS STORM PREDICTION CENTER NORMAN OK
0143 PM CDT FRI MAY 02 2003

AREAS AFFECTED...SRN TN...NRN MS...AND NRN AL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 021843Z - 022015Z

SCATTERED THUNDERSTORMS ARE EXPECTED TO DEVELOP AND INTENSIFY ACROSS
NRN MS...NRN AL...AND SRN TN DURING THE NEXT FEW HOURS. THREAT OF
DAMAGING WIND AND LARGE HAIL ACCOMPANYING THESE CELLS WILL LIKELY
NECESSITATE A SEVERE THUNDERSTORM WATCH SOON. 

VISIBLE SATELLITE IMAGERY AT 1830Z INDICATES VIGOROUS CONVECTIVE
TOWERS 45 SW TUP AND 45 SE MKL. AN OVERALL INCREASING IN THE
LOW-LEVEL CUMULUS FIELD WAS ALSO NOTED ACROSS THE ENTIRE REGION.
WITH TEMPERATURES IN THE LOW 80S AND DEWPOINTS IN THE MID TO UPPER
60S...AIR MASS HAS BECOME VERY UNSTABLE WITH 100MB MLCAPE VALUES OF
2000-3000 J/KG. WLY DEEP LAYER SHEAR /0-6KM/ VALUES ON THE ORDER OF
30KT SHOULD BE SUPPORTIVE OF MULTICELLULAR STORMS WITH LARGE HAIL
AND DAMAGING DOWNDRAFT WINDS. SEVERAL CLUSTERS OF STORMS ARE LIKELY
LATER THIS AFTERNOON...WITH POTENTIAL FOR ORGANIZED LINES/BOW
SEGMENTS WITH POTENTIAL FOR WIND DAMAGE. 

..BANACOS.. 05/02/2003

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OHX...BMX...HUN...MEG...JAN...

35568830 35308651 34618593 34208590 33308649 33148740
33168819 33398941 33689001 34009032 34589048 35079036
35568954

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 2, 1:55 PM CDT	Severe Thunderstorm Watch	SPC	Blount, Calhoun, Cherokee, Clay, Cleburne, Colbert and 23 more	5 hr
May 2, 3:25 PM CDT	Severe Thunderstorm Watch	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 26 more	4 hr
May 2, 4:57 PM CDT	Mesoscale Discussion	SPC	Autauga, Barbour, Bibb, Bullock, Butler, Chambers and 25 more	93 min
May 2, 5:05 PM CDT	Tornado Watch	SPC	Autauga, Baldwin, Barbour, Bibb, Bullock, Butler and 37 more	5 hr
May 2, 5:36 PM CDT	Mesoscale Discussion	SPC	Blount, Calhoun, Cherokee, Clay, Cleburne, Colbert and 23 more	84 min
May 2, 2:21 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Bolivar, Carroll, Choctaw and 33 more	114 min
May 2, 2:55 PM CDT	Severe Thunderstorm Watch	SPC	Attala, Benton, Bolivar, Calhoun, Carroll, Choctaw and 21 more	6 hr
May 2, 6:31 PM CDT	Mesoscale Discussion	SPC	Attala, Benton, Bolivar, Calhoun, Carroll, Choctaw and 21 more	119 min
May 2, 8:52 AM CDT	Mesoscale Discussion	SPC	Anderson, Bledsoe, Campbell, Cannon, Cheatham, Clay and 23 more	113 min
May 2, 1:23 PM CDT	Mesoscale Discussion	SPC	Carter, Cocke, Greene, Hamblen, Hawkins, Jefferson and 4 more	2 hr
May 2, 1:35 PM CDT	Severe Thunderstorm Watch	SPC	Carter, Cocke, Greene, Hawkins, Johnson, Sullivan and 2 more	5 hr

Nearby

Mesoscale Discussions in Mississippi, 2003 Mesoscale Discussions in Alabama, 2003 Mesoscale Discussions in Tennessee, 2003 Every 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.