Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 413

April 6, 20037 counties in Alabama; 15 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2003, 12:40 PM CDT for 7 counties in Alabama; 15 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Apr 6, 2003, 12:40 PM CDT (17:40 UTC)
Expired: Apr 6, 2003, 2:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 22 counties

Greene County, AL, Hale County, AL, Marengo County, AL, Perry County, AL, Pickens County, AL, Sumter County, AL, Tuscaloosa County, AL, Attala County, MS, Choctaw County, MS, Holmes County, MS, Kemper County, MS, Lauderdale County, MS, Leake County, MS, Lowndes County, MS, Madison County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Rankin County, MS, Scott County, MS, Winston County, MS

The watches that followed

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

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 5.7 hours before the alert went out and 116 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: 758 J/kg
Mixed-layer CIN: -54 J/kg
Mixed-layer LCL: 544 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 168 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.1

Open this sounding in Storm Lab

The text

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

120 
ACUS11 KWNS 061741
SWOMCD
SPC MCD 061740 
ALZ000-MSZ000-061945-

MESOSCALE DISCUSSION 0413
NWS STORM PREDICTION CENTER NORMAN OK
1240 PM CDT SUN APR 06 2003

AREAS AFFECTED...CNTRL MS/WRN AL

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 061740Z - 061945Z

SHORT SQUALL-LINE SEGMENT WITH EMBEDDED SUPERCELLS ACROSS NRN
LA/WCNTRL MS WILL CONTINUE MOVING EWD ACROSS CNTRL MS AND INTO
WCNTRL AL. A TORNADO WATCH MAY BE NEEDED E OF THE CURRENT WATCH
IN THE NEXT FEW HOURS.



WARM FRONT EXTENDING W TO E ACROSS CNTRL MS/CNTRL LA WILL BE THE
FOCUS FOR SEVERE STORM DEVELOPMENT THIS AFTERNOON. DEWPOINTS IN
THE MID TO UPPER 60S HAVE RESULTING IN SBCAPES OF 1000-2000 J/KG
IN THE VICINITY OF THE WARM FRONT ACROSS CNTRL MS. ACTIVITY IS
CURRENTLY WELL E OF THE LOW-LEVEL JET. HOWEVER...CYCLOGENESIS
CURRENTLY DEVELOPING OVER CNTRL MS MAY RESULT IN THE DEVELOPMENT
OF A SMALLER MESOSCALE LOW-LEVEL JET FURTHER TO THE E. THIS WOULD
INCREASE DEEP LAYER SHEAR ENOUGH FOR SUPERCELLS OR BOW ECHOES TO
BE SUSTAINED AS AS THEY CONTINUE TO TRACK EWD AT 40-45 MPH LATER
THIS AFTERNOON. ISOLATED TORNADOES...DAMAGING WINDS AND LARGE
HAIL WILL BE POSSIBLE WITH THE SUPERCELLS.

..BROYLES.. 04/06/2003

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

ATTN...WFO...BMX...MOB...JAN...

32879037 33258999 33488882 33548798 33418727 32618704
32128789 32048996 32229041

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 6, 9:19 AM CDT	Mesoscale Discussion	SPC	Limestone, Madison	116 min
Apr 6, 1:20 PM CDT	Severe Thunderstorm Watch	SPC	Lauderdale	6 hr
Apr 6, 1:35 PM CDT	Tornado Watch	SPC	Bibb, Butler, Chilton, Choctaw, Clarke, Dallas and 8 more	5 hr
Apr 6, 2:56 PM CDT	Mesoscale Discussion	SPC	Bibb, Chilton, Dallas, Greene, Hale, Perry and 4 more	2 hr
Apr 6, 6:23 PM CDT	Mesoscale Discussion	SPC	Bibb, Blount, Choctaw, Cullman, Fayette, Franklin and 14 more	97 min
Apr 6, 6:50 PM CDT	Tornado Watch	SPC	Autauga, Bibb, Chilton, Choctaw, Cullman, Dallas and 12 more	6 hr
Apr 6, 7:38 AM CDT	Mesoscale Discussion	SPC	Adams, Claiborne, Copiah, Franklin, Hinds, Issaquena and 5 more	97 min
Apr 6, 7:50 AM CDT	Severe Thunderstorm Watch	SPC	Bolivar, Hinds, Holmes, Humphreys, Issaquena, Leflore and 5 more	5 hr
Apr 6, 10:00 AM CDT	Mesoscale Discussion	SPC	Attala, Bolivar, Carroll, Coahoma, Grenada, Hinds and 12 more	2 hr
Apr 6, 10:20 AM CDT	Mesoscale Discussion	SPC	Attala, Bolivar, Calhoun, Carroll, Chickasaw, Choctaw and 36 more	55 min
Apr 6, 10:30 AM CDT	Tornado Watch	SPC	Adams, Attala, Carroll, Claiborne, Copiah, Covington and 23 more	6 hr
Apr 6, 11:05 AM CDT	Severe Thunderstorm Watch	SPC	Alcorn, Benton, Bolivar, Calhoun, Chickasaw, Coahoma and 15 more	5 hr
Apr 6, 12:03 PM CDT	Mesoscale Discussion	SPC	Claiborne, Issaquena, Warren	117 min
Apr 6, 12:27 PM CDT	Mesoscale Discussion	SPC	Benton, Coahoma, DeSoto, Lafayette, Marshall, Panola and 8 more	2 hr
Apr 6, 3:45 PM CDT	Tornado Watch	SPC	Adams, Amite, Attala, Carroll, Claiborne, Copiah and 23 more	5 hr
Apr 6, 5:35 PM CDT	Mesoscale Discussion	SPC	Adams, Amite, Attala, Carroll, Claiborne, Copiah and 25 more	115 min

Nearby

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