Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 409

April 6, 200310 counties in Arkansas; East Carroll Parish, Madison Parish, West Carroll Parish, Louisiana; 18 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2003, 10:00 AM CDT for 10 counties in Arkansas; East Carroll Parish, Madison Parish, West Carroll Parish, Louisiana; 18 counties in Mississippi. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 6, 2003, 10:00 AM CDT (15:00 UTC)
Expired
Apr 6, 2003, 12:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 31 counties

Arkansas County, AR, Ashley County, AR, Chicot County, AR, Desha County, AR, Drew County, AR, Jefferson County, AR, Lee County, AR, Lincoln County, AR, Monroe County, AR, Phillips County, AR, East Carroll Parish, LA, Madison Parish, LA, West Carroll Parish, LA, Attala County, MS, Bolivar County, MS, Carroll County, MS, Coahoma County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Leflore County, MS, Madison County, MS, Quitman County, MS, Sharkey County, MS, Sunflower County, MS, Tallahatchie County, MS, Warren County, MS, Washington County, MS, Yazoo 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, 3.0 hours before the alert went out and 130 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, Jackson, MS at 12:00Z on 2003-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 758 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, Jackson, MS at 12:00Z on 2003-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 112 square meters per square second.1939587897117Sfc1 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
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.

164 
ACUS11 KWNS 061501
SWOMCD
SPC MCD 061500 
MSZ000-ARZ000-LAZ000-061700-

MESOSCALE DISCUSSION 0409
NWS STORM PREDICTION CENTER NORMAN OK
1000 AM CDT SUN APR 06 2003

AREAS AFFECTED...SERN AR/WRN MS/ FAR NERN LA

CONCERNING...SEVERE THUNDERSTORM WATCH 99...

VALID 061500Z - 061700Z

CONVECTION ASSOCIATED WITH WARM ADVECTION IN FAR SERN AR/NERN LA
WILL CONTINUE TO SPREAD NEWD INTO WCNTRL MS. ACTIVITY WILL HAVE
THE POTENTIAL FOR LARGE HAIL/DAMAGING WINDS WITH A LOCALIZED
ISOLATED TORNADO POTENTIAL NEAR THE WARM FRONT. WW MAY BE
REQUIRED NE OF THE CURRENT WATCH WITHIN THE NEXT COUPLE OF HOURS.



50 KNOT LOW-LEVEL JET OVER LA WILL CONTINUE STRONG WARM AIR
ADVECTION INTO THE LOWER MS VALLEY REGION THIS MORNING OVER A
WARM FRONT POSITIONED ACROSS NRN LA/CNTRL MS. CONVECTION WILL
CONTINUE TO FORM ALONG THE WARM FRONT...REMAINING ELEVATED AS
THEY MOVE NEWD OVER THE COOLER SURFACE AIR N OF THE FRONT. MLCAPE
OF 500 TO 1000 J/KG WAS PRESENT ALONG AND N OF THE FRONT. S OF
THE FRONT...MLCAPES WERE SLIGHTLY HIGHER. CELLS THAT DEVELOP S OF
THE BOUNDARY IN THE SLIGHTLY MORE UNSTABLE AIR AND INTERACT WITH
THE WARM FRONT AS THEY MOVE NE WILL HAVE AN ISOLATED TORNADO
POTENTIAL. OTHERWISE...0-6 KM SHEAR AROUND 50 KNOTS WILL RESULT
IN STRONG UPDRAFTS CAPABLE OF PRODUCING LARGE HAIL/DAMAGING
WINDS. WW MAY BE REQUIRED NE OF WATCH 99 WITHIN THE NEXT COUPLE
OF HOURS.

..BROYLES.. 04/06/2003

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

ATTN...WFO...MEG...JAN...LZK...

31949076 32339144 33779216 34469221 35009120 34599025
33838978 33008950 32368997

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 7:38 AM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Columbia, Lafayette and 3 more97 min
Apr 6, 7:50 AM CDTSevere Thunderstorm WatchSPCAshley, Bradley, Calhoun, Chicot, Columbia, Drew and 6 more5 hr
Apr 6, 8:56 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 21 more2 hr
Apr 6, 9:45 AM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Conway, Crawford and 22 more5 hr
Apr 6, 10:20 AM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 21 more55 min
Apr 6, 10:30 AM CDTTornado WatchSPCAshley, Bradley, Calhoun, Chicot, Columbia, Drew and 6 more6 hr
Apr 6, 11:05 AM CDTSevere Thunderstorm WatchSPCArkansas, Baxter, Cleburne, Cleveland, Craighead, Crittenden and 27 more5 hr
Apr 6, 12:27 PM CDTMesoscale DiscussionSPCArkansas, Clark, Cleburne, Cleveland, Conway, Craighead and 46 more2 hr
Apr 6, 2:18 PM CDTMesoscale DiscussionSPCBoone, Conway, Crawford, Franklin, Garland, Howard and 16 more57 min
Apr 6, 2:55 PM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Clark, Cleburne, Conway, Crawford and 35 more5 hr
Apr 6, 3:45 PM CDTTornado WatchSPCAshley, Chicot, Union5 hr
Apr 6, 5:35 PM CDTMesoscale DiscussionSPCAshley, Chicot, Union115 min
Apr 6, 6:23 PM CDTMesoscale DiscussionSPCAshley, Chicot, Union97 min
Apr 6, 12:03 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 14 more117 min
Apr 6, 3:26 PM CDTMesoscale DiscussionSPCBienville, Caldwell, De Soto, Franklin, Grant, Jackson and 11 more2 hr
Apr 6, 6:50 PM CDTTornado WatchSPCAvoyelles, Caldwell, Catahoula, Concordia, East Carroll, Evangeline and 11 more6 hr
Apr 6, 12:40 PM CDTMesoscale DiscussionSPCAttala, Choctaw, Holmes, Kemper, Lauderdale, Leake and 9 more2 hr
Apr 6, 1:35 PM CDTTornado WatchSPCChoctaw, Clarke, Jasper, Jones, Kemper, Lauderdale and 7 more5 hr
Apr 6, 2:56 PM CDTMesoscale DiscussionSPCKemper, Lauderdale, Leake, Neshoba, Newton, Noxubee and 2 more2 hr

Nearby

Mesoscale Discussions in Mississippi, 2003Mesoscale Discussions in Arkansas, 2003Mesoscale Discussions in Louisiana, 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.