Alert archive / Mississippi / Mesoscale Discussions in 2005

Mesoscale Discussion 511

April 6, 20054 states

The Storm Prediction Center issued this mesoscale discussion at Apr 6, 2005, 6:01 PM CDT for 4 states. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Apr 6, 2005, 6:01 PM CDT (23:01 UTC)
Expired
Apr 6, 2005, 7:00 PM CDT
In force
59 min
Issued by
the Storm Prediction Center
All 85 counties

Autauga County, AL, Baldwin County, AL, Bullock County, AL, Butler County, AL, Choctaw County, AL, Clarke County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dallas County, AL, Elmore County, AL, Escambia County, AL, Geneva County, AL, Hale County, AL, Lee County, AL, Lowndes County, AL, Macon County, AL, Marengo County, AL, Mobile County, AL, Monroe County, AL, Montgomery County, AL, Perry County, AL, Pike County, AL, Sumter County, AL, Washington County, AL, Wilcox County, AL, Escambia County, FL, Okaloosa County, FL, Santa Rosa County, FL, Walton County, FL, Orleans Parish, LA, Saint Bernard Parish, LA, Saint Tammany Parish, LA, Washington Parish, LA, Attala County, MS, Bolivar County, MS, Carroll County, MS, Choctaw County, MS, Clarke County, MS, Clay County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, George County, MS, Greene County, MS, Grenada County, MS, Hancock County, MS, Harrison County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jackson County, MS, Jasper County, MS, Jefferson Davis County, MS, Jones County, MS, Kemper County, MS, Lamar County, MS, Lauderdale County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lowndes County, MS, Madison County, MS, Marion County, MS, Montgomery County, MS, Neshoba County, MS, Newton County, MS, Noxubee County, MS, Oktibbeha County, MS, Pearl River County, MS, Perry County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Smith County, MS, Stone County, MS, Sunflower County, MS, Washington County, MS, Wayne County, MS, Webster County, MS, Winston County, MS, Yazoo County, MS

The radar

The Mobile radar (KMOB), 109 km from the middle of the area, began a volume at 23:03 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

Jackson, MS (KJAN), launched 12:00Z, 11.0 hours before the alert went out and 145 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 2005-04-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 268 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 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 2005-04-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 278 square meters per square second.1939587897Sfc1 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
268 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
618 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
278 m²/s²
0-3 km storm-relative helicity
332 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.7

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 062301
SWOMCD
SPC MCD 062301 
ALZ000-FLZ000-MSZ000-LAZ000-ARZ000-070000-

MESOSCALE DISCUSSION 0511
NWS STORM PREDICTION CENTER NORMAN OK
0601 PM CDT WED APR 06 2005

AREAS AFFECTED...SERN LA...CENTRAL/SRN MS...CENTRAL/SRN AL...AND THE
WRN FL PANHANDLE

CONCERNING...TORNADO WATCH 131...132...

VALID 062301Z - 070000Z

THREAT OF TORNADIC SUPERCELLS CONTINUES ACROSS ERN MS EWD INTO AL. 
A NEW TORNADO WATCH WILL LIKELY BE REQUIRED BEFORE 07/00Z FOR
PORTIONS OF FAR ERN MS AND AL...TO REPLACE WW 131 AND 132.  

AT 2245Z...DRY SLOT ASSOCIATED WITH VERTICALLY STACKED CYCLONE
EXTENDS FROM S-CENTRAL LA NNEWD ALONG MS RIVER VALLEY ACROSS ERN
AR/WRN MS. SURFACE COLD FRONT CONTINUES EWD ACROSS WRN MS WITH
PRIMARY MOISTURE/INSTABILITY AXIS EAST OF THE FRONT ACROSS CENTRAL
MS. SURFACE DEWPOINTS IN THE MID 60S ARE CONTRIBUTING TO MLCAPE
VALUES OF 1000-1500 J/KG ACROSS CENTRAL/ERN MS...WHERE SCATTERED SVR
CONVECTION CONTINUES. CYCLONIC UPPER JET ACROSS THE AREA AND 0-6KM
SHEAR IN EXCESS OF 50KT WILL MAINTAIN THREAT OF SUPERCELLS WITH
LARGE HAIL AND DAMAGING WINDS. STRONG LOW-LEVEL VEERING/HODOGRAPH
CURVATURE WILL MAINTAIN THREAT OF TORNADIC ACTIVITY ESPECIALLY
WITHIN NARROW WARM SECTOR IN ERN MS/WRN AL DURING NEXT 1-3 HOURS.
DRYING FROM THE WEST SHOULD END THREAT OF SEVERE WEATHER ACROSS SRN
MS AND SERN LA DURING NEXT COUPLE OF HOURS. 

FURTHER EAST...LEADING MCS HAS WEAKENED IN RESPONSE TO LIMITED
LOW-LEVEL MOISTURE ACROSS ERN AL AND THE WRN FL PANHANDLE.
HOWEVER...SOME AIR MASS RECOVERY IS LIKELY FROM THE WEST AS PRIMARY
MOISTURE/INSTABILITY AXIS SHIFTS EWD. THIS SUGGESTS THAT A NEW
TORNADO WATCH WILL LIKELY BE NEEDED FOR PORTIONS OF THE WW 131 AND
WW 132 AREAS AS UPSTREAM SUPERCELLS TRACK FROM CENTRAL MS 
GENERALLY ENEWD INTO W-CENTRAL AL. ADDITIONAL CONVECTIVE LINE SOUTH
OF MOBILE BAY WILL ALSO BE MONITORED AS IT TRACKS TOWARD THE FL
PANHANDLE. HOWEVER...UPPER FLOW IS LARGELY PARALLEL TO CONVECTIVE
LINE AND THIS SHOULD LIMIT POTENTIAL FOR BOWING SEGMENTS AND ANY
WIDESPREAD WIND DAMAGE.

..BANACOS.. 04/06/2005

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

ATTN...WFO...TAE...BMX...MOB...MEG...JAN...LIX...LZK...

29468956 29499002 31189010 32059062 33079128 33899105
33898826 32798840 32738517 30348602 29338688

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 7:00 AM CDTTornado WatchSPCChoctaw, Greene, Mobile, Pickens, Sumter, Washington6 hr
Apr 6, 9:29 AM CDTMesoscale DiscussionSPCChoctaw, Greene, Mobile, Pickens, Sumter, Washington2 hr
Apr 6, 10:50 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 9 more55 min
Apr 6, 11:05 AM CDTTornado WatchSPCAutauga, Baldwin, Bullock, Butler, Choctaw, Clarke and 20 more8 hr
Apr 6, 1:21 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bullock, Butler, Choctaw, Clarke and 20 more84 min
Apr 6, 3:43 PM CDTMesoscale DiscussionSPCAutauga, Baldwin, Bullock, Butler, Choctaw, Clarke and 20 more92 min
Apr 6, 4:53 PM CDTMesoscale DiscussionSPCBibb, Blount, Chilton, Colbert, Coosa, Cullman and 19 more37 min
Apr 6, 5:20 PM CDTTornado WatchSPCBibb, Chilton, Cullman, Fayette, Greene, Hale and 8 more8 hr
Apr 6, 6:45 PM CDTTornado WatchSPCAutauga, Bibb, Butler, Chilton, Choctaw, Clarke and 20 more6 hr
Apr 5, 8:25 PM CDTSevere Thunderstorm WatchSPCBossier, Caddo8 hr
Apr 5, 10:40 PM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 50 more2 hr
Apr 6, 2:55 AM CDTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 36 more7 hr
Apr 6, 5:45 AM CDTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 36 more90 min
Apr 6, 7:46 AM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 20 more119 min
Apr 6, 10:40 AM CDTMesoscale DiscussionSPCCaldwell, Catahoula, East Carroll, Franklin, Grant, Jackson and 11 more65 min
Apr 6, 11:05 AM CDTTornado WatchSPCAscension, Assumption, Concordia, East Baton Rouge, East Carroll, East Feliciana and 22 more8 hr
Apr 6, 1:55 PM CDTTornado WatchSPCBenton, Calhoun, Chickasaw, Coahoma, DeSoto, Lafayette and 12 more7 hr
Apr 6, 3:18 PM CDTMesoscale DiscussionSPCBenton, Calhoun, Chickasaw, Coahoma, DeSoto, Lafayette and 12 more87 min
Apr 6, 5:44 PM CDTMesoscale DiscussionSPCBenton, Calhoun, Chickasaw, Coahoma, DeSoto, Lafayette and 12 more91 min

Nearby

Mesoscale Discussions in Mississippi, 2005Mesoscale Discussions in Alabama, 2005Mesoscale Discussions in Florida, 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.