Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 1958

July 22, 200321 parishes in Louisiana; 24 counties in Mississippi; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Jul 22, 2003, 1:42 PM CDT for 21 parishes in Louisiana; 24 counties in Mississippi; 12 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 22, 2003, 1:42 PM CDT (18:42 UTC)
Expired
Jul 22, 2003, 3:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 57 counties

Avoyelles Parish, LA, Bienville Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Saint Helena Parish, LA, Tensas Parish, LA, Vernon Parish, LA, Washington Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Jefferson County, MS, Jefferson Davis County, MS, Jones County, MS, Lamar County, MS, Lawrence County, MS, Lincoln County, MS, Marion County, MS, Pearl River County, MS, Perry County, MS, Pike County, MS, Simpson County, MS, Stone County, MS, Walthall County, MS, Wayne County, MS, Wilkinson County, MS, Anderson County, TX, Cherokee County, TX, Gregg County, TX, Harrison County, TX, Nacogdoches County, TX, Panola County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, Shelby County, TX, Smith County, TX, Upshur County, TX

The watches that followed

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

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 6.7 hours before the alert went out and 138 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, Shreveport, LA at 12:00Z on 2003-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2070 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, Shreveport, LA at 12:00Z on 2003-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.1939Sfc1 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
2070 J/kg
Mixed-layer CIN
-156 J/kg
Mixed-layer LCL
1176 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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
Jul 22, 2:30 PM CDTSevere Thunderstorm WatchSPCConcordia, East Baton Rouge, East Feliciana, Madison, Pointe Coupee, Saint Helena and 4 more6 hr
Jul 22, 4:50 PM CDTMesoscale DiscussionSPCBossier, Caddo, De Soto, Webster85 min
Jul 22, 6:21 PM CDTMesoscale DiscussionSPCEast Carroll, East Feliciana, Franklin, Madison, Richland, Saint Helena and 5 more54 min
Jul 22, 2:49 AM CDTMesoscale DiscussionSPCCoahoma, DeSoto, Quitman, Tunica116 min
Jul 22, 3:45 AM CDTSevere Thunderstorm WatchSPCCalhoun, Chickasaw, Coahoma, DeSoto, Lafayette, Marshall and 6 more5 hr
Jul 22, 4:47 AM CDTMesoscale DiscussionSPCCoahoma, Quitman, Tate, Tunica118 min
Jul 22, 6:29 AM CDTMesoscale DiscussionSPCAlcorn, Benton, DeSoto, Marshall, Prentiss, Tippah and 2 more91 min
Jul 22, 6:40 AM CDTSevere Thunderstorm WatchSPCAlcorn, Benton, Itawamba, Lee, Pontotoc, Prentiss and 3 more3 hr
Jul 22, 2:40 PM CDTSevere Thunderstorm WatchSPCGeorge, Greene, Jackson, Wayne5 hr
Jul 22, 5:10 PM CDTSevere Thunderstorm WatchSPCAnderson, Camp, Cass, Cherokee, Collin, Dallas and 36 more6 hr

Nearby

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