Alert archive / Mississippi / Mesoscale Discussions in 2003

Mesoscale Discussion 2517

November 18, 200323 parishes in Louisiana; 35 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Nov 18, 2003, 4:48 AM CST for 23 parishes in Louisiana; 35 counties in Mississippi. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Nov 18, 2003, 4:48 AM CST (10:48 UTC)
Expired
Nov 18, 2003, 6:45 AM CST
In force
117 min
Issued by
the Storm Prediction Center
All 58 counties

Ascension Parish, LA, Assumption Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Iberville Parish, LA, Lafayette Parish, LA, Livingston Parish, LA, Madison Parish, LA, Pointe Coupee Parish, LA, Saint Charles Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint John the Baptist Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Tangipahoa Parish, LA, Tensas Parish, LA, Vermilion Parish, LA, Washington Parish, LA, West Baton Rouge Parish, LA, West Feliciana Parish, LA, Adams County, MS, Amite County, MS, Attala County, MS, Carroll County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Grenada County, MS, Hinds County, MS, Holmes County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Jefferson Davis County, MS, Lawrence County, MS, Leake County, MS, Leflore County, MS, Lincoln County, MS, Madison County, MS, Montgomery County, MS, Panola County, MS, Pike County, MS, Quitman County, MS, Rankin County, MS, Scott County, MS, Sharkey County, MS, Simpson County, MS, Sunflower County, MS, Tallahatchie County, MS, Tate County, MS, Walthall County, MS, Warren County, MS, Wilkinson County, MS, Yalobusha 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 00:00Z, 10.8 hours before the alert went out and 57 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 00:00Z on 2003-11-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 40 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 00:00Z on 2003-11-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 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
40 J/kg
Mixed-layer CIN
-71 J/kg
Mixed-layer LCL
909 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
91 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
Nov 17, 7:48 PM CSTMesoscale DiscussionSPCBossier, Caddo, Claiborne, Webster87 min
Nov 17, 8:10 PM CSTMesoscale DiscussionSPCBeauregard, Calcasieu, Natchitoches, Sabine, Vernon95 min
Nov 17, 9:25 PM CSTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 12 more7 hr
Nov 17, 10:53 PM CSTMesoscale DiscussionSPCBeauregard, Calcasieu97 min
Nov 17, 11:44 PM CSTMesoscale DiscussionSPCBienville, Bossier, Caldwell, Claiborne, De Soto, Grant and 11 more91 min
Nov 17, 11:50 PM CSTTornado WatchSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 2 more5 hr
Nov 18, 2:08 AM CSTMesoscale DiscussionSPCAscension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 25 more97 min
Nov 18, 2:25 AM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Beauregard and 32 more6 hr
Nov 18, 6:08 AM CSTMesoscale DiscussionSPCAscension, Jefferson, Lafourche, Livingston, Orleans, Plaquemines and 8 more2 hr
Nov 18, 6:55 AM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 11 more5 hr
Nov 18, 10:30 AM CSTMesoscale DiscussionSPCSaint Bernard90 min
Nov 18, 1:29 AM CSTMesoscale DiscussionSPCBolivar, Coahoma, DeSoto, Leflore, Marshall, Panola and 5 more3 hr
Nov 18, 1:55 AM CSTTornado WatchSPCBolivar, Coahoma, DeSoto, Holmes, Humphreys, Leflore and 7 more6 hr
Nov 18, 11:25 AM CSTTornado WatchSPCGeorge, Greene, Jackson6 hr
Nov 18, 2:50 PM CSTSevere Thunderstorm WatchSPCBolivar, Washington5 hr

Nearby

Mesoscale Discussions in Mississippi, 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.