Alert archive / Louisiana / Mesoscale Discussions in 2003

Mesoscale Discussion 2556

November 26, 20034 states

The Storm Prediction Center issued this mesoscale discussion at Nov 26, 2003, 9:18 PM CST for 4 states. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Nov 26, 2003, 9:18 PM CST (03:18 UTC)
Expired
Nov 26, 2003, 10:45 PM CST
In force
87 min
Issued by
the Storm Prediction Center
All 109 counties

Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Columbia County, AR, Drew County, AR, Lafayette County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Union County, AR, Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Calcasieu Parish, LA, Caldwell Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Claiborne Parish, LA, Concordia Parish, LA, De Soto Parish, LA, East Baton Rouge Parish, LA, East Carroll Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jackson Parish, LA, Jefferson Davis Parish, LA, Lafayette Parish, LA, LaSalle Parish, LA, Lincoln Parish, LA, Livingston Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Natchitoches Parish, LA, Ouachita Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Red River Parish, LA, Richland Parish, LA, Sabine Parish, LA, Saint Helena Parish, LA, Saint James Parish, LA, Saint Landry Parish, LA, Saint Martin Parish, LA, St. Mary Parish, LA, Tensas Parish, LA, Terrebonne Parish, LA, Union Parish, LA, Vermilion Parish, LA, Vernon Parish, LA, Webster Parish, LA, West Baton Rouge Parish, LA, West Carroll Parish, LA, West Feliciana Parish, LA, Winn Parish, LA, Adams County, MS, Amite County, MS, Claiborne County, MS, Copiah County, MS, Franklin County, MS, Hinds County, MS, Humphreys County, MS, Issaquena County, MS, Jefferson County, MS, Lincoln County, MS, Pike County, MS, Sharkey County, MS, Warren County, MS, Washington County, MS, Wilkinson County, MS, Yazoo County, MS, Anderson County, TX, Angelina County, TX, Cass County, TX, Chambers County, TX, Cherokee County, TX, Galveston County, TX, Gregg County, TX, Hardin County, TX, Harrison County, TX, Houston County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Marion County, TX, Nacogdoches County, TX, Newton County, TX, Orange County, TX, Panola County, TX, Polk County, TX, Rusk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Smith County, TX, Trinity County, TX, Tyler 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

Lake Charles Mun, LA (KLCH), launched 00:00Z, 3.3 hours before the alert went out and 69 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, Lake Charles Mun, LA at 00:00Z on 2003-11-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 549 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, Lake Charles Mun, LA at 00:00Z on 2003-11-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 249 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
549 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
540 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
249 m²/s²
0-3 km storm-relative helicity
305 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.0

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 26, 6:55 PM CSTSevere Thunderstorm WatchSPCColumbia, Lafayette, Miller, Nevada6 hr
Nov 27, 1:36 AM CSTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 28 more2 hr
Nov 27, 11:36 AM CSTMesoscale DiscussionSPCArkansas, Bradley, Calhoun, Clark, Cleburne, Cleveland and 38 more114 min
Nov 26, 9:55 PM CSTTornado WatchSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 19 more5 hr
Nov 26, 11:41 PM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Cameron and 18 more94 min
Nov 27, 2:31 AM CSTMesoscale DiscussionSPCAcadia, Allen, Ascension, Assumption, Avoyelles, Calcasieu and 19 more59 min
Nov 27, 3:00 AM CSTTornado WatchSPCAcadia, Ascension, Assumption, Cameron, East Baton Rouge, East Feliciana and 16 more5 hr
Nov 27, 5:03 AM CSTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Cameron, East Baton Rouge, East Feliciana and 16 more117 min
Nov 27, 5:25 AM CSTTornado WatchSPCAscension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 11 more6 hr
Nov 27, 7:48 AM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 10 more117 min
Nov 27, 7:49 AM CSTMesoscale DiscussionSPCAcadia, Calcasieu, Cameron, Iberia, Jefferson Davis, Lafayette and 2 more2 hr
Nov 27, 9:53 AM CSTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, Jefferson, Lafourche, Livingston and 10 more2 hr

Nearby

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