Alert archive / Texas / Mesoscale Discussions in 2003

Mesoscale Discussion 2512

November 17, 20035 parishes in Louisiana; 27 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Nov 17, 2003, 8:10 PM CST for 5 parishes in Louisiana; 27 counties in Texas. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Nov 17, 2003, 8:10 PM CST (02:10 UTC)
Expired
Nov 17, 2003, 9:45 PM CST
In force
95 min
Issued by
the Storm Prediction Center
All 32 counties

Beauregard Parish, LA, Calcasieu Parish, LA, Natchitoches Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Austin County, TX, Brazoria County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Hardin County, TX, Harris County, TX, Jackson County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Jacinto County, TX, Tyler County, TX, Victoria County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 40 km from the middle of the area, began a volume at 02:10 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

Lake Charles Mun, LA (KLCH), launched 00:00Z, 2.2 hours before the alert went out and 173 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 2003-11-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 877 joules per kilogram.LCLEL10008507005003002001001 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 2003-11-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 200 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
877 J/kg
Mixed-layer CIN
-1 J/kg
Mixed-layer LCL
631 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
200 m²/s²
0-3 km storm-relative helicity
222 m²/s²
Significant tornado parameter
1.2
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 17, 7:48 PM CSTMesoscale DiscussionSPCBossier, Caddo, Claiborne, Webster87 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, 4:48 AM CSTMesoscale DiscussionSPCAscension, Assumption, Concordia, East Baton Rouge, East Feliciana, Iberville and 17 more117 min
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 17, 6:55 PM CSTSevere Thunderstorm WatchSPCAustin, Brazoria, Colorado, Fort Bend, Grimes, Harris and 12 more5 hr

Nearby

Mesoscale Discussions in Texas, 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; radar from the NEXRAD Level II archive.