Alert archive / Louisiana / Mesoscale Discussions in 2005

Mesoscale Discussion 691

April 26, 200540 parishes in Louisiana; 26 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2005, 6:37 AM CDT for 40 parishes in Louisiana; 26 counties in Mississippi. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Apr 26, 2005, 6:37 AM CDT (11:37 UTC)
Expired: Apr 26, 2005, 8:00 AM CDT
In force: 83 min
Issued by: the Storm Prediction Center

All 66 counties

Acadia Parish, LA, Allen Parish, LA, Ascension Parish, LA, Assumption Parish, LA, Avoyelles Parish, LA, Calcasieu Parish, LA, Cameron Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, East Baton Rouge Parish, LA, East Feliciana Parish, LA, Evangeline Parish, LA, Franklin Parish, LA, Grant Parish, LA, Iberia Parish, LA, Iberville Parish, LA, Jefferson Davis Parish, LA, Jefferson Parish, LA, Lafayette Parish, LA, Lafourche Parish, LA, LaSalle Parish, LA, Livingston Parish, LA, Orleans Parish, LA, Pointe Coupee Parish, LA, Rapides Parish, LA, Saint Bernard 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, Saint Tammany 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, Claiborne County, MS, Copiah County, MS, Covington County, MS, Forrest County, MS, Franklin County, MS, George County, MS, Greene County, MS, Hancock County, MS, Harrison 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

The watches that followed

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

Severe Thunderstorm Watch 205Apr 26, 7:40 AM CDT

The nearest sounding before it

Jackson, MS (KJAN), launched 00:00Z, 11.6 hours before the alert went out and 243 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1571 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 214 m²/s²
0-3 km storm-relative helicity: 217 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.

Issued	Product	Office	Counties	Lasted
Apr 25, 8:46 PM CDT	Mesoscale Discussion	SPC	Bossier, Caddo, Webster	29 min
Apr 25, 10:49 PM CDT	Mesoscale Discussion	SPC	Bossier, Caddo, De Soto	86 min
Apr 25, 11:20 PM CDT	Severe Thunderstorm Watch	SPC	Webster	7 hr
Apr 26, 1:24 AM CDT	Mesoscale Discussion	SPC	Bossier, Caddo, Claiborne, Lincoln, Morehouse, Union and 1 more	2 hr
Apr 26, 7:40 AM CDT	Severe Thunderstorm Watch	SPC	Ascension, Assumption, Avoyelles, Catahoula, Concordia, East Baton Rouge and 25 more	8 hr
Apr 26, 1:54 PM CDT	Mesoscale Discussion	SPC	Jefferson, Livingston, Orleans, Plaquemines, Saint Bernard, Saint Charles and 5 more	66 min
Apr 26, 11:05 AM CDT	Mesoscale Discussion	SPC	Forrest, George, Greene, Hancock, Harrison, Jackson and 4 more	115 min

Nearby

Mesoscale Discussions in Louisiana, 2005 Mesoscale Discussions in Mississippi, 2005 Every 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.