Alert archive / Louisiana / Mesoscale Discussions in 2008

Mesoscale Discussion 557

April 4, 20087 parishes in Louisiana; Hardin County, Newton County, Orange County, Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2008, 4:06 PM CDT for 7 parishes in Louisiana; Hardin County, Newton County, Orange County, Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued: Apr 4, 2008, 4:06 PM CDT (21:06 UTC)
Expired: Apr 4, 2008, 5:30 PM CDT
In force: 84 min
Issued by: the Storm Prediction Center

Counties Acadia Parish, LA, Allen Parish, LA, Beauregard Parish, LA, Calcasieu Parish, LA, Evangeline Parish, LA, Jefferson Davis Parish, LA, Vernon Parish, LA, Hardin County, TX, Newton County, TX, Orange County, TX

The radar

The Lake Charles radar (KLCH), 45 km from the middle of the area, began a volume at 21:09 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 nearest sounding before it

Lake Charles Mun, LA (KLCH), launched 12:00Z, 9.1 hours before the alert went out and 46 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: 900 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 619 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 144 m²/s²
0-3 km storm-relative helicity: 249 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.8

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 4, 12:48 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, Jackson and 8 more	117 min
Apr 4, 3:34 AM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Caldwell, Claiborne, Franklin and 9 more	56 min
Apr 4, 3:55 AM CDT	Severe Thunderstorm Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, East Carroll and 8 more	7 hr
Apr 4, 5:34 AM CDT	Severe Thunderstorm Watch	SPC	Natchitoches, Sabine	6 hr
Apr 4, 7:55 AM CDT	Mesoscale Discussion	SPC	Caldwell, East Carroll, Franklin, Jackson, Madison, Morehouse and 5 more	2 hr
Apr 4, 9:48 AM CDT	Tornado Watch	SPC	Acadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 23 more	9 hr
Apr 4, 5:02 PM CDT	Mesoscale Discussion	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more	88 min
Apr 4, 5:48 PM CDT	Tornado Watch	SPC	Ascension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 14 more	6 hr
Apr 3, 7:59 PM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Clay, Collin, Cooke and 16 more	91 min
Apr 3, 8:21 PM CDT	Severe Thunderstorm Watch	SPC	Bowie, Camp, Cass, Franklin, Morris, Red River and 1 more	8 hr
Apr 3, 8:33 PM CDT	Severe Thunderstorm Watch	SPC	Archer, Baylor, Clay, Collin, Cooke, Delta and 13 more	9 hr
Apr 3, 9:49 PM CDT	Mesoscale Discussion	SPC	Archer, Clay, Cooke, Delta, Denton, Fannin and 6 more	86 min
Apr 3, 11:19 PM CDT	Mesoscale Discussion	SPC	Archer, Bowie, Clay, Collin, Cooke, Delta and 13 more	86 min
Apr 4, 1:22 AM CDT	Severe Thunderstorm Watch	SPC	Bandera, Bell, Blanco, Bosque, Brown, Burnet and 47 more	9 hr
Apr 4, 4:14 AM CDT	Mesoscale Discussion	SPC	Anderson, Bandera, Bastrop, Bell, Bexar, Blanco and 48 more	91 min

Nearby

Mesoscale Discussions in Louisiana, 2008 Mesoscale Discussions in Texas, 2008 Every mesoscale discussion in 2008

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.