Alert archive / Louisiana / Mesoscale Discussions in 2009

Mesoscale Discussion 673

May 2, 200918 parishes in Louisiana; Harrison County, Panola County, Rusk County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 2, 2009, 5:10 PM CDT for 18 parishes in Louisiana; Harrison County, Panola County, Rusk County, Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued: May 2, 2009, 5:10 PM CDT (22:10 UTC)
Expired: May 2, 2009, 6:15 PM CDT
In force: 65 min
Issued by: the Storm Prediction Center

All 21 counties

Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, East Carroll Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln Parish, LA, Madison Parish, LA, Morehouse Parish, LA, Ouachita Parish, LA, Red River Parish, LA, Richland Parish, LA, Union Parish, LA, Webster Parish, LA, West Carroll Parish, LA, Harrison County, TX, Panola County, TX, Rusk County, TX

The radar

The Shreveport radar (KSHV), 53 km from the middle of the area, began a volume at 22:12 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.

Tornado Watch 228May 2, 6:05 PM CDT

The nearest sounding before it

Shreveport, LA (KSHV), launched 12:00Z, 10.2 hours before the alert went out and 44 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: 1211 J/kg
Mixed-layer CIN: -39 J/kg
Mixed-layer LCL: 501 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 134 m²/s²
0-3 km storm-relative helicity: 172 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.4

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
May 2, 3:04 PM CDT	Mesoscale Discussion	SPC	Bienville, Bossier, Caddo, Caldwell, Catahoula, Claiborne and 19 more	26 min
May 2, 6:03 PM CDT	Tornado Watch	SPC	Bienville, Bossier, Caddo, Claiborne, De Soto, East Carroll and 10 more	6 hr
May 1, 7:19 PM CDT	Mesoscale Discussion	SPC	Archer, Baylor, Childress, Clay, Cooke, Cottle and 21 more	86 min
May 1, 9:36 PM CDT	Mesoscale Discussion	SPC	Fannin, Lamar	84 min
May 2, 2:58 AM CDT	Mesoscale Discussion	SPC	Collingsworth, Gray, Hemphill, Wheeler	3 hr
May 2, 9:23 AM CDT	Mesoscale Discussion	SPC	Bowie, Delta, Lamar, Red River	97 min
May 2, 12:17 PM CDT	Tornado Watch	SPC	Bowie, Camp, Cass, Collin, Delta, Denton and 15 more	7 hr
May 2, 1:24 PM CDT	Mesoscale Discussion	SPC	Bell, Blanco, Bosque, Burnet, Collin, Coryell and 31 more	66 min
May 2, 1:56 PM CDT	Tornado Watch	SPC	Bell, Bosque, Coryell, Dallas, Ellis, Falls and 18 more	4 hr
May 2, 3:47 PM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Dallas, Delta, Franklin and 12 more	58 min
May 2, 5:25 PM CDT	Mesoscale Discussion	SPC	Bowie	95 min
May 2, 6:49 PM CDT	Mesoscale Discussion	SPC	Camp, Cass, Franklin, Hopkins, Hunt, Kaufman and 7 more	86 min

Nearby

Mesoscale Discussions in Louisiana, 2009 Mesoscale Discussions in Texas, 2009 Every mesoscale discussion in 2009

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.