Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 264

March 25, 200912 parishes in Louisiana; 21 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Mar 25, 2009, 5:29 PM CDT for 12 parishes in Louisiana; 21 counties in Texas. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Mar 25, 2009, 5:29 PM CDT (22:29 UTC)
Expired
Mar 25, 2009, 7:00 PM CDT
In force
91 min
Issued by
the Storm Prediction Center
All 33 counties

Avoyelles Parish, LA, Caldwell Parish, LA, Catahoula Parish, LA, Concordia Parish, LA, Grant Parish, LA, LaSalle Parish, LA, Natchitoches Parish, LA, Rapides Parish, LA, Red River Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Winn Parish, LA, Angelina County, TX, Brazos County, TX, Burleson County, TX, Grimes County, TX, Houston County, TX, Jasper County, TX, Lee County, TX, Leon County, TX, Madison County, TX, Milam County, TX, Nacogdoches County, TX, Polk County, TX, Robertson County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Trinity County, TX, Tyler County, TX, Walker County, TX, Washington 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

Shreveport, LA (KSHV), launched 12:00Z, 10.5 hours before the alert went out and 158 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, Shreveport, LA at 12:00Z on 2009-03-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Shreveport, LA at 12:00Z on 2009-03-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -167 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2072 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
-167 m²/s²
0-3 km storm-relative helicity
-133 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.

IssuedProductOfficeCountiesLasted
Mar 24, 7:30 PM CDTMesoscale DiscussionSPCBienville, Caldwell, De Soto, Franklin, Grant, Jackson and 10 more2 hr
Mar 24, 11:25 PM CDTTornado WatchSPCAvoyelles, Caldwell, Catahoula, Concordia, Franklin, Grant and 11 more5 hr
Mar 25, 2:20 AM CDTMesoscale DiscussionSPCAvoyelles, Catahoula, Concordia, Franklin, LaSalle, Madison and 2 more85 min
Mar 25, 2:42 PM CDTMesoscale DiscussionSPCBienville, Bossier, Caddo, Claiborne, Jackson, Lincoln and 1 more93 min
Mar 25, 5:40 PM CDTTornado WatchSPCBienville, Bossier, Caddo, Caldwell, Claiborne, De Soto and 13 more6 hr
Mar 25, 10:55 AM CDTMesoscale DiscussionSPCAnderson, Bell, Blanco, Bosque, Brown, Burleson and 40 more65 min
Mar 25, 11:27 AM CDTSevere Thunderstorm WatchSPCBell, Bosque, Brown, Callahan, Coke, Coleman and 47 more7 hr
Mar 25, 12:51 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bandera, Bastrop, Bexar, Blanco and 48 more114 min
Mar 25, 1:48 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 31 more87 min
Mar 25, 2:06 PM CDTTornado WatchSPCAnderson, Bandera, Bastrop, Bexar, Blanco, Brazos and 36 more7 hr
Mar 25, 3:47 PM CDTMesoscale DiscussionSPCCoryell, Ellis, Falls, Freestone, Henderson, Hill and 8 more88 min
Mar 25, 3:57 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bexar, Blanco, Brazos, Burleson and 31 more93 min

Nearby

Mesoscale Discussions in Texas, 2009Mesoscale Discussions in Louisiana, 2009Every 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.