Alert archive / Arkansas / Mesoscale Discussions in 2008

Mesoscale Discussion 550

April 4, 200821 counties in Arkansas; 15 parishes in Louisiana; 15 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2008, 3:34 AM CDT for 21 counties in Arkansas; 15 parishes in Louisiana; 15 counties in Texas. It was in force for 56 min.

The area

The outline as issued.

The facts

Issued
Apr 4, 2008, 3:34 AM CDT (08:34 UTC)
Expired
Apr 4, 2008, 4:30 AM CDT
In force
56 min
Issued by
the Storm Prediction Center
All 51 counties

Arkansas County, AR, Ashley County, AR, Bradley County, AR, Calhoun County, AR, Chicot County, AR, Clark County, AR, Cleveland County, AR, Columbia County, AR, Dallas County, AR, Drew County, AR, Grant County, AR, Hempstead County, AR, Jefferson County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Sevier County, AR, Union County, AR, Bienville Parish, LA, Bossier Parish, LA, Caddo Parish, LA, Caldwell Parish, LA, Claiborne Parish, LA, Franklin Parish, LA, Jackson Parish, LA, Lincoln 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, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Red River County, TX, Smith County, TX, Titus County, TX, Upshur County, TX, Van Zandt County, TX, Wood County, TX

The radar

The Shreveport radar (KSHV), 42 km from the middle of the area, began a volume at 08:35 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

Shreveport, LA (KSHV), launched 00:00Z, 8.6 hours before the alert went out and 37 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 00:00Z on 2008-04-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1498 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2008-04-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
1498 J/kg
Mixed-layer CIN
-44 J/kg
Mixed-layer LCL
1191 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
142 m²/s²
Significant tornado parameter
1.1
Supercell composite
6.5

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
Apr 3, 7:59 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Calhoun, Carroll, Clark and 46 more91 min
Apr 3, 8:21 PM CDTSevere Thunderstorm WatchSPCArkansas, Baxter, Benton, Boone, Calhoun, Carroll and 52 more8 hr
Apr 3, 9:49 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Boone, Clark, Clay, Cleburne and 55 more86 min
Apr 3, 10:23 PM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more4 hr
Apr 3, 11:19 PM CDTMesoscale DiscussionSPCArkansas, Calhoun, Clark, Clay, Cleburne, Cleveland and 45 more86 min
Apr 4, 12:48 AM CDTMesoscale DiscussionSPCBradley, Calhoun, Columbia, Hempstead, Lafayette, Little River and 4 more117 min
Apr 4, 1:28 AM CDTMesoscale DiscussionSPCCrittenden, Lee2 hr
Apr 4, 2:46 AM CDTSevere Thunderstorm WatchSPCLee, Phillips8 hr
Apr 4, 3:55 AM CDTSevere Thunderstorm WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Clark and 19 more7 hr
Apr 4, 7:55 AM CDTMesoscale DiscussionSPCAshley, Chicot2 hr
Apr 4, 5:34 AM CDTSevere Thunderstorm WatchSPCNatchitoches, Sabine6 hr
Apr 4, 9:48 AM CDTTornado WatchSPCAcadia, Allen, Avoyelles, Beauregard, Calcasieu, Caldwell and 23 more9 hr
Apr 4, 4:06 PM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Evangeline, Jefferson Davis and 1 more84 min
Apr 4, 5:02 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more88 min
Apr 4, 5:48 PM CDTTornado WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 14 more6 hr
Apr 3, 8:33 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Clay, Collin, Cooke, Delta and 13 more9 hr
Apr 4, 1:22 AM CDTSevere Thunderstorm WatchSPCBandera, Bell, Blanco, Bosque, Brown, Burnet and 47 more9 hr
Apr 4, 4:14 AM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Bexar, Blanco and 48 more91 min

Nearby

Mesoscale Discussions in Arkansas, 2008Mesoscale Discussions in Louisiana, 2008Mesoscale Discussions in Texas, 2008Every 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.