Alert archive / Texas / Mesoscale Discussions in 2016

Mesoscale Discussion 510

April 30, 2016Calhoun County, Union County, Arkansas; 11 parishes in Louisiana; 13 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 30, 2016, 3:23 AM CDT for Calhoun County, Union County, Arkansas; 11 parishes in Louisiana; 13 counties in Texas. It was in force for 97 min.

The area

The outline as issued.

The facts

Issued
Apr 30, 2016, 3:23 AM CDT (08:23 UTC)
Expired
Apr 30, 2016, 5:00 AM CDT
In force
97 min
Issued by
the Storm Prediction Center
All 26 counties

Calhoun County, AR, Union County, AR, Beauregard Parish, LA, Bienville Parish, LA, Bossier Parish, LA, Claiborne Parish, LA, De Soto Parish, LA, Lincoln Parish, LA, Natchitoches Parish, LA, Red River Parish, LA, Sabine Parish, LA, Vernon Parish, LA, Webster Parish, LA, Hardin County, TX, Harris County, TX, Jasper County, TX, Jefferson County, TX, Liberty County, TX, Newton County, TX, Orange County, TX, Polk County, TX, Sabine County, TX, San Augustine County, TX, San Jacinto County, TX, Shelby County, TX, Tyler County, TX

The radar

The Ft Polk radar (KPOE), 90 km from the middle of the area, began a volume at 08:22 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 (KBAD), launched 00:00Z, 8.4 hours before the alert went out and 109 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 2016-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 835 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 2016-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 455 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
835 J/kg
Mixed-layer CIN
-28 J/kg
Mixed-layer LCL
591 m above ground
0-6 km bulk shear
68 kt
0-1 km storm-relative helicity
455 m²/s²
0-3 km storm-relative helicity
577 m²/s²
Significant tornado parameter
2.9
Supercell composite
11.8

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 8:56 PM CDTMesoscale DiscussionSPCBradley, Calhoun, Columbia, Hempstead, Lafayette, Little River and 4 more94 min
Apr 29, 9:58 PM CDTSevere Thunderstorm WatchSPCColumbia, Hempstead, Howard, Lafayette, Little River, Miller and 3 more7 hr
Apr 29, 11:42 PM CDTMesoscale DiscussionSPCBradley, Columbia, Lafayette, Little River, Miller, Nevada and 2 more93 min
Apr 30, 3:02 PM CDTMesoscale DiscussionSPCBaxter, Boone, Conway, Johnson, Logan, Marion and 5 more118 min
Apr 30, 3:59 PM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Cleburne, Conway, Faulkner, Fulton and 13 more6 hr
Apr 30, 5:11 AM CDTSevere Thunderstorm WatchSPCAcadia, Allen, Avoyelles, Beauregard, Bienville, Calcasieu and 22 more9 hr
Apr 30, 7:38 AM CDTMesoscale DiscussionSPCAcadia, Allen, Beauregard, Calcasieu, Cameron, Evangeline and 2 more67 min
Apr 30, 10:22 AM CDTMesoscale DiscussionSPCAcadia, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge and 16 more53 min
Apr 30, 11:38 AM CDTSevere Thunderstorm WatchSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberville, Jefferson and 16 more7 hr
Apr 30, 1:35 PM CDTMesoscale DiscussionSPCAscension, Assumption, East Baton Rouge, East Feliciana, Iberia, Iberville and 22 more55 min
Apr 30, 4:00 PM CDTMesoscale DiscussionSPCAscension, Assumption, Jefferson, Lafourche, Livingston, Orleans and 10 more2 hr
Apr 29, 8:07 PM CDTMesoscale DiscussionSPCBandera, Bastrop, Bell, Bexar, Blanco, Bosque and 29 more83 min
Apr 29, 8:20 PM CDTSevere Thunderstorm WatchSPCBandera, Bastrop, Bexar, Blanco, Burnet, Caldwell and 19 more9 hr
Apr 30, 1:46 AM CDTMesoscale DiscussionSPCBandera, Bexar, Blanco, Comal, Hays, Kendall and 3 more59 min
Apr 30, 5:12 AM CDTMesoscale DiscussionSPCAustin, Burleson, Colorado, Fayette, Grimes, Harris and 7 more93 min
Apr 30, 5:27 AM CDTSevere Thunderstorm WatchSPCAustin, Brazoria, Brazos, Burleson, Chambers, Colorado and 11 more6 hr

Nearby

Mesoscale Discussions in Texas, 2016Mesoscale Discussions in Louisiana, 2016Mesoscale Discussions in Arkansas, 2016Every mesoscale discussion in 2016

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.