Alert archive / Texas / Mesoscale Discussions in 2017

Mesoscale Discussion 480

April 10, 201711 counties in Arkansas; Bossier Parish, Caddo Parish, Webster Parish, Louisiana; 63 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 10, 2017, 6:51 PM CDT for 11 counties in Arkansas; Bossier Parish, Caddo Parish, Webster Parish, Louisiana; 63 counties in Texas. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Apr 10, 2017, 6:51 PM CDT (23:51 UTC)
Expired
Apr 10, 2017, 8:15 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
All 77 counties

Clark County, AR, Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Pike County, AR, Sevier County, AR, Bossier Parish, LA, Caddo Parish, LA, Webster Parish, LA, Anderson County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Bowie County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Camp County, TX, Cass County, TX, Cherokee County, TX, Comal County, TX, Coryell County, TX, Edwards County, TX, Ellis County, TX, Falls County, TX, Franklin County, TX, Freestone County, TX, Gillespie County, TX, Gregg County, TX, Grimes County, TX, Hamilton County, TX, Harrison County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hopkins County, TX, Houston County, TX, Kaufman County, TX, Kendall County, TX, Kerr County, TX, Kimble County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Marion County, TX, Mason County, TX, McLennan County, TX, Milam County, TX, Morris County, TX, Nacogdoches County, TX, Navarro County, TX, Panola County, TX, Rains County, TX, Real County, TX, Red River County, TX, Robertson County, TX, Rusk County, TX, San Saba County, TX, Smith County, TX, Sutton County, TX, Titus County, TX, Travis County, TX, Upshur County, TX, Van Zandt County, TX, Williamson County, TX, Wood County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 109 km from the middle of the area, began a volume at 23:54 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

Fort Worth, TX (KFWD), launched 12:00Z, 11.9 hours before the alert went out and 135 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, Fort Worth, TX at 12:00Z on 2017-04-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 784 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, Fort Worth, TX at 12:00Z on 2017-04-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 313 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
784 J/kg
Mixed-layer CIN
-234 J/kg
Mixed-layer LCL
738 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
313 m²/s²
0-3 km storm-relative helicity
344 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.2

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 10, 2:26 PM CDTSevere Thunderstorm WatchSPCHempstead, Howard, Lafayette, Little River, Miller, Nevada and 1 more9 hr
Apr 10, 5:43 PM CDTMesoscale DiscussionSPCMarion, Newton2 hr
Apr 10, 12:17 PM CDTMesoscale DiscussionSPCBastrop, Bell, Blanco, Bosque, Burnet, Collin and 36 more2 hr

Nearby

Mesoscale Discussions in Texas, 2017Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Louisiana, 2017Every mesoscale discussion in 2017

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.