Alert archive / Arkansas / Mesoscale Discussions in 2017

Mesoscale Discussion 562

April 26, 201715 counties in Arkansas; Bossier Parish, Caddo Parish, Louisiana; 12 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2017, 1:05 PM CDT for 15 counties in Arkansas; Bossier Parish, Caddo Parish, Louisiana; 12 counties in Texas. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued
Apr 26, 2017, 1:05 PM CDT (18:05 UTC)
Expired
Apr 26, 2017, 2:30 PM CDT
In force
85 min
Issued by
the Storm Prediction Center
All 29 counties

Clark County, AR, Columbia County, AR, Dallas County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Jefferson County, AR, Lafayette County, AR, Lonoke County, AR, Miller County, AR, Nevada County, AR, Ouachita County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Bossier Parish, LA, Caddo Parish, LA, Anderson County, TX, Cass County, TX, Cherokee County, TX, Gregg County, TX, Harrison County, TX, Henderson County, TX, Marion County, TX, Morris County, TX, Panola County, TX, Rusk County, TX, Smith County, TX, Upshur County, TX

The radar

The Shreveport radar (KSHV), 79 km from the middle of the area, began a volume at 18:05 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

Shreveport, LA (KBAD), launched 12:00Z, 6.1 hours before the alert went out and 78 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 2017-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 761 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 12:00Z on 2017-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 324 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
761 J/kg
Mixed-layer CIN
-435 J/kg
Mixed-layer LCL
770 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
324 m²/s²
0-3 km storm-relative helicity
327 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 25, 10:51 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Washington54 min
Apr 25, 11:27 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more7 hr
Apr 26, 1:42 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Crawford, Franklin, Johnson and 10 more2 hr
Apr 26, 5:37 AM CDTMesoscale DiscussionSPCConway, Crawford, Franklin, Garland, Howard, Johnson and 14 more113 min
Apr 26, 6:00 AM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 23 more7 hr
Apr 26, 7:29 AM CDTMesoscale DiscussionSPCBaxter, Boone, Carroll, Conway, Crawford, Franklin and 23 more2 hr
Apr 26, 9:39 AM CDTMesoscale DiscussionSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 47 more36 min
Apr 26, 10:08 AM CDTTornado WatchSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 51 more7 hr
Apr 26, 3:53 PM CDTMesoscale DiscussionSPCClay97 min
Apr 26, 4:23 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 19 more67 min
Apr 26, 4:44 PM CDTTornado WatchSPCArkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 11 more5 hr
Apr 26, 5:02 PM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lee and 4 more6 hr
Apr 26, 6:10 PM CDTMesoscale DiscussionSPCMississippi95 min

Nearby

Mesoscale Discussions in Arkansas, 2017Mesoscale Discussions in Texas, 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.