Alert archive / Arkansas / Mesoscale Discussions in 2015

Mesoscale Discussion 249

April 9, 20154 states

The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2015, 2:15 PM CDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 9, 2015, 2:15 PM CDT (19:15 UTC)
Expired
Apr 9, 2015, 4:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 54 counties

Arkansas County, AR, Bradley County, AR, Calhoun County, AR, Clark County, AR, Cleburne County, AR, Cleveland County, AR, Columbia County, AR, Conway County, AR, Dallas County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hempstead County, AR, Hot Spring County, AR, Howard County, AR, Jefferson County, AR, Lafayette County, AR, Lincoln County, AR, Little River County, AR, Lonoke County, AR, Miller County, AR, Monroe County, AR, Montgomery County, AR, Nevada County, AR, Ouachita County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Prairie County, AR, Pulaski County, AR, Saline County, AR, Sevier County, AR, Union County, AR, Van Buren County, AR, White County, AR, Woodruff County, AR, Yell County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Webster Parish, LA, McCurtain County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Franklin County, TX, Gregg County, TX, Harrison County, TX, Marion County, TX, Morris County, TX, Red River County, TX, Titus County, TX, Upshur County, TX

The radar

The Little Rock radar (KLZK), 123 km from the middle of the area, began a volume at 19:15 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 12:00Z, 7.3 hours before the alert went out and 195 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 2015-04-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 641 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 2015-04-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 207 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
641 J/kg
Mixed-layer CIN
-116 J/kg
Mixed-layer LCL
674 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
207 m²/s²
0-3 km storm-relative helicity
244 m²/s²
Significant tornado parameter
0.3
Supercell composite
4.1

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 9, 2:32 PM CDTSevere Thunderstorm WatchSPCBenton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more7 hr
Apr 9, 3:06 PM CDTTornado WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 13 more7 hr
Apr 9, 3:17 PM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Cleburne, Conway, Faulkner, Fulton and 29 more7 hr
Apr 9, 6:11 PM CDTMesoscale DiscussionSPCArkansas, Baxter, Bradley, Calhoun, Clark, Clay and 57 more64 min
Apr 9, 6:32 PM CDTSevere Thunderstorm WatchSPCAshley, Chicot, Clay, Craighead, Crittenden, Cross and 8 more5 hr
Apr 8, 7:45 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Custer and 22 more90 min
Apr 9, 1:32 PM CDTMesoscale DiscussionSPCOttawa118 min
Apr 8, 7:23 PM CDTSevere Thunderstorm WatchSPCBorden, Childress, Coke, Cottle, Crosby, Dawson and 27 more3 hr
Apr 8, 9:34 PM CDTMesoscale DiscussionSPCArcher, Baylor, Haskell, Throckmorton, Wichita, Wilbarger and 1 more56 min
Apr 9, 4:53 PM CDTMesoscale DiscussionSPCBosque, Collin, Comanche, Dallas, Denton, Erath and 8 more2 hr

Nearby

Mesoscale Discussions in Arkansas, 2015Mesoscale Discussions in Texas, 2015Mesoscale Discussions in Louisiana, 2015Every mesoscale discussion in 2015

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.