Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 561

April 24, 201121 counties in Arkansas; McCurtain County, Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2011, 10:13 PM CDT for 21 counties in Arkansas; McCurtain County, Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 24, 2011, 10:13 PM CDT (03:13 UTC)
Expired
Apr 25, 2011, 12:15 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 22 counties

Clark County, AR, Cleburne County, AR, Conway County, AR, Faulkner County, AR, Garland County, AR, Grant County, AR, Hot Spring County, AR, Howard County, AR, Logan County, AR, Lonoke County, AR, Montgomery County, AR, Perry County, AR, Pike County, AR, Polk County, AR, Pope County, AR, Pulaski County, AR, Saline County, AR, Scott County, AR, Sevier County, AR, Van Buren County, AR, Yell County, AR, McCurtain County, OK

The radar

The Little Rock radar (KLZK), 110 km from the middle of the area, began a volume at 03:16 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 (KSHV), launched 00:00Z, 3.2 hours before the alert went out and 239 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 2011-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 253 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 2011-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 44 square meters per square second.193958Sfc1 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
253 J/kg
Mixed-layer CIN
-162 J/kg
Mixed-layer LCL
1930 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
44 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.1

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 24, 11:43 PM CDTSevere Thunderstorm WatchSPCHempstead, Howard, Little River, Miller, Nevada, Sevier5 hr
Apr 25, 1:57 AM CDTMesoscale DiscussionSPCCleveland, Dallas, Jefferson, Lincoln63 min
Apr 25, 4:41 AM CDTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Columbia and 25 more7 hr
Apr 25, 7:23 AM CDTMesoscale DiscussionSPCCalhoun, Clark, Cleveland, Columbia, Dallas, Garland and 11 more97 min
Apr 25, 8:37 AM CDTMesoscale DiscussionSPCArkansas, Cleveland, Crittenden, Desha, Drew, Jefferson and 7 more53 min
Apr 25, 9:17 AM CDTSevere Thunderstorm WatchSPCCrittenden, Lee, Phillips, St. Francis6 hr
Apr 25, 10:46 AM CDTMesoscale DiscussionSPCHempstead, Howard, Lafayette, Little River, Miller, Sevier59 min
Apr 25, 11:00 AM CDTTornado WatchSPCCarroll, Clark, Crawford, Franklin, Hempstead, Howard and 13 more7 hr
Apr 25, 1:15 PM CDTMesoscale DiscussionSPCCrittenden, Cross, Lee, Phillips, St. Francis60 min
Apr 25, 1:28 PM CDTMesoscale DiscussionSPCCrawford, Franklin, Howard, Johnson, Little River, Logan and 5 more92 min
Apr 25, 3:08 PM CDTMesoscale DiscussionSPCArkansas, Ashley, Baxter, Boone, Bradley, Calhoun and 29 more37 min
Apr 25, 3:22 PM CDTTornado Watch PDSSPCArkansas, Baxter, Boone, Bradley, Calhoun, Clark and 50 more8 hr
Apr 25, 4:34 PM CDTMesoscale DiscussionSPCArkansas, Clay, Craighead, Crittenden, Cross, Greene and 11 more56 min
Apr 25, 4:50 PM CDTTornado Watch PDSSPCClay, Craighead, Crittenden, Cross, Greene, Lee and 4 more7 hr
Apr 24, 7:35 PM CDTMesoscale DiscussionSPCBeaver2 hr
Apr 24, 11:58 PM CDTMesoscale DiscussionSPCAlfalfa, Beaver, Blaine, Canadian, Custer, Dewey and 14 more92 min
Apr 25, 5:24 PM CDTMesoscale DiscussionSPCBeckham, Caddo, Canadian, Cleveland, Comanche, Cotton and 13 more66 min

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Oklahoma, 2011Every mesoscale discussion in 2011

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.