Alert archive / Arkansas / Mesoscale Discussions in 2011

Mesoscale Discussion 774

May 13, 20115 states

The Storm Prediction Center issued this mesoscale discussion at May 13, 2011, 12:01 PM CDT for 5 states. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
May 13, 2011, 12:01 PM CDT (17:01 UTC)
Expired
May 13, 2011, 1:30 PM CDT
In force
89 min
Issued by
the Storm Prediction Center
All 39 counties

Arkansas County, AR, Clay County, AR, Craighead County, AR, Crittenden County, AR, Cross County, AR, Greene County, AR, Jackson County, AR, Jefferson County, AR, Lawrence County, AR, Lee County, AR, Lincoln County, AR, Mississippi County, AR, Monroe County, AR, Phillips County, AR, Poinsett County, AR, Prairie County, AR, Randolph County, AR, St. Francis County, AR, Woodruff County, AR, Carlisle County, KY, Fulton County, KY, Graves County, KY, Hickman County, KY, Butler County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Ripley County, MO, Scott County, MO, Stoddard County, MO, Coahoma County, MS, Tunica County, MS, Dyer County, TN, Lake County, TN, Lauderdale County, TN, Obion County, TN, Shelby County, TN, Tipton County, TN

The radar

The Memphis radar (KNQA), 86 km from the middle of the area, began a volume at 17:03 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

Little Rock, AR (KLZK), launched 12:00Z, 5.0 hours before the alert went out and 108 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, Little Rock, AR at 12:00Z on 2011-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1232 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, Little Rock, AR at 12:00Z on 2011-05-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 105 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
1232 J/kg
Mixed-layer CIN
-20 J/kg
Mixed-layer LCL
494 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
105 m²/s²
0-3 km storm-relative helicity
154 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.1

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
May 12, 9:41 PM CDTMesoscale DiscussionSPCBaxter, Boone, Cleburne, Conway, Crawford, Faulkner and 22 more64 min
May 12, 10:03 PM CDTSevere Thunderstorm WatchSPCBaxter, Cleburne, Conway, Crawford, Faulkner, Franklin and 26 more7 hr
May 12, 10:09 PM CDTMesoscale DiscussionSPCClay66 min
May 13, 12:31 PM CDTSevere Thunderstorm WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 6 more6 hr
May 13, 2:44 PM CDTMesoscale DiscussionSPCCrittenden, Mississippi2 hr
May 13, 11:22 AM CDTMesoscale DiscussionSPCBell, Clay, Harlan, Knox, Leslie, Whitley113 min
May 13, 2:47 PM CDTMesoscale DiscussionSPCHarlan, Letcher58 min
May 13, 5:03 PM CDTMesoscale DiscussionSPCChristian, Hopkins, Logan, Muhlenberg, Todd, Trigg57 min
May 13, 5:54 PM CDTSevere Thunderstorm WatchSPCAllen, Butler, Caldwell, Calloway, Christian, Crittenden and 17 more6 hr
May 12, 9:16 PM CDTMesoscale DiscussionSPCAtchison59 min
May 13, 4:40 PM CDTMesoscale DiscussionSPCLincoln, Saint Charles, Saint Louis, City of Saint Louis95 min
May 13, 12:10 PM CDTSevere Thunderstorm WatchSPCAnderson, Blount, Bradley, Campbell, Carter, Claiborne and 24 more6 hr

Nearby

Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Tennessee, 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.