Alert archive / Oklahoma / Mesoscale Discussions in 2011

Mesoscale Discussion 157

February 27, 201113 counties in Arkansas; 31 counties in Oklahoma; 11 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Feb 27, 2011, 8:07 PM CST for 13 counties in Arkansas; 31 counties in Oklahoma; 11 counties in Texas. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Feb 27, 2011, 8:07 PM CST (02:07 UTC)
Expired
Feb 27, 2011, 9:00 PM CST
In force
53 min
Issued by
the Storm Prediction Center
All 55 counties

Crawford County, AR, Franklin County, AR, Howard County, AR, Little River County, AR, Logan County, AR, Madison County, AR, Montgomery County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Washington County, AR, Adair County, OK, Atoka County, OK, Bryan County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Craig County, OK, Creek County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Marshall County, OK, Mayes County, OK, McCurtain County, OK, McIntosh County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Okmulgee County, OK, Osage County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK, Bowie County, TX, Camp County, TX, Delta County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Hopkins County, TX, Lamar County, TX, Morris County, TX, Red River County, TX, Titus County, TX

The radar

The Western Arkansas radar (KSRX), 88 km from the middle of the area, began a volume at 02:13 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

Springfield, MO (KSGF), launched 00:00Z, 2.1 hours before the alert went out and 256 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, Springfield, MO at 00:00Z on 2011-02-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 626 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, Springfield, MO at 00:00Z on 2011-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 369 square meters per square second.1939587897117136156Sfc1 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
626 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
1011 m above ground
0-6 km bulk shear
65 kt
0-1 km storm-relative helicity
369 m²/s²
0-3 km storm-relative helicity
472 m²/s²
Significant tornado parameter
1.5
Supercell composite
7.4

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
Feb 27, 10:04 PM CSTTornado WatchSPCBaxter, Benton, Boone, Carroll, Clark, Cleburne and 41 more6 hr
Feb 27, 11:49 PM CSTMesoscale DiscussionSPCClark, Conway, Crawford, Franklin, Garland, Hempstead and 20 more86 min
Feb 28, 1:05 AM CSTMesoscale DiscussionSPCClay, Craighead, Crittenden, Cross, Greene, Mississippi and 2 more25 min
Feb 28, 1:33 AM CSTTornado WatchSPCClay, Craighead, Crittenden, Cross, Greene, Lawrence and 4 more7 hr
Feb 28, 5:28 AM CSTMesoscale DiscussionSPCAshley, Chicot, Desha, Phillips62 min
Feb 28, 5:59 AM CSTTornado WatchSPCLee, Phillips7 hr
Feb 27, 10:54 PM CSTMesoscale DiscussionSPCAnderson, Bell, Bosque, Cherokee, Collin, Coryell and 24 more96 min

Nearby

Mesoscale Discussions in Oklahoma, 2011Mesoscale Discussions in Arkansas, 2011Mesoscale Discussions in Texas, 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.