Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 1439

June 28, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2011, 6:09 PM CDT for 4 states. It was in force for 96 min.

The area

The outline as issued.

The facts

Issued
Jun 28, 2011, 6:09 PM CDT (23:09 UTC)
Expired
Jun 28, 2011, 7:45 PM CDT
In force
96 min
Issued by
the Storm Prediction Center
All 46 counties

Columbia County, AR, Hempstead County, AR, Howard County, AR, Lafayette County, AR, Little River County, AR, Miller County, AR, Nevada County, AR, Sevier County, AR, Union County, AR, Bossier Parish, LA, Caddo Parish, LA, Claiborne Parish, LA, Lincoln Parish, LA, Union Parish, LA, Webster Parish, LA, Atoka County, OK, Bryan County, OK, Choctaw County, OK, Coal County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, McCurtain County, OK, Murray County, OK, Pontotoc County, OK, Pushmataha County, OK, Bowie County, TX, Camp County, TX, Cass County, TX, Collin County, TX, Cooke County, TX, Delta County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Harrison County, TX, Hopkins County, TX, Hunt County, TX, Lamar County, TX, Marion County, TX, Morris County, TX, Rains County, TX, Red River County, TX, Titus County, TX, Upshur County, TX, Wood County, TX

The radar

The Western Arkansas radar (KSRX), 194 km from the middle of the area, began a volume at 23:09 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 (KSHV), launched 12:00Z, 11.2 hours before the alert went out and 201 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 2011-06-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1494 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 2011-06-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -47 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
1494 J/kg
Mixed-layer CIN
-233 J/kg
Mixed-layer LCL
869 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-47 m²/s²
0-3 km storm-relative helicity
-2 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

663 
ACUS11 KWNS 282309
SWOMCD
SPC MCD 282309 
LAZ000-ARZ000-TXZ000-OKZ000-290045-

MESOSCALE DISCUSSION 1439
NWS STORM PREDICTION CENTER NORMAN OK
0609 PM CDT TUE JUN 28 2011

AREAS AFFECTED...SERN OK...NERN TX...SWRN AR...NWRN LA

CONCERNING...SEVERE THUNDERSTORM WATCH 571...572...

VALID 282309Z - 290045Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
571...572...CONTINUES.

SEVERE THUNDERSTORMS WILL CONTINUE TO DEVELOP ALONG THE INTERSECTION
OF A RESIDUAL OUTFLOW BOUNDARY FROM EARLIER CONVECTION AND A SFC
FRONTAL BOUNDARY MAINLY ACROSS SERN OK INTO NERN TX. BEHIND THE
OUTFLOW BOUNDARY...SOME ELEVATED STORMS WILL BE POSSIBLE ACROSS
PARTS OF SRN AR INTO NWRN LA. THESE STORMS MAY BRIEFLY PULSE AND
BECOME STRONG BUT LIKELY WILL NOT BE SEVERE GIVEN THE AIR MASS HAS
BECOME LESS SUPPORTIVE FOR SEVERE DEEP CONVECTION WITH TEMPERATURES
IN THE 70S AND LACKLUSTER MLCAPE LESS THAN 1500 J/KG.

MUCH OF WW 571 WILL LIKELY BE ALLOWED TO EXPIRE AT 00Z...ESPECIALLY
THOSE PORTIONS OVER AR AND LA.  HOWEVER...A LOCAL EXTENSION IN SPACE
AND TIME MAY BE NEEDED OVER NERN TX GIVEN CURRENT STRENGTH AND
MOTION OF THE STORM MOVING OUT OF MCCURTAIN COUNTY OK INTO RIVER
COUNTY TX. GIVEN STORM MOTION TO THE S/SW...THERE MAY BE A NEED FOR
COUNTIES TO BE ADDED TO WW 572 AT SOME POINT AS WELL THIS EVENING.

..LEITMAN.. 06/28/2011

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...LZK...SHV...TSA...FWD...OUN...

LAT...LON   34539724 34979615 34429432 33089213 32369266 32589528
            33389743 34539724

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 27, 7:05 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clay, Fulton and 9 more115 min
Jun 28, 4:08 AM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Clay, Cleburne and 25 more82 min
Jun 28, 4:17 AM CDTSevere Thunderstorm WatchSPCBaxter, Boone, Carroll, Clay, Cleburne, Craighead and 20 more8 hr
Jun 28, 6:34 AM CDTMesoscale DiscussionSPCArkansas, Clay, Cleburne, Conway, Craighead, Crittenden and 28 more86 min
Jun 28, 7:06 AM CDTSevere Thunderstorm WatchSPCArkansas, Bradley, Calhoun, Clark, Cleveland, Conway and 22 more5 hr
Jun 28, 9:52 AM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Chicot, Dallas, Drew and 1 more113 min
Jun 28, 10:26 AM CDTSevere Thunderstorm WatchSPCAshley, Chicot8 hr
Jun 28, 11:42 AM CDTMesoscale DiscussionSPCBradley, Calhoun, Clark, Columbia, Dallas, Garland and 13 more93 min
Jun 28, 11:51 AM CDTSevere Thunderstorm WatchSPCBradley, Calhoun, Clark, Cleveland, Columbia, Conway and 28 more7 hr
Jun 28, 3:09 PM CDTMesoscale DiscussionSPCAshley, Bradley, Calhoun, Clark, Cleveland, Columbia and 27 more96 min
Jun 28, 3:19 PM CDTMesoscale DiscussionSPCConcordia, Tensas116 min
Jun 28, 3:29 PM CDTMesoscale DiscussionSPCCimarron91 min
Jun 28, 3:53 PM CDTSevere Thunderstorm WatchSPCAtoka, Bryan, Carter, Choctaw, Coal, Johnston and 8 more7 hr

Nearby

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