Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 730

May 11, 201126 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 11, 2011, 9:56 AM CDT for 26 counties in Texas. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 11, 2011, 9:56 AM CDT (14:56 UTC)
Expired
May 11, 2011, 11:30 AM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 26 counties

Bosque County, TX, Brown County, TX, Callahan County, TX, Coleman County, TX, Comanche County, TX, Concho County, TX, Eastland County, TX, Edwards County, TX, Erath County, TX, Hamilton County, TX, Hood County, TX, Kimble County, TX, Mason County, TX, McCulloch County, TX, Menard County, TX, Mills County, TX, Palo Pinto County, TX, Parker County, TX, Runnels County, TX, San Saba County, TX, Schleicher County, TX, Somervell County, TX, Stephens County, TX, Sutton County, TX, Val Verde County, TX, Young County, TX

The radar

The San Angelo radar (KSJT), 97 km from the middle of the area, began a volume at 14:58 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

Del Rio, TX (KDRT), launched 12:00Z, 2.9 hours before the alert went out and 249 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, Del Rio, TX at 12:00Z on 2011-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2847 joules per kilogram.LCLEL10008507005003002001001 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, Del Rio, TX at 12:00Z on 2011-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.1939587897Sfc1 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
2847 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
565 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
254 m²/s²
Significant tornado parameter
3.3
Supercell composite
15.6

Open this sounding in Storm Lab

The text

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

435 
ACUS11 KWNS 111456
SWOMCD
SPC MCD 111456 
TXZ000-111630-

MESOSCALE DISCUSSION 0730
NWS STORM PREDICTION CENTER NORMAN OK
0956 AM CDT WED MAY 11 2011

AREAS AFFECTED...CNTRL TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 111456Z - 111630Z

STORMS MAY UNDERGO SOME INTENSIFICATION AS THEY DEVELOP EWD THROUGH
CNTRL TX. INITIAL THREAT IS EXPECTED TO BE DAMAGING WIND AND LARGE
HAIL...THOUGH A COUPLE OF TORNADOES CANNOT BE RULED OUT. AREA IS
BEING MONITORED FOR A POSSIBLE WW.

THIS MORNING STORMS CONTINUE DEVELOPING FROM NE OF SANDERSON TO NEAR
ABILENE. THE ATMOSPHERE DOWNSTREAM IS MODERATELY UNSTABLE WITH STEEP
MID LEVEL LAPSE RATES. HOWEVER...THE BOUNDARY LAYER HAS NOT
UNDERGONE SIGNIFICANT DESTABILIZATION DUE TO TIME OF DAY AND SOME
CONVECTIVE INHIBITION PERSISTS. THE STORMS APPEAR TO BE DEVELOPING
WITHIN A ZONE OF PRE-FRONTAL CONVERGENCE FORCED BY AN EJECTING LEAD
SHORTWAVE TROUGH. THE LLJ WILL GRADUALLY VEER AND SHIFT EWD AS THE
IMPULSE CONTINUE NEWD THROUGH THE SRN/CNTRL PLAINS. THE STORMS WILL
REMAIN EMBEDDED WITHIN EFFECTIVE SHEAR /35-45 KT/ SUFFICIENT FOR
ORGANIZED STORMS WITH DAMAGING WIND AND LARGE HAIL EXPECTED TO BE
THE INITIAL PRIMARY THREATS.

..DIAL.. 05/11/2011

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

ATTN...WFO...FWD...EWX...SJT...

LAT...LON   29660046 30000157 33139902 33259781 31959753 29660046

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 11, 2:28 AM CDTMesoscale DiscussionSPCArmstrong, Bailey, Borden, Briscoe, Carson, Castro and 31 more92 min
May 11, 3:29 AM CDTSevere Thunderstorm WatchSPCAndrews, Armstrong, Bailey, Borden, Briscoe, Carson and 46 more8 hr
May 11, 7:30 AM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Childress, Coke and 43 more60 min
May 11, 10:21 AM CDTSevere Thunderstorm WatchSPCBell, Bosque, Brown, Burnet, Callahan, Coleman and 52 more5 hr
May 11, 1:16 PM CDTSevere Thunderstorm WatchSPCClay8 hr
May 11, 2:51 PM CDTMesoscale DiscussionSPCBosque, Bowie, Camp, Cass, Collin, Coryell and 31 more84 min
May 11, 3:46 PM CDTSevere Thunderstorm WatchSPCAnderson, Bell, Blanco, Bosque, Bowie, Burnet and 44 more8 hr
May 11, 6:35 PM CDTMesoscale DiscussionSPCBowie, Camp, Morris, Titus55 min

Nearby

Mesoscale 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.