Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 562

April 24, 201145 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2011, 11:25 PM CDT for 45 counties in Texas. It was in force for 65 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2011, 11:25 PM CDT (04:25 UTC)
Expired
Apr 25, 2011, 12:30 AM CDT
In force
65 min
Issued by
the Storm Prediction Center
All 45 counties

Bosque County, TX, Brown County, TX, Callahan County, TX, Camp County, TX, Coke County, TX, Coleman County, TX, Collin County, TX, Comanche County, TX, Cooke County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Eastland County, TX, Ellis County, TX, Erath County, TX, Fannin County, TX, Franklin County, TX, Grayson County, TX, Hamilton County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Kaufman County, TX, Lamar County, TX, Mills County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Rockwall County, TX, Runnels County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Tarrant County, TX, Taylor County, TX, Van Zandt County, TX, Wise County, TX, Wood County, TX, Young County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 32 km from the middle of the area, began a volume at 04:25 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

Fort Worth, TX (KFWD), launched 00:00Z, 4.4 hours before the alert went out and 31 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, Fort Worth, TX at 00:00Z on 2011-04-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1679 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, Fort Worth, TX at 00:00Z on 2011-04-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 98 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
1679 J/kg
Mixed-layer CIN
-14 J/kg
Mixed-layer LCL
1811 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
98 m²/s²
0-3 km storm-relative helicity
153 m²/s²
Significant tornado parameter
0.3
Supercell composite
6.0

Open this sounding in Storm Lab

The text

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

971 
ACUS11 KWNS 250425
SWOMCD
SPC MCD 250425 
TXZ000-OKZ000-250530-

MESOSCALE DISCUSSION 0562
NWS STORM PREDICTION CENTER NORMAN OK
1125 PM CDT SUN APR 24 2011

AREAS AFFECTED...PORTIONS W-CENTRAL THROUGH NE TX.

CONCERNING...TORNADO WATCH 196...

VALID 250425Z - 250530Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 196 CONTINUES.

WW 196 SCHEDULED TO EXPIRE AT 05Z.  HOWEVER...THREAT FOR SVR HAIL
AND GUSTS WILL PERSIST OVER PORTIONS OF THIS REGION FOR A FEW MORE
HOURS...AND REPLACEMENT SVR TSTM WW MAY BE NEEDED BEFORE 05Z.

SFC MESOANALYSIS SHOWS OUTFLOW BOUNDARY FROM RED RIVER COUNTY TO
DALLAS COUNTY...SWWD TOWARD SUPERCELLS MOVING EWD BETWEEN
SEP-BWD...THEN NWWD ACROSS SWW/SNK AREAS.  THIS BOUNDARY INTERSECTS
NWWD-RETREATING DRYLINE OVER MITCHELL COUNTY...S OF SFC COLD FRONT. 
ADDITIONAL TSTMS HAVE DEVELOPED W OF WW NEAR THAT INTERSECTION...IN
ENVIRONMENT THAT MAINTAINS SUFFICIENT BUOYANCY AND DEEP-LAYER SHEAR
TO SUPPORT ORGANIZED SVR THREAT WITH SIGNIFICANT-SVR HAIL POSSIBLE. 
SUPERCELLS NEAR SEP MAY HAVE BEGIN WEAKENING TREND...BUT WILL
CONTINUE TO POSE DAMAGING HAIL THREAT FOR AS LONG AS THEY CAN
PERSIST IN FACE OF MLCINH THAT WILL STRENGTHEN WITH BOTH TIME AND
EWD EXTENT.  EFFECTIVE SHEAR WILL REMAIN LARGE ENOUGH WITH 45-55 KT
MAGNITUDES TO SUPPORT CONTINUED SUPERCELL POTENTIAL ACROSS THIS
REGION.  PARCELS N OF BOUNDARY WILL BE LIFTED ISENTROPICALLY TO LFC
NEAR WRN BRANCH OF 45-50 KT LLJ...ACCESSING MUCAPE IN 2000-3000 J/KG
RANGE.

..EDWARDS.. 04/25/2011

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

ATTN...WFO...SHV...FWD...OUN...SJT...MAF...

LAT...LON   32349549 31319918 31650108 32380089 33169917 33679809
            33729652 33709510 32979495 32349549

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 24, 7:35 PM CDTMesoscale DiscussionSPCCarson, Gray, Hansford, Hemphill, Hutchinson, Lipscomb and 5 more2 hr
Apr 24, 8:48 PM CDTMesoscale DiscussionSPCBosque, Brown, Callahan, Coleman, Collin, Comanche and 36 more117 min
Apr 24, 11:43 PM CDTSevere Thunderstorm WatchSPCBosque, Bowie, Camp, Cass, Collin, Comanche and 40 more5 hr
Apr 24, 11:58 PM CDTMesoscale DiscussionSPCHemphill, Lipscomb, Ochiltree92 min
Apr 25, 3:29 AM CDTMesoscale DiscussionSPCBosque, Camp, Collin, Dallas, Delta, Denton and 24 more61 min
Apr 25, 4:41 AM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Collin, Dallas, Delta and 21 more7 hr
Apr 25, 7:23 AM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Gregg, Harrison, Marion and 3 more97 min
Apr 25, 10:46 AM CDTMesoscale DiscussionSPCAnderson, Bosque, Bowie, Brazos, Camp, Cass and 42 more59 min
Apr 25, 11:00 AM CDTTornado WatchSPCBosque, Bowie, Camp, Cass, Collin, Cooke and 34 more7 hr
Apr 25, 1:28 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Collin, Cooke, Dallas and 30 more92 min
Apr 25, 2:16 PM CDTMesoscale DiscussionSPCAngelina, Bastrop, Bell, Blanco, Brazos, Burleson and 27 more59 min
Apr 25, 2:41 PM CDTTornado WatchSPCAnderson, Angelina, Bastrop, Bell, Blanco, Bosque and 49 more9 hr
Apr 25, 3:22 PM CDTTornado Watch PDSSPCBowie, Camp, Cass, Franklin, Gregg, Harrison and 7 more8 hr
Apr 25, 5:21 PM CDTMesoscale DiscussionSPCBosque, Delta, Ellis, Henderson, Hill, Hopkins and 7 more54 min
Apr 25, 5:24 PM CDTMesoscale DiscussionSPCArmstrong, Carson, Childress, Collingsworth, Donley, Gray and 3 more66 min
Apr 25, 6:57 PM CDTMesoscale DiscussionSPCAnderson, Angelina, Bell, Blanco, Brazos, Burleson and 22 more2 hr

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.