Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 550

April 24, 201119 counties in Oklahoma; 43 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 24, 2011, 1:13 PM CDT for 19 counties in Oklahoma; 43 counties in Texas. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Apr 24, 2011, 1:13 PM CDT (18:13 UTC)
Expired
Apr 24, 2011, 2:45 PM CDT
In force
92 min
Issued by
the Storm Prediction Center
All 62 counties

Atoka County, OK, Bryan County, OK, Carter County, OK, Choctaw County, OK, Coal County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Hughes County, OK, Jefferson County, OK, Johnston County, OK, Love County, OK, Marshall County, OK, McClain County, OK, Murray County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Stephens County, OK, Archer County, TX, Baylor County, TX, Brown County, TX, Callahan County, TX, Clay 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, Erath County, TX, Fannin County, TX, Fisher County, TX, Grayson County, TX, Haskell County, TX, Hood County, TX, Hunt County, TX, Jack County, TX, Johnson County, TX, Jones County, TX, Knox County, TX, Lamar County, TX, Montague County, TX, Nolan County, TX, Palo Pinto County, TX, Parker County, TX, Rockwall County, TX, Runnels County, TX, Shackelford County, TX, Somervell County, TX, Stephens County, TX, Sterling County, TX, Tarrant County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wichita County, TX, Wise County, TX, Young County, TX

The radar

The Dallas/Ft Worth radar (KFWS), 92 km from the middle of the area, began a volume at 18:13 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

Fort Worth, TX (KFWD), launched 12:00Z, 6.2 hours before the alert went out and 75 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 12:00Z on 2011-04-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1821 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, Fort Worth, TX at 12:00Z on 2011-04-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 131 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
1821 J/kg
Mixed-layer CIN
-95 J/kg
Mixed-layer LCL
577 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
131 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.7
Supercell composite
5.6

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
Apr 23, 7:04 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Carter, Choctaw, Coal, Jefferson and 9 more86 min
Apr 23, 9:08 PM CDTMesoscale DiscussionSPCAdair, Canadian, Cherokee, Cleveland, Craig, Creek and 26 more97 min
Apr 23, 9:53 PM CDTSevere Thunderstorm WatchSPCAdair, Atoka, Bryan, Caddo, Canadian, Carter and 47 more7 hr
Apr 23, 10:40 PM CDTMesoscale DiscussionSPCAdair95 min
Apr 24, 2:02 AM CDTMesoscale DiscussionSPCAtoka, Bryan, Caddo, Canadian, Carter, Cherokee and 42 more88 min
Apr 24, 4:17 AM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Cherokee, Cleveland, Coal and 29 more28 min
Apr 24, 2:28 PM CDTSevere Thunderstorm WatchSPCAdair, Atoka, Bryan, Carter, Cherokee, Choctaw and 31 more7 hr
Apr 24, 5:34 PM CDTMesoscale DiscussionSPCAdair, Atoka, Bryan, Choctaw, Coal, Haskell and 11 more26 min
Apr 24, 5:36 PM CDTTornado WatchSPCAtoka, Bryan, Choctaw, Coal, Haskell, Johnston and 7 more7 hr
Apr 24, 6:23 PM CDTMesoscale DiscussionSPCAtoka, Bryan, Choctaw, Latimer, LeFlore, McCurtain and 2 more2 hr
Apr 24, 2:19 PM CDTSevere Thunderstorm WatchSPCBrown, Callahan, Coke, Coleman, Comanche, Concho and 17 more3 hr
Apr 24, 4:51 PM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Comanche, Concho and 19 more24 min
Apr 24, 4:54 PM CDTTornado WatchSPCBrown, Callahan, Coke, Coleman, Collin, Comanche and 33 more7 hr
Apr 24, 5:22 PM CDTMesoscale DiscussionSPCCrockett, Edwards, Irion, Kinney, Maverick, Menard and 4 more83 min

Nearby

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