Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 826

May 20, 201162 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at May 20, 2011, 12:08 PM CDT for 62 counties in Texas. It was in force for 67 min.

The area

The outline as issued.

The facts

Issued
May 20, 2011, 12:08 PM CDT (17:08 UTC)
Expired
May 20, 2011, 1:15 PM CDT
In force
67 min
Issued by
the Storm Prediction Center
All 62 counties

Anderson County, TX, Bandera County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Bosque County, TX, Brazos County, TX, Brown County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Collin County, TX, Comal County, TX, Comanche County, TX, Coryell County, TX, Dallas County, TX, Delta County, TX, Denton County, TX, Ellis County, TX, Erath County, TX, Falls County, TX, Fannin County, TX, Freestone County, TX, Gillespie County, TX, Grayson County, TX, Guadalupe County, TX, Hamilton County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Hood County, TX, Hopkins County, TX, Hunt County, TX, Johnson County, TX, Kaufman County, TX, Kendall County, TX, Kerr County, TX, Lamar County, TX, Lampasas County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Llano County, TX, Madison County, TX, Mason County, TX, McCulloch County, TX, McLennan County, TX, Milam County, TX, Mills County, TX, Navarro County, TX, Palo Pinto County, TX, Parker County, TX, Rains County, TX, Robertson County, TX, Rockwall County, TX, San Saba County, TX, Somervell County, TX, Tarrant County, TX, Travis County, TX, Van Zandt County, TX, Williamson County, TX, Wise County, TX

The radar

The Ft Hood radar (KGRK), 71 km from the middle of the area, began a volume at 17:09 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

Fort Worth, TX (KFWD), launched 12:00Z, 5.1 hours before the alert went out and 172 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 2011-05-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2657 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 2011-05-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 129 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
2657 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
545 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
203 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.0

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
May 19, 7:47 PM CDTMesoscale DiscussionSPCBaylor, Haskell, Knox, Wichita, Wilbarger118 min
May 19, 9:36 PM CDTMesoscale DiscussionSPCBorden, Briscoe, Childress, Coke, Collingsworth, Cottle and 28 more84 min
May 19, 11:39 PM CDTSevere Thunderstorm WatchSPCBaylor, Borden, Childress, Coke, Cottle, Dickens and 19 more6 hr
May 20, 2:58 AM CDTMesoscale DiscussionSPCBaylor, Coke, Fisher, Foard, Glasscock, Haskell and 11 more92 min
May 20, 10:30 AM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Cherokee, Collin and 31 more60 min
May 20, 11:03 AM CDTTornado WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more7 hr
May 20, 12:28 PM CDTSevere Thunderstorm WatchSPCAnderson, Bandera, Bastrop, Bell, Bexar, Blanco and 60 more10 hr
May 20, 1:28 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Franklin, Gregg, Harrison and 8 more62 min
May 20, 4:00 PM CDTMesoscale DiscussionSPCAnderson, Bowie, Camp, Cass, Delta, Franklin and 18 more60 min
May 20, 5:34 PM CDTMesoscale DiscussionSPCAnderson, Bandera, Bastrop, Bell, Bexar, Blanco and 41 more116 min
May 20, 5:56 PM CDTTornado WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 10 more3 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.