Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 498

April 20, 201111 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 20, 2011, 7:00 PM CDT for 11 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Apr 20, 2011, 7:00 PM CDT (00:00 UTC)
Expired
Apr 20, 2011, 8:00 PM CDT
In force
60 min
Issued by
the Storm Prediction Center

Counties Archer County, TX, Callahan County, TX, Coleman County, TX, Eastland County, TX, Jack County, TX, Palo Pinto County, TX, Shackelford County, TX, Stephens County, TX, Taylor County, TX, Throckmorton County, TX, Young County, TX

The nearest sounding before it

Fort Worth, TX (KFWD), launched 00:00Z, 0.0 hours before the alert went out and 150 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 2011-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 23 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 00:00Z on 2011-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 213 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
23 J/kg
Mixed-layer CIN
-713 J/kg
Mixed-layer LCL
482 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
213 m²/s²
0-3 km storm-relative helicity
251 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.4

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 21, 2:19 PM CDTMesoscale DiscussionSPCCoke, Crane, Crockett, Fisher, Glasscock, Howard and 16 more56 min
Apr 21, 3:03 PM CDTSevere Thunderstorm WatchSPCBorden, Brewster, Brown, Callahan, Coke, Coleman and 23 more7 hr
Apr 21, 3:23 PM CDTMesoscale DiscussionSPCCamp, Collin, Cooke, Dallas, Delta, Denton and 25 more67 min
Apr 21, 5:10 PM CDTMesoscale DiscussionSPCBorden, Brewster, Coke, Crockett, Fisher, Glasscock and 21 more65 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.