Alert archive / Texas / Mesoscale Discussions in 2011

Mesoscale Discussion 473

April 19, 201130 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 19, 2011, 3:45 PM CDT for 30 counties in Texas. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued
Apr 19, 2011, 3:45 PM CDT (20:45 UTC)
Expired
Apr 19, 2011, 4:45 PM CDT
In force
60 min
Issued by
the Storm Prediction Center
All 30 counties

Bastrop County, TX, Bell County, TX, Bexar County, TX, Blanco County, TX, Bosque County, TX, Burleson County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, Coryell County, TX, Ellis County, TX, Falls County, TX, Freestone County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Henderson County, TX, Hill County, TX, Johnson County, TX, Kendall County, TX, Lampasas County, TX, Lee County, TX, Limestone County, TX, McLennan County, TX, Milam County, TX, Navarro County, TX, Robertson County, TX, Travis County, TX, Williamson County, TX, Wilson County, TX

The radar

The Ft Hood radar (KGRK), 21 km from the middle of the area, began a volume at 20:47 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, 8.8 hours before the alert went out and 252 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 2011-04-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3369 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 2011-04-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 361 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
3369 J/kg
Mixed-layer CIN
-217 J/kg
Mixed-layer LCL
660 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
361 m²/s²
0-3 km storm-relative helicity
398 m²/s²
Significant tornado parameter
0.0
Supercell composite
5.1

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 19, 1:40 PM CDTMesoscale DiscussionSPCCollin, Dallas, Delta, Denton, Ellis, Fannin and 10 more65 min
Apr 19, 2:16 PM CDTTornado WatchSPCBowie, Camp, Cass, Collin, Dallas, Delta and 17 more10 hr
Apr 19, 5:44 PM CDTSevere Thunderstorm WatchSPCAnderson, Bell, Blanco, Bosque, Burnet, Coryell and 19 more4 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.