Alert archive / Texas / Mesoscale Discussions in 2009

Mesoscale Discussion 600

April 27, 200925 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 27, 2009, 11:42 AM CDT for 25 counties in Texas. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
Apr 27, 2009, 11:42 AM CDT (16:42 UTC)
Expired
Apr 27, 2009, 12:45 PM CDT
In force
63 min
Issued by
the Storm Prediction Center
All 25 counties

Anderson County, TX, Bastrop County, TX, Bell County, TX, Blanco County, TX, Brazos County, TX, Burleson County, TX, Burnet County, TX, Falls County, TX, Freestone County, TX, Gillespie County, TX, Grimes County, TX, Hays County, TX, Henderson County, TX, Lee County, TX, Leon County, TX, Limestone County, TX, Madison County, TX, Milam County, TX, Robertson County, TX, Smith County, TX, Travis County, TX, Van Zandt County, TX, Walker County, TX, Washington County, TX, Williamson County, TX

The radar

The Ft Hood radar (KGRK), 30 km from the middle of the area, began a volume at 16:46 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 nearest sounding before it

Fort Worth, TX (KFWD), launched 12:00Z, 4.7 hours before the alert went out and 205 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 2009-04-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2160 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 12:00Z on 2009-04-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 79 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
2160 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
513 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
79 m²/s²
0-3 km storm-relative helicity
315 m²/s²
Significant tornado parameter
0.0
Supercell composite
6.5

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 26, 8:04 PM CDTTornado WatchSPCBlanco, Brown, Burnet, Callahan, Coke, Coleman and 30 more7 hr
Apr 26, 8:42 PM CDTMesoscale DiscussionSPCArcher, Baylor, Childress, Clay, Collingsworth, Cottle and 14 more2 hr
Apr 26, 10:46 PM CDTMesoscale DiscussionSPCBlanco, Brown, Callahan, Coke, Coleman, Concho and 22 more119 min
Apr 27, 1:49 AM CDTMesoscale DiscussionSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 24 more86 min
Apr 27, 2:44 AM CDTSevere Thunderstorm WatchSPCBrown, Callahan, Coke, Coleman, Concho, Crockett and 23 more7 hr
Apr 27, 5:36 AM CDTMesoscale DiscussionSPCBosque, Brown, Coke, Comanche, Concho, Coryell and 17 more84 min
Apr 27, 6:08 AM CDTTornado WatchSPCAnderson, Bastrop, Bell, Blanco, Bosque, Brazos and 33 more7 hr
Apr 27, 7:43 AM CDTMesoscale DiscussionSPCCoke, Concho, Crockett, Irion, Kimble, McCulloch and 8 more92 min
Apr 27, 7:55 AM CDTSevere Thunderstorm WatchSPCBandera, Bexar, Comal, Edwards, Frio, Guadalupe and 9 more5 hr
Apr 27, 8:59 AM CDTMesoscale DiscussionSPCAnderson, Angelina, Bell, Brazos, Burleson, Burnet and 38 more91 min
Apr 27, 9:28 AM CDTSevere Thunderstorm WatchSPCBowie, Camp, Cass, Cherokee, Franklin, Gregg and 12 more12 hr
Apr 27, 12:00 PM CDTMesoscale DiscussionSPCAtascosa, Bandera, Bexar, Comal, Edwards, Kendall and 6 more60 min
Apr 27, 1:14 PM CDTMesoscale DiscussionSPCBowie, Camp, Cass, Gregg, Harrison, Marion and 8 more91 min
Apr 27, 2:24 PM CDTMesoscale DiscussionSPCAngelina, Bowie, Cass, Cherokee, Gregg, Harrison and 10 more66 min
Apr 27, 2:57 PM CDTSevere Thunderstorm WatchSPCBowie, Cass, Harrison, Marion, Panola, Shelby6 hr
Apr 27, 3:50 PM CDTMesoscale DiscussionSPCAransas, Austin, Bee, Brazoria, Calhoun, Chambers and 20 more85 min
Apr 27, 3:58 PM CDTTornado WatchSPCBrazoria, Calhoun, Chambers, Colorado, DeWitt, Fort Bend and 10 more5 hr
Apr 27, 5:59 PM CDTMesoscale DiscussionSPCBorden, Dawson, Fisher, Garza, Kent, Lynn and 4 more2 hr
Apr 27, 6:30 PM CDTMesoscale DiscussionSPCAransas, Brazoria, Calhoun, Chambers, Galveston, Hardin and 4 more2 hr

Nearby

Mesoscale Discussions in Texas, 2009Every mesoscale discussion in 2009

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.