Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 621

April 29, 200730 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2007, 8:35 PM CDT for 30 counties in Texas. It was in force for 115 min.

The area

The outline as issued.

The facts

Issued
Apr 29, 2007, 8:35 PM CDT (01:35 UTC)
Expired
Apr 29, 2007, 10:30 PM CDT
In force
115 min
Issued by
the Storm Prediction Center
All 30 counties

Baylor County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Concho County, TX, Ector County, TX, Fisher County, TX, Foard County, TX, Glasscock County, TX, Hardeman County, TX, Haskell County, TX, Howard County, TX, Irion County, TX, Jones County, TX, Kent County, TX, King County, TX, Knox County, TX, Menard County, TX, Midland County, TX, Mitchell County, TX, Nolan County, TX, Runnels County, TX, Scurry County, TX, Shackelford County, TX, Sterling County, TX, Stonewall County, TX, Taylor County, TX, Throckmorton County, TX, Tom Green County, TX, Wilbarger County, TX

The radar

The Dyess AFB radar (KDYX), 95 km from the middle of the area, began a volume at 01:36 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

Midland Regional, TX (KMAF), launched 00:00Z, 1.6 hours before the alert went out and 190 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, Midland Regional, TX at 00:00Z on 2007-04-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 218 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Midland Regional, TX at 00:00Z on 2007-04-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 151 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
218 J/kg
Mixed-layer CIN
-145 J/kg
Mixed-layer LCL
895 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
151 m²/s²
0-3 km storm-relative helicity
257 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.5

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
ACUS11 KWNS 300135
SWOMCD
SPC MCD 300135 
TXZ000-OKZ000-300330-

MESOSCALE DISCUSSION 0621
NWS STORM PREDICTION CENTER NORMAN OK
0835 PM CDT SUN APR 29 2007

AREAS AFFECTED...NWRN TX

CONCERNING...SEVERE THUNDERSTORM WATCH 199...

VALID 300135Z - 300330Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 199
CONTINUES.

WIDESPREAD DEEP CONVECTION CONTINUES ALONG AND NORTH OF WELL-DEFINED
CONVECTIVE OUTFLOW BOUNDARY FROM NEAR ABI SWWD TO SJT AND THEN WWD
TO FST. MESOSCALE LIFT ACROSS THE BOUNDARY COUPLED WITH LARGE SCALE
ASCENT WITHIN DIFFLUENT FLOW AHEAD OF UPPER LOW WILL MAINTAIN
ORGANIZED MULTICELLULAR ACTIVITY. ONE WELL ESTABLISHED BOWING LINE
SEGMENT...CURRENTLY ENTERING WRN REAGAN COUNTY IN TORNADO WATCH
200...SHOULD CONTINUE TO MOVE EAST INTO SRN PARTS OF SEVERE TSTM
WATCH 199 IN THE NEXT HOUR. THIS ACTIVITY APPEARS FAVORABLY ORIENTED
TO THE OUTFLOW BOUNDARY TO MAINTAIN STRONG LOW LEVEL INFLOW AND
SHEAR. UNSTABLE AIR MASS SOUTH AND EAST OF THIS CONVECTION REMAINS
UNPERTURBED SO SEVERE POTENTIAL ACROSS SRN PARTS OF WATCH 199 SHOULD
CONTINUE.

DESPITE MODEST LARGE SCALE SUPPORT FOR UPWARD MOTION OVER NWRN
TX...STORMS IN THIS REGION ARE MORE REMOVED FROM UNSTABLE INFLOW.
EXPECT THAT NRN PARTS OF WATCH 199 WILL BEGIN TO BE CLEARED OVER THE
NEXT HOUR.

..CARBIN.. 04/30/2007

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...FWD...OUN...SJT...LUB...MAF...

30739946 30710011 31110013 31080124 31680128 31620274
32100278 32090163 32530165 32480111 32950119 32970107
33400106 33360049 33840052 33810001 34559998 34399968
34259923 34169896 32979894 32959910 32109909 32089922
31469918 31419940 31539957 30959961 30949947

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 29, 7:25 PM CDTMesoscale DiscussionSPCBrewster, Crane, Crockett, Culberson, Jeff Davis, Loving and 11 more65 min
Apr 29, 7:48 PM CDTTornado WatchSPCBandera, Brewster, Crane, Crockett, Dimmit, Edwards and 18 more7 hr
Apr 29, 10:42 PM CDTMesoscale DiscussionSPCBandera, Brewster, Crane, Crockett, Dimmit, Edwards and 18 more63 min
Apr 30, 2:10 AM CDTMesoscale DiscussionSPCBandera, Crockett, Dimmit, Edwards, Frio, Kerr and 12 more95 min
Apr 30, 2:47 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 10 more3 hr
Apr 30, 2:51 AM CDTSevere Thunderstorm WatchSPCBandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 9 more5 hr
Apr 30, 4:46 AM CDTMesoscale DiscussionSPCBandera, Blanco, Burnet, Edwards, Gillespie, Kendall and 9 more119 min
Apr 30, 12:37 PM CDTMesoscale DiscussionSPCAtascosa, Bastrop, Bee, Caldwell, DeWitt, Dimmit and 15 more83 min
Apr 30, 1:22 PM CDTMesoscale DiscussionSPCCamp, Collin, Dallas, Delta, Fannin, Franklin and 14 more113 min
Apr 30, 1:26 PM CDTSevere Thunderstorm WatchSPCAustin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 10 more7 hr
Apr 30, 3:01 PM CDTTornado WatchSPCDimmit, Duval, Frio, Jim Wells, La Salle, Live Oak and 4 more7 hr
Apr 30, 3:23 PM CDTMesoscale DiscussionSPCGrimes, Harris, Houston, Leon, Liberty, Madison and 4 more97 min
Apr 30, 5:38 PM CDTMesoscale DiscussionSPCArcher, Armstrong, Baylor, Borden, Briscoe, Callahan and 42 more2 hr
Apr 30, 6:18 PM CDTMesoscale DiscussionSPCDimmit, Duval, Frio, Jim Wells, La Salle, Live Oak and 4 more57 min
Apr 30, 6:37 PM CDTMesoscale DiscussionSPCAustin, Brazoria, Colorado, DeWitt, Fayette, Fort Bend and 10 more83 min

Nearby

Mesoscale Discussions in Texas, 2007Every mesoscale discussion in 2007

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.