Alert archive / Texas / Mesoscale Discussions in 2004

Mesoscale Discussion 451

April 23, 200424 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 23, 2004, 2:41 PM CDT for 24 counties in Texas. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 23, 2004, 2:41 PM CDT (19:41 UTC)
Expired
Apr 23, 2004, 4:45 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 24 counties

Baylor County, TX, Callahan County, TX, Coke County, TX, Coleman County, TX, Concho County, TX, Fisher County, TX, Foard County, TX, Hardeman County, TX, Haskell County, TX, Irion County, TX, Jones County, TX, King County, TX, Knox County, TX, Mitchell County, TX, Nolan County, TX, Runnels County, TX, Schleicher 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Midland Regional, TX (KMAF), launched 12:00Z, 7.7 hours before the alert went out and 189 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 12:00Z on 2004-04-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 316 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, Midland Regional, TX at 12:00Z on 2004-04-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 92 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
316 J/kg
Mixed-layer CIN
-273 J/kg
Mixed-layer LCL
1706 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
92 m²/s²
0-3 km storm-relative helicity
194 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.

303 
ACUS11 KWNS 231941
SWOMCD
SPC MCD 231941 
TXZ000-OKZ000-232145-

MESOSCALE DISCUSSION 0451
NWS STORM PREDICTION CENTER NORMAN OK
0241 PM CDT FRI APR 23 2004

AREAS AFFECTED...WRN OK INTO W CNTRL TX

CONCERNING...TORNADO WATCH 109...

VALID 231941Z - 232145Z

CONTINUE WW.

STRONG MID-LEVEL FORCING FOR UPWARD VERTICAL MOTION CONTINUES TO
SPREAD NORTHEASTWARD IN CYCLONIC ARC OUT OF THE SOUTHERN HIGH
PLAINS.  THIS FORCING CONTINUES TO PROVIDE SUPPORT FOR INCREASING
CONVECTIVE DEVELOPMENT FROM AREAS SOUTHEAST OF GAGE OK INTO
NORTHWEST TX...NEAR/NORTHWEST OF ABILENE.  SURFACE COLD FRONT IS
NOSING SOUTHWARD INTO THE TEXAS SOUTH PLAINS...WITH AREA OF ENHANCED
CONVERGENCE NEAR DRY LINE INTERSECTION TO THE NORTHWEST OF ABILENE. 
THIS APPEARS LIKELY TO REMAIN FOCUS FOR MOST INTENSE SURFACE BASED
DEVELOPMENT NEXT COUPLE OF HOURS..AND WILL DEVELOP SLOWLY SOUTHWARD.
 

WITH MEAN MIXED LAYER CAPE IN EXCESS OF 2000 J/KG...VERTICAL SHEAR
PROFILES WILL REMAIN FAVORABLE FOR THE DEVELOPMENT OF SUPERCELLS
WITH VERY LARGE HAIL.  THOUGH TENDENCY MAY BE FOR COLD FRONT TO
UNDERCUT CONVECTION...BRIEF FORMATION OF TORNADOES IS POSSIBLE
BEFORE CELLS LIFT NORTH OF BOUNDARY.  NORTH/SOUTH LINE OF CONVECTION
LIKELY WILL CONTINUE TO EVOLVE ALONG/JUST NORTH OF COLD FRONT AS
FRONT ADVANCES TOWARD THE BIG BEND AREA LATE THIS AFTERNOON AND
EVENING.  ACTIVITY WILL BE SLOW TO SHIFT EASTWARD... AND THREAT FOR
HEAVY RAIN WILL INCREASE.

..KERR.. 04/23/2004

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

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

31380145 32700090 34549970 34229871 32639887 31609945
30890020 30710125

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 22, 8:00 PM CDTMesoscale DiscussionSPCCooke, Grayson, Jack60 min
Apr 22, 9:06 PM CDTMesoscale DiscussionSPCMontague24 min
Apr 22, 11:47 PM CDTMesoscale DiscussionSPCHansford, Hemphill, Hutchinson, Lipscomb, Ochiltree, Roberts58 min
Apr 23, 10:10 AM CDTMesoscale DiscussionSPCChildress, Collingsworth, Cottle, Crosby, Dickens, Foard and 9 more3 hr
Apr 23, 12:15 PM CDTTornado WatchSPCArcher, Baylor, Brown, Callahan, Clay, Coke and 33 more6 hr
Apr 23, 4:40 PM CDTMesoscale DiscussionSPCArcher, Baylor, Brown, Callahan, Clay, Coke and 30 more65 min
Apr 23, 5:30 PM CDTSevere Thunderstorm WatchSPCArcher, Baylor, Brown, Callahan, Clay, Coke and 28 more7 hr

Nearby

Mesoscale Discussions in Texas, 2004Every mesoscale discussion in 2004

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.