Alert archive / Texas / Mesoscale Discussions in 2003
Mesoscale Discussion 620
The Storm Prediction Center issued this mesoscale discussion at Apr 29, 2003, 1:38 PM CDT for 37 counties in Texas. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 29, 2003, 1:38 PM CDT (18:38 UTC)
- Expired
- Apr 29, 2003, 4:45 PM CDT
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
All 37 counties
Borden County, TX, Briscoe County, TX, Childress County, TX, Coke County, TX, Cottle County, TX, Crockett County, TX, Crosby County, TX, Dawson County, TX, Dickens County, TX, Fisher County, TX, Floyd County, TX, Garza County, TX, Glasscock County, TX, Hale County, TX, Hall County, TX, Howard County, TX, Irion County, TX, Kent County, TX, King County, TX, Lubbock County, TX, Lynn County, TX, Martin County, TX, Midland County, TX, Mitchell County, TX, Motley County, TX, Nolan County, TX, Reagan County, TX, Schleicher County, TX, Scurry County, TX, Sterling County, TX, Stonewall County, TX, Swisher County, TX, Terrell County, TX, Terry County, TX, Tom Green County, TX, Upton County, TX, Val Verde County, TX
The radar
The Midland/Odessa radar (KMAF), 77 km from the middle of the area, began a volume at 18:40 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
Midland Regional, TX (KMAF), launched 12:00Z, 6.6 hours before the alert went out and 78 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.
- Mixed-layer CAPE
- 893 J/kg
- Mixed-layer CIN
- -313 J/kg
- Mixed-layer LCL
- 1124 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 131 m²/s²
- 0-3 km storm-relative helicity
- 195 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted, in the capitals the NWS used until 2016.
676 ACUS11 KWNS 291838 SWOMCD SPC MCD 291838 TXZ000-292145- MESOSCALE DISCUSSION 0620 NWS STORM PREDICTION CENTER NORMAN OK 0138 PM CDT TUE APR 29 2003 AREAS AFFECTED...SOUTHWESTERN TEXAS/PANHANDLE CONCERNING...SEVERE THUNDERSTORM POTENTIAL VALID 291838Z - 292145Z SRN PANHANDLE AND SWRN TEXAS BEING MONITORED FOR A SEVERE THUNDERSTORMS WATCH. DRY LINE IS MIXING GRADUALLY EWD INTO WRN PORTION OF SRN TX PANHANDLE. E OF DRY LINE AIRMASS HAS BECOME VERY UNSTABLE WITH MUCAPES TO 4000 J/KG. WHILE DEEP LAYER SHEAR IS RELATIVELY WEAK...THE NEAR ADIABATIC LAPSE RATES COUPLED WITH INSTABILITY SUPPORTS RAPID DEVELOPMENT OF SEVERE THUNDERSTORMS NEXT COUPLE OF HOURS. AREA OF SURFACE BASED CONVECTION NOTED ON 1815Z VISIBLE IMAGERY W OF LBB APPEARS TO BE FIRST INDICATION OF DEVELOPMENT. ..HALES.. 04/29/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OUN...EWX...SJT...LUB...AMA...MAF... 31880234 33320240 34340194 34910152 34720066 34500003 32650005 31220035 29590082 29740177 29890237 30730242
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 7:22 PM CDT | Mesoscale Discussion | SPC | Armstrong, Borden, Briscoe, Carson, Castro, Coke and 29 more | 53 min |
| Apr 28, 9:20 PM CDT | Mesoscale Discussion | SPC | Bell, Blanco, Bosque, Brown, Burnet, Caldwell and 38 more | 85 min |
| Apr 29, 2:30 PM CDT | Severe Thunderstorm Watch | SPC | Armstrong, Borden, Briscoe, Carson, Childress, Coke and 32 more | 6 hr |
| Apr 29, 5:50 PM CDT | Mesoscale Discussion | SPC | Armstrong, Borden, Briscoe, Childress, Coke, Collingsworth and 40 more | 85 min |
| Apr 29, 6:25 PM CDT | Severe Thunderstorm Watch | SPC | Archer, Baylor, Borden, Callahan, Childress, Coke and 42 more | 6 hr |
Nearby
Mesoscale Discussions in Texas, 2003Every mesoscale discussion in 2003
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.