Alert archive / Texas / Mesoscale Discussions in 2007
Mesoscale Discussion 577
The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2007, 1:14 AM CDT for 41 counties in Texas. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2007, 1:14 AM CDT (06:14 UTC)
- Expired
- Apr 25, 2007, 2:45 AM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
All 41 counties
Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bee County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Caldwell County, TX, Colorado County, TX, Comal County, TX, DeWitt County, TX, Dimmit County, TX, Duval County, TX, Fayette County, TX, Frio County, TX, Gillespie County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Kinney County, TX, La Salle County, TX, Lampasas County, TX, Lavaca County, TX, Lee County, TX, Live Oak County, TX, Llano County, TX, Mason County, TX, Maverick County, TX, McMullen County, TX, Medina County, TX, Real County, TX, Travis County, TX, Uvalde County, TX, Washington County, TX, Webb County, TX, Williamson County, TX, Wilson County, TX, Zavala County, TX
The radar
The Austin/San Antonio radar (KEWX), 72 km from the middle of the area, began a volume at 06:17 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
Corpus Christi, TX (KCRP), launched 00:00Z, 6.2 hours before the alert went out and 182 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
- 2037 J/kg
- Mixed-layer CIN
- -328 J/kg
- Mixed-layer LCL
- 785 m above ground
- 0-6 km bulk shear
- 51 kt
- 0-1 km storm-relative helicity
- 172 m²/s²
- 0-3 km storm-relative helicity
- 133 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.4
The text
As transmitted, in the capitals the NWS used until 2016.
000 ACUS11 KWNS 250615 SWOMCD SPC MCD 250614 TXZ000-250745- MESOSCALE DISCUSSION 0577 NWS STORM PREDICTION CENTER NORMAN OK 0114 AM CDT WED APR 25 2007 AREAS AFFECTED...TX HILL COUNTRY EWD TO THE MIDDLE AND UPPER TX COAST CONCERNING...TORNADO WATCH 183... VALID 250614Z - 250745Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 183 CONTINUES. POTENTIAL FOR DAMAGING WINDS...LARGE HAIL AND PERHAPS A COUPLE TORNADOES IS FORECAST TO SPREAD EWD THROUGH ERN PORTIONS OF WW 183 THROUGH 07-08Z...PRIOR TO MOVING E OF WW AREA. CONVECTIVE TRENDS WILL BE MONITORED FOR AN ADDITIONAL...DOWNSTREAM WW. AS OF 06Z...REGIONAL RADAR IMAGERY INDICATED A RELATIVELY INTENSE MCS FROM JUST E OF SAT TO NEAR COT...THE MOST INTENSE PORTION OF WHICH WAS SITUATED OVER COMAL...GUADALUPE...AND WILSON COUNTIES WITH A GENERAL MOTION OF 265/40-45 KT. AMBIENT INFLOW AIR MASS REMAINS QUITE MOIST EARLY THIS MORNING WITH DEWPOINTS AROUND 70 F...WHICH COUPLED WITH STEEP MID-LEVEL LAPSE RATES WERE CONTRIBUTING TO MLCAPES OF AROUND 2000 J/KG. WHILE 25/00Z CRP OBSERVED SOUNDING INDICATED THE PRESENCE OF A STRONG CAP AROUND 850 MB...THE COMBINATION OF STRONG ASCENT ALONG LEADING EDGE OF SYSTEM COLD POOL AND LARGER-SCALE FORCING FOR ASCENT ATTENDANT TO UPPER TROUGH OVER WRN TX ARE LIKELY ERODING THIS CAP. AS SUCH...EXPECT ONGOING MCS TO LIKELY CONTINUE THIS MORNING EWD TOWARD THE MIDDLE AND UPPER TX COAST. RELATIVELY STRONG VERTICAL SHEAR OBSERVED ON LOCAL PROFILERS AND RUC FORECAST SOUNDINGS SHOULD CONTINUE TO MAINTAIN AN ORGANIZED SYSTEM WITH THE POTENTIAL FOR EMBEDDED SUPERCELLS CAPABLE OF DAMAGING WINDS...LARGE HAIL AND PERHAPS A TORNADO OR TWO. ..MEAD.. 04/25/2007 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...HGX...FWD...CRP...EWX...BRO...SJT... 31339841 30219631 29119654 28569764 27959784 27819813 27139818 27159972 29130083 30519971
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 24, 7:33 PM CDT | Mesoscale Discussion | SPC | Bowie, Camp, Cass, Collin, Dallas, Delta and 25 more | 117 min |
| Apr 24, 10:07 PM CDT | Mesoscale Discussion | SPC | Anderson, Atascosa, Bandera, Bastrop, Bell, Bexar and 65 more | 83 min |
| Apr 24, 10:35 PM CDT | Tornado Watch | SPC | Anderson, Bell, Bosque, Bowie, Camp, Cass and 37 more | 5 hr |
| Apr 24, 10:53 PM CDT | Tornado Watch | SPC | Atascosa, Bandera, Bastrop, Bexar, Blanco, Burnet and 28 more | 7 hr |
| Apr 24, 11:58 PM CDT | Mesoscale Discussion | SPC | Anderson, Bell, Bowie, Camp, Cass, Cherokee and 20 more | 92 min |
| Apr 25, 1:40 AM CDT | Tornado Watch | SPC | Aransas, Austin, Bee, Brazoria, Brazos, Burleson and 30 more | 7 hr |
| Apr 25, 2:10 AM CDT | Mesoscale Discussion | SPC | Sabine, San Augustine, Shelby | 65 min |
| Apr 25, 4:29 AM CDT | Mesoscale Discussion | SPC | Angelina, Aransas, Austin, Bee, Brazoria, Brazos and 35 more | 91 min |
| Apr 25, 7:36 AM CDT | Mesoscale Discussion | SPC | Aransas, Austin, Bee, Brazoria, Calhoun, Chambers and 28 more | 84 min |
| Apr 25, 9:00 AM CDT | Mesoscale Discussion | SPC | Brazoria, Chambers, Galveston, Hardin, Harris, Jasper and 9 more | 60 min |
| Apr 25, 9:13 AM CDT | Tornado Watch | SPC | Aransas, Brazoria, Calhoun, Chambers, Fort Bend, Galveston and 8 more | 8 hr |
| Apr 25, 3:05 PM CDT | Mesoscale Discussion | SPC | Galveston | 55 min |
| Apr 25, 6:15 PM CDT | Mesoscale Discussion | SPC | Angelina, Nacogdoches, Panola, Polk, San Augustine, Shelby and 2 more | 90 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.