Alert archive / Texas / Mesoscale Discussions in 2007

Mesoscale Discussion 430

April 3, 20077 counties in Texas

The Storm Prediction Center issued this mesoscale discussion at Apr 3, 2007, 5:10 PM CDT for 7 counties in Texas. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued: Apr 3, 2007, 5:10 PM CDT (22:10 UTC)
Expired: Apr 3, 2007, 7:45 PM CDT
In force: 3 hr
Issued by: the Storm Prediction Center

Counties Bandera County, TX, Blanco County, TX, Gillespie County, TX, Kendall County, TX, Kerr County, TX, Llano County, TX, Real County, TX

The radar

The Austin/San Antonio radar (KEWX), 125 km from the middle of the area, began a volume at 22:12 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.

Severe Thunderstorm Watch 116Apr 3, 5:50 PM CDT

The nearest sounding before it

Del Rio, TX (KDRT), launched 12:00Z, 10.2 hours before the alert went out and 197 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1663 J/kg
Mixed-layer CIN: -318 J/kg
Mixed-layer LCL: 1070 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 71 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 032210
SWOMCD
SPC MCD 032210 
TXZ000-040045-

MESOSCALE DISCUSSION 0430
NWS STORM PREDICTION CENTER NORMAN OK
0510 PM CDT TUE APR 03 2007

AREAS AFFECTED...SCENTRAL TX

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 032210Z - 040045Z

ISOLATED SVR STORMS ARE EXPECTED TO DEVELOP OVER THE EDWARDS PLATEAU
AREA OF SCENTRAL TX IN THE NEXT 1-2 HRS. AREA WILL BE MONITORED FOR
A POSSIBLE WW. 

VIS SAT IMAGERY SHOWS TOWERING CU OVER THE EDWARDS PLATEAU THAT HAS
FORMED ALONG THE DRYLINE. AIRMASS DOWNSTREAM OF THIS ACTIVITY WAS
EXTREMELY UNSTABLE WITH MLCAPES AROUND 3500 J/KG. DESPITE LIMITED
VERTICAL SHEAR...VERY LARGE HAIL AND POSSIBLE DMGG WINDS ARE
EXPECTED WITHIN THE NEXT FEW HRS AS THIS ACTIVITY INCREASES. AREAL
COVERAGE OF SVR REMAINS UNCERTAIN GIVEN LACK OF LARGER SCALE
FORCING...BUT A WW MAY BE NEEDED IF TRENDS IN THE POTENTIAL
DEVELOPMENT AREA INCREASE OR ACTIVITY IS WITHIN RELATIVE CLOSE
DISTANCE TO EXPECTED SVR TSTMS OVER NCENTRAL AND CENTRAL TX /REF MCD
429/.

..CROSBIE.. 04/03/2007

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

ATTN...WFO...EWX...SJT...

30889884 30609931 30369955 30149979 29609986 29499918
30259829 30729836

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 3, 11:29 AM CDT	Mesoscale Discussion	SPC	Hardin, Jasper, Newton, Orange	2 hr
Apr 3, 2:17 PM CDT	Mesoscale Discussion	SPC	Bowie, Camp, Cass, Collin, Dallas, Delta and 19 more	118 min
Apr 3, 4:23 PM CDT	Mesoscale Discussion	SPC	Bosque, Brown, Comanche, Erath, Hamilton, Hood and 5 more	3 hr
Apr 3, 5:47 PM CDT	Severe Thunderstorm Watch	SPC	Bandera, Bell, Blanco, Bosque, Bowie, Burnet and 49 more	7 hr

Nearby

Mesoscale Discussions in Texas, 2007 Every 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.