Alert archive / Texas / Severe Thunderstorm Watches in 2007

Severe Thunderstorm Watch 263

May 9, 200718 counties in Texas

The Storm Prediction Center issued this severe thunderstorm watch at May 9, 2007, 7:03 PM CDT for 18 counties in Texas. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2007, 7:03 PM CDT (00:03 UTC)
Expired
May 9, 2007, 11:00 PM CDT
In force
4 hr
Issued by
the Storm Prediction Center
Largest hail expected
1.5 in
Strongest gust expected
60 kt

Counties Bell County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Comal County, TX, Coryell County, TX, Gillespie County, TX, Guadalupe County, TX, Hamilton County, TX, Hays County, TX, Kendall County, TX, Lampasas County, TX, Llano County, TX, McLennan County, TX, Mills County, TX, Travis County, TX, Williamson County, TX, Wilson County, TX

The radar

The Ft Hood radar (KGRK), 115 km from the middle of the area, began a volume at 00:06 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.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
20%
One or more EF2 to EF5 tornadoes
5%
Ten or more severe wind reports
30%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
30%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
70%

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 0.1 hours before the alert went out and 352 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, Corpus Christi, TX at 00:00Z on 2007-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 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, Corpus Christi, TX at 00:00Z on 2007-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
15 J/kg
Mixed-layer CIN
-486 J/kg
Mixed-layer LCL
1188 m above ground
0-6 km bulk shear
50 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
78 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 9:33 PM CDTMesoscale DiscussionSPCWebb, Zapata57 min
May 10, 2:56 PM CDTMesoscale DiscussionSPCAtascosa, Austin, Bastrop, Bee, Bexar, Brazoria and 42 more2 hr
May 10, 5:54 PM CDTSevere Thunderstorm WatchSPCAransas, Atascosa, Austin, Bee, Brazoria, Calhoun and 25 more5 hr

Nearby

Severe Thunderstorm Watches in Texas, 2007Every severe thunderstorm watch 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.