Alert archive / Texas / Flash Flood Watches in 2009

Flash Flood Watch 8, NWS Austin/San Antonio, TX

October 8, 200930 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood watch at Oct 8, 2009, 3:34 AM CDT for 30 counties in Texas. It took effect at Oct 8, 2009, 7:00 PM CDT. It was in force for 16 hr.

The area

The counties it named.

The facts

Issued: Oct 8, 2009, 3:34 AM CDT (08:34 UTC)
In effect from: Oct 8, 2009, 7:00 PM CDT
Expired: Oct 9, 2009, 11:27 AM CDT
In force: 16 hr
Issued by: NWS Austin/San Antonio, TX
Flood severity: None

All 30 counties

Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Burnet County, TX, Caldwell County, TX, Comal County, TX, DeWitt County, TX, Edwards 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, Lavaca County, TX, Lee County, TX, Llano County, TX, Medina County, TX, Real County, TX, Travis County, TX, Uvalde County, TX, Val Verde County, TX, Williamson County, TX, Wilson County, TX

The radar

The Austin/San Antonio radar (KEWX), 44 km from the middle of the area, began a volume at 08:37 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 nearest sounding before it

Del Rio, TX (KDRT), launched 00:00Z, 8.6 hours before the alert went out and 233 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: 1079 J/kg
Mixed-layer CIN: -191 J/kg
Mixed-layer LCL: 1648 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 199 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.6

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Austin/San Antonio, TX wrote its last area forecast discussion before this flash flood watch went out at Oct 7, 11:56 PM CDT, 3 hours 38 minutes earlier.

Area forecast discussion, Oct 7, 11:56 PM CDT, 3 hours 38 minutes before

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Hazardous weather outlook, Oct 7, 5:21 AM CDT, 22 hours 13 minutes before

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The office that day

Everything else NWS Austin/San Antonio, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 8, 5:55 PM CDT	Severe Thunderstorm Warning	EWX	Val Verde	65 min
Oct 8, 6:52 PM CDT	Tornado Warning	EWX	Val Verde	53 min

Nearby

Flash Flood Watches in Texas, 2009 Every flash flood watch in 2009

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.