Alert archive / Texas / Flash Flood Watches in 2012

Flash Flood Watch 4, NWS Houston/Galveston, TX

May 10, 201223 counties in Texas

NWS Houston/Galveston, TX issued this flash flood watch at May 10, 2012, 3:08 PM CDT for 23 counties in Texas. It took effect at May 11, 2012, 1:00 AM CDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued: May 10, 2012, 3:08 PM CDT (20:08 UTC)
In effect from: May 11, 2012, 1:00 AM CDT
Expired: May 11, 2012, 7:17 AM CDT
In force: 6 hr
Issued by: NWS Houston/Galveston, TX
Flood severity: None

All 23 counties

Austin County, TX, Brazoria County, TX, Brazos County, TX, Burleson County, TX, Chambers County, TX, Colorado County, TX, Fort Bend County, TX, Galveston County, TX, Grimes County, TX, Harris County, TX, Houston County, TX, Jackson County, TX, Liberty County, TX, Madison County, TX, Matagorda County, TX, Montgomery County, TX, Polk County, TX, San Jacinto County, TX, Trinity County, TX, Walker County, TX, Waller County, TX, Washington County, TX, Wharton County, TX

The radar

The Houston radar (KHGX), 91 km from the middle of the area, began a volume at 20:09 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

Lake Charles Mun, LA (KLCH), launched 12:00Z, 8.1 hours before the alert went out and 242 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1616 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -95 m²/s²
0-3 km storm-relative helicity: 7 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

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 Houston/Galveston, TX wrote its last area forecast discussion before this flash flood watch went out at May 10, 12:36 PM CDT, 2 hours 32 minutes earlier.

Area forecast discussion, May 10, 12:36 PM CDT, 2 hours 32 minutes before

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Hazardous weather outlook, May 10, 6:05 AM CDT, 9 hours 3 minutes before

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The office that day

Everything else NWS Houston/Galveston, TX issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 10, 6:37 PM CDT	Special Marine Warning	HGX		83 min
May 10, 6:44 PM CDT	Special Weather Statement	HGX	Austin	61 min

Nearby

Flash Flood Watches in Texas, 2012 Every flash flood watch in 2012

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.