Alert archive / Texas / Flash Flood Warnings in 2017

Flash Flood Warning 27, NWS Austin/San Antonio, TX

August 27, 2017Gonzales County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 27, 2017, 11:53 PM CDT for Gonzales County, Texas. It was in force for 6 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 27, 2017, 11:53 PM CDT (04:53 UTC)
Expired: Aug 28, 2017, 5:45 AM CDT
In force: 6 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Flood severity: None

County Gonzales County, TX

The radar

The Austin/San Antonio radar (KEWX), 67 km from the middle of the area, began a volume at 04:52 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 was reported inside it

Time	Report	Where	Remark
Aug 28, 12:02 AM CDT	FLASH FLOOD	5 E Waelder, TX	REPORT OF I-10 MM 655 EASTBOUND AND WESTBOUND LANES CLOSED DUE TO FLOODING.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Corpus Christi, TX (KCRP), launched 00:00Z, 4.9 hours before the alert went out and 203 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: 2 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 588 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 66 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

874 
WGUS54 KEWX 280453
FFWEWX
TXC177-281045-
/O.NEW.KEWX.FF.W.0027.170828T0453Z-170828T1045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
1153 PM CDT SUN AUG 27 2017

The National Weather Service in Austin San Antonio has issued a

* Flash Flood Warning for...
  Gonzales County in south central Texas...

* Until 545 AM CDT

* At 1146 PM CDT, Doppler radar indicated moderate to heavy rain 
  across Gonzales county with rainfall rates of up to 1 inch per 
  hours, especially in the Gonzales to Waelder areas. Rainfall 
  amounts of 10 to 21 inches have fallen due to Harvey. This 
  additional rain will aggravate the flooding. Numerous rivers and 
  streams are out of banks or in flood. Travel is highly 
  discouraged. I-10 has been closed near Waelder. 

* Some locations that will experience flooding include...
  Gonzales, Waelder, Palmeto, Oak Forest, Glaze City, Newtonville,
  Belmont, Nickle, Dilworth, Cost, Dreyer, Little New York, Ottine,
  Thompsonville, Hamon and Monthalia.

Additional rainfall amounts of 2 to 6 inches with isolated 
amounts up to 10 inches are possible in the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 2964 9713 2958 9721 2950 9720 2938 9724
      2928 9739 2951 9774 2965 9762 2963 9759
      2978 9733

$$

CP

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 5:44 AM CDT	Flash Flood Warning	EWX	Fayette	9 hr
Aug 28, 5:54 AM CDT	Areal Flood Advisory	EWX	Bastrop, Caldwell, Gonzales, Lee	3 hr

Nearby

Flash Flood Warnings in Texas, 2017 Every flash flood warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.