Alert archive / Texas / Flash Flood Warnings in 2018

Flash Flood Warning 36, NWS Austin/San Antonio, TX

September 21, 2018Williamson County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Sep 21, 2018, 11:37 PM CDT for Williamson County, Texas. It was in force for 5 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
Sep 21, 2018, 11:37 PM CDT (04:37 UTC)
Expired
Sep 22, 2018, 4:30 AM CDT
In force
5 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

County Williamson County, TX

The radar

The Ft Hood radar (KGRK), 27 km from the middle of the area, began a volume at 04:40 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

TimeReportWhereRemark
Sep 22, 1:37 AM CDTFLASH FLOODCoupland, TXTHE TAYLOR POLICE DEPARTMENT RELAYED REPORTS OF A FEW ROADS CLOSED IN TAYLOR AS WELL AS ROADS CLOSED DUE TO HIGH WATER AROUND THE COUPLAND AREA.

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, 4.6 hours before the alert went out and 305 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 2018-09-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1928 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 2018-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 square meters per square second.1939Sfc1 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
1928 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1044 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
53 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

512 
WGUS54 KEWX 220437
FFWEWX
TXC491-220730-
/O.NEW.KEWX.FF.W.0036.180922T0437Z-180922T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
1137 PM CDT FRI SEP 21 2018

The National Weather Service in Austin San Antonio has issued a

* Flash Flood Warning for...
  Southeastern Williamson County in south central Texas...

* Until 230 AM CDT

* At 1135 PM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 4 inches of rain 
  has already fallen in a short amount of time across the warned 
  area, with isolated pockets of over 6 inches estimated east of 
  Coupland. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Taylor, Hutto, Thrall, Coupland, Rices Crossing, Noack and
  Beyarsville.

Additional rainfall amounts of 1 to 3 inches are possible over 
portions of 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.

&&

LAT...LON 3047 9716 3045 9717 3040 9733 3042 9738
      3044 9740 3044 9742 3046 9744 3046 9746
      3049 9751 3048 9753 3048 9755 3050 9757
      3054 9757 3063 9723

$$

RUNYEN
2 follow-up statements
069 
WGUS74 KEWX 220607
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
107 AM CDT SAT SEP 22 2018

TXC491-220730-
/O.CON.KEWX.FF.W.0036.000000T0000Z-180922T0730Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Williamson TX-
107 AM CDT SAT SEP 22 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM CDT FOR
SOUTHEASTERN WILLIAMSON COUNTY...

At 106 AM CDT, Doppler radar indicated a widespread 3 to 5 inches of 
rain occurred across the warned area, with pockets in excess of 6 
inches. Flash flooding is already occurring.

Some locations that will experience flooding include...
Taylor, Hutto, Thrall, Coupland, Rices Crossing, Noack and
Beyarsville.

This includes the following streams and drainages...Bull Branch,
Cottonwood Creek, Little Dry Brushy Creek, Cross Creek, Brushy Creek,
Battleground Creek, Turkey Creek, Holynok Creek, Middle Yegua Creek,
Houghton Branch, Mustang Creek, Little Sandy Creek and Dry Brushy
Creek.

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.

&&

LAT...LON 3047 9716 3045 9717 3040 9733 3042 9738
      3044 9740 3044 9742 3046 9744 3046 9746
      3049 9751 3048 9753 3048 9755 3050 9757
      3054 9757 3063 9723

$$

RUNYEN
824 
WGUS54 KEWX 220719
FFWEWX
TXC491-220930-
/O.EXT.KEWX.FF.W.0036.000000T0000Z-180922T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
219 AM CDT SAT SEP 22 2018

The National Weather Service in Austin San Antonio has extended the

* Flash Flood Warning for...
  Southeastern Williamson County in south central Texas...

* Until 430 AM CDT

* At 216 AM CDT, local law enforcement reported some road closures 
  due to flooding around the Taylor and Coupland areas. Earlier 
  thunderstorms produced a widespread 3 to 5 inches of rain across 
  the warned area, with pockets in excess of 6 inches. Additional 
  thunderstorms could produce another 1/2 to 1 inch of rainfall on 
  top of what has already occurred. Dangerous flash flooding is 
  already occurring.

* Some locations that will experience flooding include...
  Taylor, Hutto, Thrall, Coupland, Rices Crossing, Noack and
  Beyarsville.

This includes the following streams and drainages...Bull Branch,
Cottonwood Creek, Little Dry Brushy Creek, Cross Creek, Brushy Creek,
Battleground Creek, Turkey Creek, Holynok Creek, Middle Yegua Creek,
Houghton Branch, Mustang Creek, Little Sandy Creek and Dry Brushy
Creek.

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.

&&

LAT...LON 3047 9716 3045 9717 3040 9733 3042 9738
      3044 9740 3044 9742 3046 9744 3046 9746
      3049 9751 3048 9753 3048 9755 3050 9757
      3054 9757 3063 9723

$$

RUNYEN

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 21, 7:04 PM CDTSpecial Weather StatementEWXLee41 min
Sep 21, 9:39 PM CDTSpecial Weather StatementEWXLee51 min
Sep 21, 10:04 PM CDTAreal Flood AdvisoryEWXLee116 min
Sep 21, 10:50 PM CDTAreal Flood AdvisoryEWXLee, Travis, Williamson3 hr
Sep 21, 11:24 PM CDTSpecial Weather StatementEWXWilliamson51 min
Sep 22, 12:00 AM CDTAreal Flood AdvisoryEWXBandera, Kendall, Kerr3 hr
Sep 22, 12:28 AM CDTFlash Flood WarningEWXBandera3 hr
Sep 22, 1:01 AM CDTFlash Flood WarningEWXBurnet, Travis, Williamson6 hr
Sep 22, 1:29 AM CDTAreal Flood AdvisoryEWXUvalde3 hr
Sep 22, 1:41 AM CDTAreal Flood AdvisoryEWXMedina3 hr
Sep 22, 1:53 AM CDTSpecial Weather StatementEWXWilliamson37 min
Sep 22, 2:14 AM CDTFlash Flood WarningEWXBandera, Medina3 hr
Sep 22, 2:45 AM CDTRiver Flood WarningEWXWilliamson11 hr
Sep 22, 3:02 AM CDTFlash Flood WarningEWXBexar3 hr
Sep 22, 3:12 AM CDTFlash Flood WarningEWXMedina3 hr
Sep 22, 3:28 AM CDTSpecial Weather StatementEWXMedina32 min
Sep 22, 4:05 AM CDTAreal Flood AdvisoryEWXAtascosa, Frio3 hr
Sep 22, 4:24 AM CDTFlash Flood WarningEWXBexar3 hr
Sep 22, 4:28 AM CDTFlash Flood WarningEWXWilliamson2 hr
Sep 22, 4:33 AM CDTAreal Flood AdvisoryEWXComal, Hays3 hr
Sep 22, 5:11 AM CDTRiver Flood WarningEWXBandera4 hr
Sep 22, 5:22 AM CDTAreal Flood AdvisoryEWXTravis, Williamson113 min
Sep 22, 6:04 AM CDTFlash Flood WarningEWXTravis, Williamson3 hr
Sep 22, 6:21 AM CDTRiver Flood WarningEWXBexar9 hr
Sep 22, 6:37 AM CDTAreal Flood AdvisoryEWXBandera, Bexar, Medina113 min
Sep 22, 8:48 AM CDTRiver Flood WarningEWXBexar36 hr
Sep 22, 8:48 AM CDTRiver Flood WarningEWXMedina26 hr
Sep 22, 8:48 AM CDTRiver Flood WarningEWXBexar55 hr
Sep 22, 9:05 AM CDTRiver Flood WarningEWXFrio3 days
Sep 22, 9:16 AM CDTAreal Flood AdvisoryEWXWilliamson3 hr
Sep 22, 2:30 PM CDTRiver Flood WarningEWXVal Verde22 hr
Sep 22, 2:35 PM CDTRiver Flood WarningEWXBexar, Wilson24 hr
Sep 22, 6:59 PM CDTRiver Flood WarningEWXVal Verde22 hr

Nearby

Flash Flood Warnings in Texas, 2018Every flash flood warning in 2018

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.