Alert archive / Texas / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS Austin/San Antonio, TX

April 17, 2017Comal County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Apr 17, 2017, 2:11 PM CDT for Comal County, Texas. It was in force for 3 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
Apr 17, 2017, 2:11 PM CDT (19:11 UTC)
Expired
Apr 17, 2017, 5:15 PM CDT
In force
3 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

County Comal County, TX

The radar

The Austin/San Antonio radar (KEWX), 33 km from the middle of the area, began a volume at 19:10 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
Apr 17, 3:30 PM CDTFLASH FLOOD9 Sw Canyon Lake Dam, TXPORTIONS OF SMITHSON VALLEY ROAD CLOSED DUE TO WATER OVER THE ROADWAY.

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

The nearest sounding before it

Del Rio, TX (KDLF), launched 12:00Z, 7.2 hours before the alert went out and 243 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, Del Rio, TX at 12:00Z on 2017-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 39 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Del Rio, TX at 12:00Z on 2017-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
39 J/kg
Mixed-layer CIN
-540 J/kg
Mixed-layer LCL
1057 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
-33 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

The text

As transmitted.

343 
WGUS54 KEWX 171911
FFWEWX
TXC091-172215-
/O.NEW.KEWX.FF.W.0013.170417T1911Z-170417T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
211 PM CDT MON APR 17 2017

The National Weather Service in Austin San Antonio has issued a

* Flash Flood Warning for...
  Central Comal County in south central Texas...

* Until 515 PM CDT

* At 209 PM CDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the central and southern 
  part of Bexar County. Up to three inches of rain have already 
  fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Canyon Lake, Bulverde, Spring Branch, Smithson Valley and
  Startzville.

Additional rainfall amounts of two inches are possible in the 
already affected areas.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2985 9822 2966 9832 2969 9838 2971 9838
      2970 9835 2971 9834 2973 9835 2972 9838
      2973 9838 2975 9841 2972 9843 2974 9845
      2974 9850 2993 9840

$$
4 follow-up statements
693 
WGUS74 KEWX 171938
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
238 PM CDT MON APR 17 2017

TXC091-172215-
/O.CON.KEWX.FF.W.0013.000000T0000Z-170417T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Comal TX-
238 PM CDT MON APR 17 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR
CENTRAL COMAL COUNTY...

At 235 PM CDT, Doppler radar continues to show heavy rain affecting 
the central and southern parts of Bexar County. As of 235 PM, there 
was a street closure at the intersection of Smithson Valley Road and 
Lonesome Dove. Also, the Cibolo Creek gauge at Smithson Valley Road 
near Bulverde has came up a foot since the heavy rain began.

Some locations that will experience flooding include...
Canyon Lake, Bulverde, Spring Branch, Smithson Valley and
Startzville.

Additional rainfall amounts of one to two inches are possible in the 
already affected areas as showers continues.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2985 9822 2966 9832 2969 9838 2971 9838
      2970 9835 2971 9834 2973 9835 2972 9838
      2973 9838 2975 9841 2972 9843 2974 9845
      2974 9850 2993 9840

$$
313 
WGUS74 KEWX 172038
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
338 PM CDT MON APR 17 2017

TXC091-172215-
/O.CON.KEWX.FF.W.0013.000000T0000Z-170417T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Comal TX-
338 PM CDT MON APR 17 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR
CENTRAL COMAL COUNTY...

At 330 PM CDT, Doppler radar indicated another round of 
thunderstorms producing heavy rain moving into Central Comal County. 
Up to five inches of rain have already fallen along State highway 46 
corridor, Smithson Valley road area, to just northeast of Cibolo 
Creek. Flash flooding is expected to continue with new flash 
flooding beginning shortly.

Some locations that will experience flooding include...
Canyon Lake, Bulverde, Spring Branch, Smithson Valley and
Startzville.

Additional rainfall amounts of 1 to 3 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.

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

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 2985 9822 2966 9832 2969 9838 2971 9838
      2970 9835 2971 9834 2973 9835 2972 9838
      2973 9838 2975 9841 2972 9843 2974 9845
      2974 9850 2993 9840

$$

CP
791 
WGUS74 KEWX 172124
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
424 PM CDT MON APR 17 2017

TXC091-172215-
/O.CON.KEWX.FF.W.0013.000000T0000Z-170417T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Comal TX-
424 PM CDT MON APR 17 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM CDT FOR
CENTRAL COMAL COUNTY...

At 422 PM CDT, Doppler radar indicated light rain across Comal 
County. Up to five inches of rain have already fallen along state 
highway 46 corridor, Smithson Valley road area, to just northeast of 
Cibolo Creek. Flash flooding will continue from the earlier heavy 
rain. 

Some locations that will experience flooding include...
Canyon Lake, Bulverde, Spring Branch, Smithson Valley and
Startzville.

Additional rainfall amounts of up to one quarter inch are possible 
in the warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

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 2985 9822 2966 9832 2969 9838 2971 9838
      2970 9835 2971 9834 2973 9835 2972 9838
      2973 9838 2975 9841 2972 9843 2974 9845
      2974 9850 2993 9840

$$

CP
795 
WGUS74 KEWX 172214
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
514 PM CDT MON APR 17 2017

TXC091-172221-
/O.EXP.KEWX.FF.W.0013.000000T0000Z-170417T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Comal TX-
514 PM CDT MON APR 17 2017

...THE FLASH FLOOD WARNING FOR CENTRAL COMAL COUNTY WILL EXPIRE AT
515 PM CDT...

The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed any 
remaining road closures. Some ponding of water will remain for an 
hour or two. 

LAT...LON 2985 9822 2966 9832 2969 9838 2971 9838
      2970 9835 2971 9834 2973 9835 2972 9838
      2973 9838 2975 9841 2972 9843 2974 9845
      2974 9850 2993 9840

$$

CP

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 16, 7:43 PM CDTSpecial Weather StatementEWXZavala32 min
Apr 16, 7:58 PM CDTSpecial Weather StatementEWXMaverick47 min
Apr 16, 8:04 PM CDTSevere Thunderstorm WarningEWXVal Verde41 min
Apr 16, 8:07 PM CDTSevere Thunderstorm WarningEWXMaverick, Zavala53 min
Apr 16, 8:19 PM CDTAreal Flood AdvisoryEWXDimmit, Maverick, Zavala3 hr
Apr 16, 8:26 PM CDTSevere Thunderstorm WarningEWXKinney64 min
Apr 16, 8:35 PM CDTSevere Thunderstorm WarningEWXKinney, Maverick, Uvalde55 min
Apr 16, 8:37 PM CDTSpecial Weather StatementEWXDimmit23 min
Apr 16, 8:47 PM CDTFlash Flood WatchEWXBandera, Dimmit, Edwards, Frio, Kerr, Kinney and 6 more6 hr
Apr 16, 9:03 PM CDTSevere Thunderstorm WarningEWXDimmit, Kinney, Maverick, Zavala42 min
Apr 16, 9:13 PM CDTFlash Flood WarningEWXDimmit, Kinney, Maverick, Uvalde, Zavala3 hr
Apr 16, 9:28 PM CDTSpecial Weather StatementEWXEdwards, Real, Uvalde62 min
Apr 16, 9:30 PM CDTSpecial Weather StatementEWXKinney60 min
Apr 16, 9:42 PM CDTSevere Thunderstorm WarningEWXDimmit, Maverick30 min
Apr 16, 9:52 PM CDTAreal Flood AdvisoryEWXEdwards, Real3 hr
Apr 16, 10:11 PM CDTSpecial Weather StatementEWXEdwards, Kinney, Maverick, Real, Uvalde, Zavala64 min
Apr 16, 10:32 PM CDTSevere Thunderstorm WarningEWXMaverick44 min
Apr 16, 10:48 PM CDTSpecial Weather StatementEWXBandera, Dimmit, Edwards, Frio, Kerr, Kinney and 5 more57 min
Apr 16, 11:21 PM CDTAreal Flood AdvisoryEWXBandera, Frio, Kerr, Medina, Real, Uvalde and 1 more3 hr
Apr 16, 11:46 PM CDTSpecial Weather StatementEWXBandera, Frio, Gillespie, Kerr, Medina59 min
Apr 16, 11:47 PM CDTSpecial Weather StatementEWXDimmit, Maverick, Zavala58 min
Apr 17, 12:15 AM CDTAreal Flood AdvisoryEWXDimmit, Maverick, Zavala3 hr
Apr 17, 1:12 AM CDTSpecial Weather StatementEWXZavala48 min
Apr 17, 1:05 PM CDTSpecial Weather StatementEWXFayette, Lavaca40 min
Apr 17, 1:50 PM CDTAreal Flood AdvisoryEWXLavaca3 hr
Apr 17, 1:51 PM CDTAreal Flood AdvisoryEWXComal3 hr
Apr 17, 3:53 PM CDTAreal Flood AdvisoryEWXGuadalupe3 hr
Apr 17, 4:52 PM CDTSpecial Weather StatementEWXUvalde38 min
Apr 17, 4:57 PM CDTSpecial Weather StatementEWXGonzales33 min
Apr 17, 5:05 PM CDTSpecial Weather StatementEWXUvalde40 min
Apr 17, 5:28 PM CDTSpecial Weather StatementEWXDeWitt32 min
Apr 17, 5:43 PM CDTSevere Thunderstorm WarningEWXFrio, Zavala62 min

Nearby

Flash Flood Warnings in Texas, 2017Every 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.