Alert archive / Texas / Flash Flood Warnings in 2018

Flash Flood Warning 34, NWS Austin/San Antonio, TX

September 9, 20184 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Sep 9, 2018, 10:12 AM CDT for 4 counties in Texas. It was in force for 6 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 9, 2018, 10:12 AM CDT (15:12 UTC)
Expired
Sep 9, 2018, 4:15 PM CDT
In force
6 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Flood severity
None

Counties Caldwell County, TX, Comal County, TX, Guadalupe County, TX, Hays County, TX

The radar

The Austin/San Antonio radar (KEWX), 6 km from the middle of the area, began a volume at 15:13 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

Corpus Christi, TX (KCRP), launched 12:00Z, 3.2 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-pSkew-T log-p diagram, Corpus Christi, TX at 12:00Z on 2018-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1507 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, Corpus Christi, TX at 12:00Z on 2018-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -31 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
1507 J/kg
Mixed-layer CIN
-13 J/kg
Mixed-layer LCL
812 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-31 m²/s²
0-3 km storm-relative helicity
-10 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

065 
WGUS54 KEWX 091512
FFWEWX
TXC055-091-187-209-091815-
/O.NEW.KEWX.FF.W.0034.180909T1512Z-180909T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
1012 AM CDT SUN SEP 9 2018

The National Weather Service in Austin San Antonio has issued a

* Flash Flood Warning for...
  Western Caldwell County in south central Texas...
  Hays County in south central Texas...
  Guadalupe County in south central Texas...
  Comal County in south central Texas...

* Until 115 PM CDT

* At 1012 AM CDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Up to three inches of rain have
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  New Braunfels, San Marcos, Schertz, Kyle, Seguin, Cibolo, Buda,
  Lockhart, Selma, Luling, Dripping Springs, Wimberley, Canyon Lake
  Dam, Canyon Lake, Garden Ridge, McQueeney, Woodcreek, Martindale,
  Marion and Uhland.

Additional rainfall amounts of 1-2 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.

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 3002 9772 2995 9751 2938 9786 2938 9809
      2937 9811 2942 9814 2948 9812 2948 9815
      2955 9823 2955 9826 2959 9831 2999 9835
      3004 9830 3010 9827 3032 9812

$$

HAMPSHIRE
2 follow-up statements
923 
WGUS74 KEWX 091807
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
107 PM CDT SUN SEP 9 2018

TXC055-187-091808-
/O.CAN.KEWX.FF.W.0034.000000T0000Z-180909T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Caldwell TX-Guadalupe TX-
107 PM CDT SUN SEP 9 2018

...THE FLASH FLOOD WARNING FOR WESTERN CALDWELL AND GUADALUPE
COUNTIES IS CANCELLED...

Flooding is no longer expected to pose a threat as Doppler radar 
shows only light rain and moderate to heavy rain is not expected 
across these areas for the rest of the afternoon. However, please 
continue to heed any remaining road closures.

LAT...LON 3002 9772 2994 9780 2988 9789 2986 9790
      2986 9788 2969 9808 2960 9831 2999 9835
      3004 9830 3010 9827 3032 9812

$$

TXC091-209-091815-
/O.CON.KEWX.FF.W.0034.000000T0000Z-180909T1815Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Hays TX-Comal TX-
107 PM CDT SUN SEP 9 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM CDT FOR
HAYS AND COMAL COUNTIES...

At 105 PM CDT, Doppler radar indicated light to moderate showers 
across parts of eastern Comal and most of Hays County. Will keep the 
Flash Flood Warning in effect through 115 PM this afternoon with 
possible extension through this afternoon due to the multiple street 
closures and a lot of ponding of waters across roadways, underpasses 
and low lying 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 3002 9772 2994 9780 2988 9789 2986 9790
      2986 9788 2969 9808 2960 9831 2999 9835
      3004 9830 3010 9827 3032 9812

$$
741 
WGUS54 KEWX 091813
FFWEWX
TXC091-209-092115-
/O.EXT.KEWX.FF.W.0034.000000T0000Z-180909T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
113 PM CDT SUN SEP 9 2018

The National Weather Service in Austin San Antonio has extended the

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

* Until 415 PM CDT

* At 110 PM CDT, Doppler radar indicated light rain across eastern 
  Comal and Hays Counties. However, due to the earlier heavy rain 
  and lots of street closures and ponding of waters across roadways, 
  underpasses, poor and low lying areas, the Flash Flood Warning for 
  Hays and Comal Counties has been extended until 415 PM.

* Additional one tenth to one quarter inch of rainfall possible 
  over the already affected areas for the next several hours.

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 3002 9772 2994 9780 2988 9789 2986 9790
      2986 9788 2969 9808 2960 9831 2999 9835
      3004 9830 3010 9827 3032 9812

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 8, 9:49 PM CDTRiver Flood WarningEWXVal Verde5 hr
Sep 8, 10:27 PM CDTRiver Flood WarningEWXDimmit4 days
Sep 9, 2:12 AM CDTAreal Flood AdvisoryEWXBandera, Medina3 hr
Sep 9, 3:58 AM CDTAreal Flood AdvisoryEWXBexar3 hr
Sep 9, 4:25 AM CDTFlash Flood WarningEWXBandera, Medina6 hr
Sep 9, 4:43 AM CDTFlash Flood WarningEWXBexar, Comal12 hr
Sep 9, 4:57 AM CDTAreal Flood AdvisoryEWXBastrop, Travis3 hr
Sep 9, 5:36 AM CDTAreal Flood AdvisoryEWXComal, Hays114 min
Sep 9, 5:51 AM CDTAreal Flood AdvisoryEWXAtascosa, Karnes, Wilson114 min
Sep 9, 6:35 AM CDTAreal Flood AdvisoryEWXAtascosa, Frio, Medina3 hr
Sep 9, 7:21 AM CDTFlash Flood WarningEWXCaldwell, Comal, Guadalupe, Hays3 hr
Sep 9, 8:09 AM CDTAreal Flood AdvisoryEWXMedina2 hr
Sep 9, 8:11 AM CDTAreal Flood AdvisoryEWXGonzales, Guadalupe, Karnes, Wilson2 hr
Sep 9, 9:00 AM CDTRiver Flood WarningEWXBexar23 hr
Sep 9, 9:00 AM CDTRiver Flood WarningEWXBexar, Wilson54 hr
Sep 9, 9:00 AM CDTRiver Flood WarningEWXKarnes, Wilson3 days
Sep 9, 9:00 AM CDTRiver Flood WarningEWXKarnes, Wilson42 hr
Sep 9, 9:00 AM CDTRiver Flood WarningEWXKarnes72 hr
Sep 9, 9:14 AM CDTRiver Flood WarningEWXGoliad, Karnes7 days
Sep 9, 9:14 AM CDTRiver Flood WarningEWXBexar30 hr
Sep 9, 9:18 AM CDTRiver Flood WarningEWXFrio4 days
Sep 9, 9:49 AM CDTAreal Flood AdvisoryEWXBastrop, Travis3 hr
Sep 9, 10:01 AM CDTFlash Flood WarningEWXBandera, Medina6 hr
Sep 9, 10:56 AM CDTAreal Flood AdvisoryEWXKendall3 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.