Alert archive / Texas / Flash Flood Warnings in 2016

Flash Flood Warning 82, NWS Austin/San Antonio, TX

August 21, 2016Comal County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Aug 21, 2016, 3:06 AM 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
Aug 21, 2016, 3:06 AM CDT (08:06 UTC)
Expired
Aug 21, 2016, 6:00 AM 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), 26 km from the middle of the area, began a volume at 08:09 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.

What was reported inside it

TimeReportWhereRemark
Aug 21, 4:45 AM CDTFLASH FLOOD3 Wnw Gruene, TXSEVERAL LOW WATER CROSSINGS BEGINNING TO FLOOD IN COMAL COUNTY. LOW WATER CROSSINGS ON HUECO SPRINGS LOOP RD... RIVER CANYON... STAHL LANE... AND SMITHSON VALLEY RD 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, 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-pSkew-T log-p diagram, Corpus Christi, TX at 00:00Z on 2016-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1565 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 00:00Z on 2016-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
1565 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1049 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.8

Open this sounding in Storm Lab

The text

As transmitted.

267 
WGUS54 KEWX 210806
FFWEWX
TXC091-211100-
/O.NEW.KEWX.FF.W.0082.160821T0806Z-160821T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
306 AM CDT SUN AUG 21 2016

THE NATIONAL WEATHER SERVICE IN AUSTIN SAN ANTONIO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  COMAL COUNTY IN SOUTH CENTRAL TEXAS...

* UNTIL 600 AM CDT

* AT 301 AM CDT...DOPPLER RADAR INDICATED HEAVY RAIN ACROSS MOST OF
  COMAL COUNTY WITH THE EXCEPTION OF THE FAR NORTH. UP TO 1.5 INCHES
  OF RAIN HAS ALREADY FALLEN BETWEEN SMITHSON VALLEY AND NEW
  BRAUNFELS. THIS ACTIVITY IS EXPECTED TO CONTINUE AS SHOWERS SLOWLY
  PUSH TO THE SOUTH. FLASH FLOODING IS EXPECTED TO BEGIN SHORTLY.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  NEW BRAUNFELS...CANYON LAKE DAM...SCHERTZ...SELMA...CANYON LAKE...
  BULVERDE...GARDEN RIDGE...NORTHCLIFF...BRACKEN...HUNTER...SOLMS...
  GRUENE...SPECHT STORE...SATTLER...FREIHEIT AND STARTZVILLE.

ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO 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.

&&

LAT...LON 2985 9803 2977 9800 2968 9810 2959 9831
      2962 9834 2965 9834 2967 9838 2970 9838
      2972 9834 2973 9835 2972 9838 2973 9838
      2975 9841 2971 9843 2974 9845 2975 9853
      2997 9820

$$
1 follow-up statement
448 
WGUS74 KEWX 211042
FFSEWX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
542 AM CDT SUN AUG 21 2016

TXC091-211100-
/O.CON.KEWX.FF.W.0082.000000T0000Z-160821T1100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
COMAL TX-
542 AM CDT SUN AUG 21 2016

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 600 AM CDT FOR
SOUTHERN COMAL COUNTY...

AT 536 AM CDT...DOPPLER RADAR INDICATED LIGHT TO MODERATE RAIN
MAINLY ACROSS THE WESTERN PART OF COMAL COUNTY. THERE ARE SEVERAL
LOW WATER CROSSINGS CLOSED DUE TO FLOODING ACROSS THE AREA. FLASH
FLOODING IS ALREADY OCCURRING AND THE FLASH FLOOD WARNING WILL BE
EXTENDED IN TIME SHORTLY FOR THE CENTRAL AND WESTERN PART OF COMAL
COUNTY.

SOME LOCATIONS THAT WILL CONTINUE TO EXPERIENCE FLOODING INCLUDE...
NEW BRAUNFELS...SCHERTZ...SELMA...CANYON LAKE...BULVERDE...
GARDEN RIDGE...NORTHCLIFF...BRACKEN...SOLMS...GRUENE...
SPECHT STORE...FREIHEIT AND STARTZVILLE.


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 2977 9800 2968 9810 2959 9831 2962 9834
      2965 9834 2967 9838 2970 9838 2972 9834
      2973 9835 2972 9838 2973 9838 2975 9841
      2971 9843 2974 9845 2975 9853 2987 9835

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 7:03 PM CDTFlash Flood WarningEWXAtascosa, Gonzales, Guadalupe, Wilson9 hr
Aug 20, 9:15 PM CDTAreal Flood AdvisoryEWXFayette, Gonzales, Lavaca3 hr
Aug 20, 9:46 PM CDTRiver Flood WarningEWXGonzales3 days
Aug 20, 10:59 PM CDTAreal Flood AdvisoryEWXBexar3 hr
Aug 20, 11:23 PM CDTRiver Flood WarningEWXTravis14 hr
Aug 20, 11:32 PM CDTAreal Flood AdvisoryEWXDeWitt, Gonzales, Karnes3 hr
Aug 21, 12:39 AM CDTRiver Flood WarningEWXKarnes38 hr
Aug 21, 12:45 AM CDTAreal Flood AdvisoryEWXLee, Williamson3 hr
Aug 21, 12:50 AM CDTAreal Flood AdvisoryEWXDeWitt3 hr
Aug 21, 1:04 AM CDTAreal Flood AdvisoryEWXAtascosa, Frio3 hr
Aug 21, 1:39 AM CDTAreal Flood AdvisoryEWXBexar3 hr
Aug 21, 1:48 AM CDTFlash Flood WarningEWXAtascosa, Bexar, Frio5 hr
Aug 21, 1:54 AM CDTAreal Flood AdvisoryEWXBastrop, Travis3 hr
Aug 21, 2:27 AM CDTAreal Flood AdvisoryEWXComal3 hr
Aug 21, 3:17 AM CDTAreal Flood AdvisoryEWXTravis, Williamson3 hr
Aug 21, 3:29 AM CDTRiver Flood WarningEWXDeWitt58 hr
Aug 21, 4:03 AM CDTRiver Flood WarningEWXKarnes24 hr
Aug 21, 4:07 AM CDTAreal Flood AdvisoryEWXMedina113 min
Aug 21, 5:04 AM CDTAreal Flood AdvisoryEWXBexar116 min
Aug 21, 5:17 AM CDTFlash Flood WarningEWXMedina3 hr
Aug 21, 5:21 AM CDTRiver Flood WarningEWXGonzales20 hr
Aug 21, 5:41 AM CDTRiver Flood WarningEWXBexar, Wilson49 hr
Aug 21, 5:41 AM CDTRiver Flood WarningEWXBexar23 hr
Aug 21, 5:52 AM CDTFlash Flood WarningEWXComal113 min
Aug 21, 6:01 AM CDTAreal Flood AdvisoryEWXKendall3 hr
Aug 21, 6:19 AM CDTAreal Flood AdvisoryEWXTravis, Williamson116 min
Aug 21, 6:38 AM CDTFlash Flood WarningEWXAtascosa, Bexar, Frio3 hr
Aug 21, 8:41 AM CDTAreal Flood AdvisoryEWXUvalde, Zavala2 hr
Aug 21, 9:23 AM CDTFlash Flood WarningEWXZavala3 hr
Aug 21, 10:55 AM CDTAreal Flood AdvisoryEWXDeWitt, Gonzales, Guadalupe, Karnes, Wilson110 min
Aug 21, 11:25 AM CDTFlash Flood WarningEWXDeWitt, Gonzales, Guadalupe, Karnes, Wilson5 hr
Aug 21, 2:42 PM CDTAreal Flood AdvisoryEWXFayette2 hr

Nearby

Flash Flood Warnings in Texas, 2016Every flash flood warning in 2016

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.