Alert archive / Texas / Flash Flood Warnings in 2020

Flash Flood Warning 22, NWS Austin/San Antonio, TX

September 9, 20204 counties in Texas

NWS Austin/San Antonio, TX issued this flash flood warning at Sep 9, 2020, 4:43 AM CDT for 4 counties in 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 9, 2020, 4:43 AM CDT (09:43 UTC)
Expired
Sep 9, 2020, 10:00 AM CDT
In force
5 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Blanco County, TX, Comal County, TX, Gillespie County, TX, Kendall County, TX

The radar

The Austin/San Antonio radar (KEWX), 54 km from the middle of the area, began a volume at 09:45 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 9, 8:02 AM CDTHEAVY RAIN 1.613 Ne Twin Sisters, TXRAINFALL AMOUNT SINCE MIDNIGHT.

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 (KDRT), launched 00:00Z, 9.7 hours before the alert went out and 238 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 00:00Z on 2020-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1077 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 00:00Z on 2020-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
1077 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1412 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

955 
WGUS54 KEWX 090943
FFWEWX
TXC031-091-171-259-091300-
/O.NEW.KEWX.FF.W.0022.200909T0943Z-200909T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
443 AM CDT Wed Sep 9 2020

The National Weather Service in Austin/San Antonio has issued a

* Flash Flood Warning for...
  Blanco County in south central Texas...
  Central Comal County in south central Texas...
  Eastern Gillespie County in south central Texas...
  Northern Kendall County in south central Texas...

* Until 800 AM CDT.

* At 443 AM CDT, Doppler radar indicated numerous thunderstorms 
  producing heavy rain across the warned area. Between 1 and 2 
  inches of rain have fallen. Flash flooding is ongoing or expected 
  to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Doppler radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Fredericksburg, Blanco, Round Mountain, Canyon Lake, Bulverde, 
  Johnson City, Stonewall, Albert, Hye, LBJ State Park, Rocky Creek, 
  Flugrath, Blumenthal, Luckenbach, Sandy, Rocky Hill, Kendalia, 
  Cain City, Grapetown and Bankersmith.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3050 9891 3050 9842 3047 9829 3003 9830
      3004 9830 2973 9834 2973 9835 2973 9837
      2974 9840 2975 9840 2974 9842 2973 9842
      2973 9845 2990 9854 2992 9888

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-3 INCHES IN 2 HOURS 

$$

MO
2 follow-up statements
954 
WGUS74 KEWX 091106
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
606 AM CDT Wed Sep 9 2020

TXC031-091-171-259-091300-
/O.CON.KEWX.FF.W.0022.000000T0000Z-200909T1300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Blanco TX-Comal TX-Gillespie TX-Kendall TX-
606 AM CDT Wed Sep 9 2020

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 AM CDT THIS MORNING 
FOR BLANCO, CENTRAL COMAL, EASTERN GILLESPIE AND NORTHERN KENDALL 
COUNTIES...

At 606 AM CDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 3 inches of rain have 
fallen in a corridor along and just east of the Blanco/Gillespie 
county line, then south to Sisterdale, Kendalia, to Bulverde. Flash 
flooding is ongoing or expected to begin shortly.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Doppler radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include...
  Fredericksburg, Blanco, Round Mountain, Canyon Lake, Bulverde, 
  Johnson City, Stonewall, Albert, Hye, LBJ State Park, Rocky Creek, 
  Flugrath, Blumenthal, Luckenbach, Sandy, Rocky Hill, Kendalia, 
  Cain City, Grapetown and Bankersmith.

Additional rainfall up to 2 inches is possible. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, urban areas, highways, streets and underpasses 
as well as other drainage areas and low lying spots.

&&

LAT...LON 3050 9891 3050 9842 3047 9829 3003 9830
      3004 9830 2973 9834 2973 9835 2973 9837
      2974 9840 2975 9840 2974 9842 2973 9842
      2973 9845 2990 9854 2992 9888

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-3 INCHES IN 2 HOURS 

$$

CP
355 
WGUS54 KEWX 091229
FFWEWX
TXC031-091-171-259-091500-
/O.EXT.KEWX.FF.W.0022.000000T0000Z-200909T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
729 AM CDT Wed Sep 9 2020

The National Weather Service in Austin/San Antonio has extended the

* Flash Flood Warning for...
  Blanco County in south central Texas...
  Central Comal County in south central Texas...
  Eastern Gillespie County in south central Texas...
  Northern Kendall County in south central Texas...

* Until 1000 AM CDT.

* At 729 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 5 inches of rain 
  have fallen. The heaviest rains between 3 and 5 inches were along 
  the Gillespie and Blanco county line east to US 281. Flash 
  flooding is ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Doppler radar.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Fredericksburg, Blanco, Round Mountain, Canyon Lake, Bulverde, 
  Johnson City, Stonewall, Albert, Hye, LBJ State Park, Rocky Creek, 
  Flugrath, Blumenthal, Luckenbach, Sandy, Rocky Hill, Kendalia, 
  Cain City, Grapetown and Bankersmith.

Additional rainfall amounts up to 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.

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 3050 9891 3050 9842 3047 9829 3003 9830
      3004 9830 2973 9834 2973 9835 2973 9837
      2974 9840 2975 9840 2974 9842 2973 9842
      2973 9845 2990 9854 2992 9888

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-3 INCHES IN 2 HOURS 

$$

CP

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 12:01 AM CDTAreal Flood AdvisoryEWXBandera, Edwards, Kendall, Kerr, Kinney, Medina and 3 more6 hr
Sep 9, 2:50 AM CDTAreal Flood AdvisoryEWXBandera, Bexar, Gillespie, Kendall, Medina3 hr
Sep 9, 3:44 AM CDTFlash Flood Warning Considerable damage threatEWXBexar, Comal, Kendall2 hr
Sep 9, 3:53 AM CDTFlash Flood WatchEWXBandera, Bexar, Blanco, Burnet, Comal, Edwards and 12 more33 hr
Sep 9, 4:08 AM CDTFlash Flood Warning Considerable damage threatEWXVal Verde3 hr
Sep 9, 4:29 AM CDTAreal Flood AdvisoryEWXBlanco, Burnet, Comal, Hays, Kendall, Llano and 1 more4 hr
Sep 9, 6:24 AM CDTAreal Flood AdvisoryEWXBexar, Comal, Kendall3 hr
Sep 9, 7:06 AM CDTFlash Flood Warning Considerable damage threatEWXBurnet, Llano3 hr
Sep 9, 7:15 AM CDTAreal Flood AdvisoryEWXBastrop, Caldwell, Gonzales, Guadalupe, Hays, Lee and 3 more3 hr
Sep 9, 7:45 AM CDTFlash Flood Warning Considerable damage threatEWXBastrop, Blanco, Burnet, Caldwell, Comal, Guadalupe and 3 more4 hr
Sep 9, 7:56 AM CDTFlash Flood Warning Considerable damage threatEWXEdwards, Val Verde3 hr
Sep 9, 10:00 AM CDTFlash Flood Warning Considerable damage threatEWXGillespie3 hr
Sep 9, 10:58 AM CDTFlash Flood Warning Considerable damage threatEWXEdwards3 hr
Sep 9, 11:51 AM CDTAreal Flood AdvisoryEWXEdwards, Kerr, Real3 hr
Sep 9, 1:14 PM CDTAreal Flood AdvisoryEWXTravis, Williamson3 hr
Sep 9, 1:38 PM CDTAreal Flood AdvisoryEWXBexar, Caldwell, Comal, Guadalupe, Hays, Travis3 hr
Sep 9, 2:23 PM CDTFlash Flood Warning Considerable damage threatEWXBurnet, Hays, Travis, Williamson3 hr
Sep 9, 5:22 PM CDTAreal Flood AdvisoryEWXTravis3 hr

Nearby

Flash Flood Warnings in Texas, 2020Every flash flood warning in 2020

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.