Alert archive / Texas / Flash Flood Warnings in 2020

Flash Flood Warning 4, NWS Austin/San Antonio, TX

May 12, 2020Hays County, Travis County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at May 12, 2020, 11:52 AM CDT for Hays County, Travis 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
May 12, 2020, 11:52 AM CDT (16:52 UTC)
Expired
May 12, 2020, 3:00 PM CDT
In force
3 hr
Issued by
NWS Austin/San Antonio, TX
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Hays County, TX, Travis County, TX

The radar

The Austin/San Antonio radar (KEWX), 53 km from the middle of the area, began a volume at 16:52 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
May 12, 12:48 PM CDTFLASH FLOOD1 Nnw Onion Creek, TXREPORTS OF WATER OVER THE ROAD WAY VIA AUSTIN FEWS CAMERA AT OLD SAN ANTONIO ROAD IN SOUTH AUSTIN. OTHER MPING REPORTS AROUND AUSTIN OF PONDING ON ROADWAYS.

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 12:00Z, 4.9 hours before the alert went out and 273 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 2020-05-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1021 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 2020-05-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 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
1021 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
847 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
155 m²/s²
Significant tornado parameter
0.5
Supercell composite
5.5

Open this sounding in Storm Lab

The text

As transmitted.

000 
WGUS74 KEWX 201940
FFSSAT
TXC021-031-055-091-209-259-287-453-491-202200-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
130 PM PM CST THU FEB 20 2003

...A FLASH FLOOD WARNING CONTINUES FOR WILLIAMSON...TRAVIS...LEE...  
   BLANCO...BASTROP...HAYS...KENDALL...CALDWELL AND COMAL COUNTIES   
   UNTIL 530 PM CST...

...FLASH FLOOD WATCH IN EFFECT TODAY AND TONIGHT FOR ALL OF SOUTH    
   CENTRAL TEXAS AND THE TEXAS HILL COUNTRY...

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SHOWERS AND 
THUNDERSTORMS PRODUCING MODERATE TO HEAVY RAINFALL MOVING ACROSS THE 
WARNED COUNTIES. RAINFALL RATES OF ONE QUARTER TO THREE QUARTERS 
INCHES AN HOUR ARE ESTIMATED BY DOPPLER RADAR. MOVEMENT IS NORTHEAST 
AT 25 MPH. ADDITIONAL SHOWERS AND THUNDERSTORM DEVELOPMENT IS 
EXPECTED THROUGH THE REMAINDER OF THE DAY AND TONIGHT. 

EXCESSIVE RUNOFF WILL CONTINUE FOR THE NEXT FEW HOURS FROM THESE 
STORMS. THIS WILL RESULT IN CONTINUED FLASH FLOODING OF SMALL CREEKS 
AND STREAMS...LOW WATER CROSSINGS AND UNDERPASSES AS WELL AS OTHER 
DRAINAGE AREAS AND LOW LYING AREAS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROAD.
VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. 
STAY TUNED TO LOCAL MEDIA OUTLETS FOR THE LATEST WEATHER INFORMATION.

$$
2 follow-up statements
000 
WGUS74 KEWX 202131
FFSSAT
TXC021-031-055-091-209-259-287-453-491-202330-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
330 PM PM CST THU FEB 20 2003

...A FLASH FLOOD WARNING CONTINUES FOR WILLIAMSON...TRAVIS...LEE...  
   BLANCO...BASTROP...HAYS...KENDALL...CALDWELL AND COMAL COUNTIES   
   UNTIL 530 PM CST...

...FLASH FLOOD WATCH IN EFFECT TODAY AND TONIGHT FOR ALL OF SOUTH    
   CENTRAL TEXAS AND THE TEXAS HILL COUNTRY...

NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED SCATTERED SHOWERS 
AND THUNDERSTORMS PRODUCING MODERATE TO HEAVY RAINFALL MOVING ACROSS 
THE WARNED COUNTIES. RAINFALL RATES OF ONE QUARTER TO THREE QUARTER 
INCHES AN HOUR ARE ESTIMATED BY DOPPLER RADAR. MOVEMENT IS NORTHEAST 
AT 25 MPH. ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT IS 
EXPECTED THROUGH THE REMAINDER OF THIS AFTERNOON AND INTO THE NIGHT. 

EXCESSIVE RUNOFF WILL CONTINUE FOR THE NEXT FEW HOURS FROM THESE 
STORMS. THIS WILL RESULT IN CONTINUED FLASH FLOODING OF SMALL CREEKS 
AND STREAMS...LOW WATER CROSSINGS AND UNDERPASSES AS WELL AS OTHER 
DRAINAGE AREAS AND LOW LYING AREAS.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROAD.
VEHICLES CAUGHT IN RISING WATER SHOULD BE ABANDONED QUICKLY. 
STAY TUNED TO LOCAL MEDIA OUTLETS FOR THE LATEST WEATHER INFORMATION.

$$
712 
WGUS54 KEWX 121652
FFWEWX
TXC209-453-122000-
/O.NEW.KEWX.FF.W.0004.200512T1652Z-200512T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
1152 AM CDT Tue May 12 2020

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

* Flash Flood Warning for...
  East Central Hays County in south central Texas...
  South Central Travis County in south central Texas...

* Until 300 PM CDT.

* At 1152 AM CDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 2 and 3 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...
  Austin, Kyle, Buda, Tanglewood Forest, Rollingwood, Onion Creek, 
  Shady Hollow, Manchaca, Mountain City, Sunset Valley, San Leanna, 
  Hays, Creedmoor and McKinney Falls State Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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.

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 3015 9793 3022 9789 3025 9781 3029 9775
      3027 9769 3021 9771 3010 9774 3003 9780
      3000 9783 3001 9794 3014 9793

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2.5 INCHES IN 3 HOURS 

$$

AAT

The office that day

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

IssuedProductOfficeCountiesLasted
May 11, 10:00 PM CDTSpecial Weather StatementEWXVal Verde30 min
May 11, 10:41 PM CDTSpecial Weather StatementEWXVal Verde49 min
May 11, 11:31 PM CDTSpecial Weather StatementEWXVal Verde44 min
May 12, 12:36 AM CDTSpecial Weather StatementEWXMaverick39 min
May 12, 1:12 AM CDTSpecial Weather StatementEWXVal Verde48 min
May 12, 1:13 AM CDTSpecial Weather StatementEWXMaverick32 min
May 12, 1:30 AM CDTSpecial Weather StatementEWXDimmit45 min
May 12, 2:33 AM CDTSpecial Weather StatementEWXVal Verde27 min
May 12, 2:50 AM CDTAreal Flood AdvisoryEWXVal Verde3 hr
May 12, 2:51 AM CDTSpecial Weather StatementEWXFrio39 min
May 12, 3:01 AM CDTSpecial Weather StatementEWXEdwards44 min
May 12, 3:29 AM CDTSpecial Weather StatementEWXVal Verde46 min
May 12, 3:47 AM CDTSpecial Weather StatementEWXEdwards43 min
May 12, 8:39 AM CDTSpecial Weather StatementEWXCaldwell51 min
May 12, 9:06 AM CDTSevere Thunderstorm WarningEWXBastrop, Caldwell, Hays, Travis54 min
May 12, 9:08 AM CDTTornado WarningEWXBastrop, Caldwell37 min
May 12, 9:37 AM CDTTornado WarningEWXBastrop, Fayette23 min
May 12, 9:41 AM CDTTornado Warning Tornado observedEWXBastrop19 min
May 12, 10:01 AM CDTSevere Thunderstorm WarningEWXBastrop, Caldwell59 min
May 12, 10:12 AM CDTSevere Thunderstorm WarningEWXBastrop, Lee48 min
May 12, 10:18 AM CDTTornado WarningEWXBastrop, Fayette, Lee27 min
May 12, 10:19 AM CDTTornado WarningEWXBastrop26 min
May 12, 10:28 AM CDTAreal Flood AdvisoryEWXBexar, Comal3 hr
May 12, 10:36 AM CDTTornado WarningEWXBastrop, Fayette24 min
May 12, 10:40 AM CDTTornado WarningEWXBastrop, Lee35 min
May 12, 10:50 AM CDTTornado WarningEWXBexar, Comal, Kendall25 min
May 12, 10:53 AM CDTTornado WarningEWXBastrop, Lee37 min
May 12, 11:08 AM CDTAreal Flood AdvisoryEWXComal, Hays, Travis3 hr
May 12, 11:10 AM CDTTornado WarningEWXLee35 min
May 12, 11:14 AM CDTSevere Thunderstorm WarningEWXBexar, Comal, Kendall61 min
May 12, 11:25 AM CDTTornado WarningEWXBastrop, Lee35 min
May 12, 11:28 AM CDTFlash Flood Warning Considerable damage threatEWXComal3 hr
May 12, 11:41 AM CDTSevere Thunderstorm WarningEWXLee34 min
May 12, 11:55 AM CDTTornado WarningEWXLee35 min
May 12, 12:10 PM CDTSpecial Weather StatementEWXComal50 min
May 12, 12:23 PM CDTTornado WarningEWXComal, Hays19 min
May 12, 12:27 PM CDTSevere Thunderstorm WarningEWXLee18 min
May 12, 12:45 PM CDTAreal Flood AdvisoryEWXBastrop, Caldwell, Guadalupe, Hays, Lee, Travis3 hr
May 12, 12:48 PM CDTSpecial Weather StatementEWXCaldwell42 min
May 12, 12:54 PM CDTSpecial Weather StatementEWXBastrop51 min
May 12, 12:55 PM CDTRiver Flood WarningEWXTravis7 hr
May 12, 1:23 PM CDTSpecial Weather StatementEWXCaldwell52 min
May 12, 1:36 PM CDTSpecial Weather StatementEWXCaldwell39 min
May 12, 2:10 PM CDTSpecial Weather StatementEWXGonzales50 min
May 12, 2:22 PM CDTAreal Flood AdvisoryEWXComal, Hays, Travis83 min
May 12, 2:36 PM CDTSpecial Weather StatementEWXGonzales39 min
May 12, 2:44 PM CDTRiver Flood WarningEWXComal, Guadalupe5 hr
May 12, 2:57 PM CDTSpecial Weather StatementEWXGuadalupe33 min
May 12, 3:14 PM CDTSevere Thunderstorm WarningEWXGonzales20 min
May 12, 3:51 PM CDTAreal Flood AdvisoryEWXFayette, Gonzales, Lavaca5 hr
May 12, 5:07 PM CDTSpecial Weather StatementEWXLavaca38 min
May 12, 5:27 PM CDTSpecial Weather StatementEWXGuadalupe63 min
May 12, 5:42 PM CDTSpecial Weather StatementEWXComal48 min
May 12, 5:50 PM CDTAreal Flood AdvisoryEWXDeWitt, Gonzales, Lavaca3 hr
May 12, 5:54 PM CDTSpecial Weather StatementEWXLavaca66 min
May 12, 5:58 PM CDTSevere Thunderstorm WarningEWXComal, Kendall47 min
May 12, 6:19 PM CDTSpecial Weather StatementEWXDeWitt, Wilson56 min
May 12, 6:26 PM CDTSpecial Weather StatementEWXGonzales64 min
May 12, 6:35 PM CDTSevere Thunderstorm WarningEWXDeWitt40 min
May 12, 6:42 PM CDTSpecial Weather StatementEWXGuadalupe48 min

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.