Alert archive / Texas / Flash Flood Warnings in 2020

Flash Flood Warning 3, NWS Austin/San Antonio, TX

May 12, 2020Comal County, Texas

NWS Austin/San Antonio, TX issued this flash flood warning at May 12, 2020, 11:28 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: May 12, 2020, 11:28 AM CDT (16:28 UTC)
Expired: May 12, 2020, 2:30 PM CDT
In force: 3 hr
Issued by: NWS Austin/San Antonio, TX
Area: Storm-based polygon
Damage threat: Considerable
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 16:29 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

Time	Report	Where	Remark
May 12, 12:11 PM CDT	FLASH FLOOD	2 S Canyon Lake, TX	PICTURE POSTED ON TWITTER OF FLOODING ONGOING IN PARTS OF STARTZVILLE.

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 12:00Z, 4.5 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 378 J/kg
Mixed-layer CIN: -175 J/kg
Mixed-layer LCL: 861 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 112 m²/s²
0-3 km storm-relative helicity: 149 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

000 
WGUS74 KEWX 201905
FFSSAT
TXC021-031-055-091-209-259-287-453-491-201930-

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE AUSTIN/SAN ANTONIO TX
100 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 130 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 THAT HEAVY RAINS 
CONTINUED TO MOVE ACROSS THE WARNED COUNTIES. ADDITIONAL SHOWERS AND 
THUNDERSTORMS PRODUCING LIGHT TO MODERATE RAINFALL ARE EXPECTED TO
TRAIN ACROSS THE WARNED COUNTIES FOR THE NEXT FEW HOURS.
RAINFALL RATES OF ONE QUARTER TO THREE QUARTERS INCHES AN HOUR ARE 
ESTIMATED BY DOPPLER RADAR. MOVEMENT IS NORTHEAST AT 25 MPH.

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

185 
WGUS54 KEWX 121628
FFWEWX
TXC091-121930-
/O.NEW.KEWX.FF.W.0003.200512T1628Z-200512T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Austin/San Antonio TX
1128 AM CDT Tue May 12 2020

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

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

* Until 230 PM CDT.

* At 1128 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...
  Canyon Lake Dam, Canyon Lake, Bulverde, Smithson Valley, Spring 
  Branch, Fischer, Timberwood Park, Startzville, Sattler and Specht 
  Store.

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, country roads, farmland, and other 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 2974 9852 2990 9838 3000 9825 2987 9807
      2983 9810 2964 9834 2967 9836 2967 9838
      2971 9834 2972 9834 2973 9835 2973 9837
      2975 9840 2975 9841 2974 9842 2973 9842
      2972 9843 2972 9844 2974 9845 2974 9849

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

$$

AAT

878 
WGUS74 KEWX 121902
FFSEWX

Flash Flood Statement
National Weather Service Austin/San Antonio TX
202 PM CDT Tue May 12 2020

TXC091-121930-
/O.CON.KEWX.FF.W.0003.000000T0000Z-200512T1930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Comal TX-
202 PM CDT Tue May 12 2020

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM CDT THIS 
AFTERNOON FOR CENTRAL COMAL COUNTY...

At 202 PM CDT, Flash Flooding is ongoing across parts of the warned 
area. Parts of Startzville saw around 10 inches of rainfall this 
morning while most other parts of the county saw between 4 to 7 
inches. Flooding was reported in Startzville. While rainfall has 
mostly ended across the warned area flooding may still continue 
while waters recede.

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

SOURCE...Public.

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

Some locations that will experience flash flooding include...
  Canyon Lake Dam, Canyon Lake, Bulverde, Smithson Valley, Spring 
  Branch, Fischer, Timberwood Park, Startzville, Sattler and Specht 
  Store.

Additional rainfall amounts up to 1 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.

Excessive runoff from heavy rainfall will cause flooding of small 
creeks and streams, country roads, farmland, and other 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 2974 9852 2990 9838 3000 9825 2987 9807
      2983 9810 2964 9834 2967 9836 2967 9838
      2971 9834 2972 9834 2973 9835 2973 9837
      2975 9840 2975 9841 2974 9842 2973 9842
      2972 9843 2972 9844 2974 9845 2974 9849

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

AAT

The office that day

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

Issued	Product	Office	Counties	Lasted
May 11, 10:00 PM CDT	Special Weather Statement	EWX	Val Verde	30 min
May 11, 10:41 PM CDT	Special Weather Statement	EWX	Val Verde	49 min
May 11, 11:31 PM CDT	Special Weather Statement	EWX	Val Verde	44 min
May 12, 12:36 AM CDT	Special Weather Statement	EWX	Maverick	39 min
May 12, 1:12 AM CDT	Special Weather Statement	EWX	Val Verde	48 min
May 12, 1:13 AM CDT	Special Weather Statement	EWX	Maverick	32 min
May 12, 1:30 AM CDT	Special Weather Statement	EWX	Dimmit	45 min
May 12, 2:33 AM CDT	Special Weather Statement	EWX	Val Verde	27 min
May 12, 2:50 AM CDT	Areal Flood Advisory	EWX	Val Verde	3 hr
May 12, 2:51 AM CDT	Special Weather Statement	EWX	Frio	39 min
May 12, 3:01 AM CDT	Special Weather Statement	EWX	Edwards	44 min
May 12, 3:29 AM CDT	Special Weather Statement	EWX	Val Verde	46 min
May 12, 3:47 AM CDT	Special Weather Statement	EWX	Edwards	43 min
May 12, 8:39 AM CDT	Special Weather Statement	EWX	Caldwell	51 min
May 12, 9:06 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell, Hays, Travis	54 min
May 12, 9:08 AM CDT	Tornado Warning	EWX	Bastrop, Caldwell	37 min
May 12, 9:37 AM CDT	Tornado Warning	EWX	Bastrop, Fayette	23 min
May 12, 9:41 AM CDT	Tornado Warning Tornado observed	EWX	Bastrop	19 min
May 12, 10:01 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Caldwell	59 min
May 12, 10:12 AM CDT	Severe Thunderstorm Warning	EWX	Bastrop, Lee	48 min
May 12, 10:18 AM CDT	Tornado Warning	EWX	Bastrop, Fayette, Lee	27 min
May 12, 10:19 AM CDT	Tornado Warning	EWX	Bastrop	26 min
May 12, 10:28 AM CDT	Areal Flood Advisory	EWX	Bexar, Comal	3 hr
May 12, 10:36 AM CDT	Tornado Warning	EWX	Bastrop, Fayette	24 min
May 12, 10:40 AM CDT	Tornado Warning	EWX	Bastrop, Lee	35 min
May 12, 10:50 AM CDT	Tornado Warning	EWX	Bexar, Comal, Kendall	25 min
May 12, 10:53 AM CDT	Tornado Warning	EWX	Bastrop, Lee	37 min
May 12, 11:08 AM CDT	Areal Flood Advisory	EWX	Comal, Hays, Travis	3 hr
May 12, 11:10 AM CDT	Tornado Warning	EWX	Lee	35 min
May 12, 11:14 AM CDT	Severe Thunderstorm Warning	EWX	Bexar, Comal, Kendall	61 min
May 12, 11:25 AM CDT	Tornado Warning	EWX	Bastrop, Lee	35 min
May 12, 11:41 AM CDT	Severe Thunderstorm Warning	EWX	Lee	34 min
May 12, 11:52 AM CDT	Flash Flood Warning Considerable damage threat	EWX	Hays, Travis	3 hr
May 12, 11:55 AM CDT	Tornado Warning	EWX	Lee	35 min
May 12, 12:10 PM CDT	Special Weather Statement	EWX	Comal	50 min
May 12, 12:23 PM CDT	Tornado Warning	EWX	Comal, Hays	19 min
May 12, 12:27 PM CDT	Severe Thunderstorm Warning	EWX	Lee	18 min
May 12, 12:45 PM CDT	Areal Flood Advisory	EWX	Bastrop, Caldwell, Guadalupe, Hays, Lee, Travis	3 hr
May 12, 12:48 PM CDT	Special Weather Statement	EWX	Caldwell	42 min
May 12, 12:54 PM CDT	Special Weather Statement	EWX	Bastrop	51 min
May 12, 12:55 PM CDT	River Flood Warning	EWX	Travis	7 hr
May 12, 1:23 PM CDT	Special Weather Statement	EWX	Caldwell	52 min
May 12, 1:36 PM CDT	Special Weather Statement	EWX	Caldwell	39 min
May 12, 2:10 PM CDT	Special Weather Statement	EWX	Gonzales	50 min
May 12, 2:22 PM CDT	Areal Flood Advisory	EWX	Comal, Hays, Travis	83 min
May 12, 2:36 PM CDT	Special Weather Statement	EWX	Gonzales	39 min
May 12, 2:44 PM CDT	River Flood Warning	EWX	Comal, Guadalupe	5 hr
May 12, 2:57 PM CDT	Special Weather Statement	EWX	Guadalupe	33 min
May 12, 3:14 PM CDT	Severe Thunderstorm Warning	EWX	Gonzales	20 min
May 12, 3:51 PM CDT	Areal Flood Advisory	EWX	Fayette, Gonzales, Lavaca	5 hr
May 12, 5:07 PM CDT	Special Weather Statement	EWX	Lavaca	38 min
May 12, 5:27 PM CDT	Special Weather Statement	EWX	Guadalupe	63 min
May 12, 5:42 PM CDT	Special Weather Statement	EWX	Comal	48 min
May 12, 5:50 PM CDT	Areal Flood Advisory	EWX	DeWitt, Gonzales, Lavaca	3 hr
May 12, 5:54 PM CDT	Special Weather Statement	EWX	Lavaca	66 min
May 12, 5:58 PM CDT	Severe Thunderstorm Warning	EWX	Comal, Kendall	47 min
May 12, 6:19 PM CDT	Special Weather Statement	EWX	DeWitt, Wilson	56 min
May 12, 6:26 PM CDT	Special Weather Statement	EWX	Gonzales	64 min
May 12, 6:35 PM CDT	Severe Thunderstorm Warning	EWX	DeWitt	40 min
May 12, 6:42 PM CDT	Special Weather Statement	EWX	Guadalupe	48 min

Nearby

Flash Flood Warnings in Texas, 2020 Every 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.