Alert archive / Texas / Flash Flood Watches in 2021
Flash Flood Watch 1, NWS Austin/San Antonio, TX
NWS Austin/San Antonio, TX issued this flash flood watch at Apr 30, 2021, 3:34 AM CDT for 21 counties in Texas. It took effect at Apr 30, 2021, 7:00 AM CDT. It was in force for 36 hr.
The area
The counties it named.
The facts
- Issued
- Apr 30, 2021, 3:34 AM CDT (08:34 UTC)
- In effect from
- Apr 30, 2021, 7:00 AM CDT
- Expired
- May 1, 2021, 7:00 PM CDT
- In force
- 36 hr
- Issued by
- NWS Austin/San Antonio, TX
- Flood severity
- None
All 21 counties
Atascosa County, TX, Bandera County, TX, Bastrop County, TX, Bexar County, TX, Blanco County, TX, Caldwell County, TX, Comal County, TX, DeWitt County, TX, Fayette County, TX, Gillespie County, TX, Gonzales County, TX, Guadalupe County, TX, Hays County, TX, Karnes County, TX, Kendall County, TX, Kerr County, TX, Lavaca County, TX, Lee County, TX, Medina County, TX, Travis County, TX, Wilson County, TX
The radar
The Austin/San Antonio radar (KEWX), 4 km from the middle of the area, began a volume at 08:33 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 00:00Z, 8.6 hours before the alert went out and 231 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.
- Mixed-layer CAPE
- 1919 J/kg
- Mixed-layer CIN
- -34 J/kg
- Mixed-layer LCL
- 738 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- -55 m²/s²
- 0-3 km storm-relative helicity
- -51 m²/s²
- Significant tornado parameter
- -0.8
- Supercell composite
- -5.8
The text
As transmitted.
722 WGUS64 KEWX 300834 FFAEWX URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Austin/San Antonio TX 334 AM CDT Fri Apr 30 2021 TXZ205>207-209-220>225-302300- /O.NEW.KEWX.FF.A.0001.210430T1200Z-210502T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Bexar-Comal-Guadalupe-Fayette-Atascosa-Wilson-Karnes-Gonzales- De Witt-Lavaca- Including the cities of San Antonio, New Braunfels, Seguin, La Grange, Pleasanton, Floresville, Karnes City, Gonzales, Cuero, and Hallettsville 334 AM CDT Fri Apr 30 2021 ...FLASH FLOOD WATCH IN EFFECT FROM 7 AM CDT THIS MORNING THROUGH SATURDAY EVENING... The National Weather Service in Austin/San Antonio has issued a * Flash Flood Watch for a portion of south central Texas, including the following areas, Atascosa, Bexar, Comal, De Witt, Fayette, Gonzales, Guadalupe, Karnes, Lavaca, and Wilson. * From 7 AM CDT this morning through Saturday evening * Rainfall amounts of 2-4 inches with isolated totals in excess of 6 inches will be possible. * The heavy rainfall could lead to flash flooding of creeks, streams, and low-water crossings. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
2 follow-up statements
653 WGUS64 KEWX 302000 FFAEWX URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Austin/San Antonio TX 300 PM CDT Fri Apr 30 2021 TXZ186>194-204-208-010400- /O.EXA.KEWX.FF.A.0001.000000T0000Z-210502T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Kerr-Bandera-Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee- Medina-Caldwell- Including the cities of Kerrville, Bandera, Fredericksburg, Boerne, Blanco, San Marcos, Austin, Bastrop, Giddings, Hondo, and Lockhart 300 PM CDT Fri Apr 30 2021 ...FLASH FLOOD WATCH IN EFFECT THROUGH SATURDAY EVENING... The National Weather Service in Austin/San Antonio has expanded the * Flash Flood Watch to include a portion of south central Texas, including the following areas, Bandera, Bastrop, Blanco, Caldwell, Gillespie, Hays, Kendall, Kerr, Lee, Medina, and Travis. * Through Saturday evening * Rainfall amounts of 2 to 5 inches are expected with isolated totals up to 8 inches possible. * The heavy rainfall could lead to flash flooding of creeks, streams, and low-water crossings. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ TXZ205>207-209-220>225-010400- /O.CON.KEWX.FF.A.0001.000000T0000Z-210502T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Bexar-Comal-Guadalupe-Fayette-Atascosa-Wilson-Karnes-Gonzales- De Witt-Lavaca- Including the cities of San Antonio, New Braunfels, Seguin, La Grange, Pleasanton, Floresville, Karnes City, Gonzales, Cuero, and Hallettsville 300 PM CDT Fri Apr 30 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SATURDAY EVENING... The Flash Flood Watch continues for * A portion of south central Texas, including the following areas, Atascosa, Bexar, Comal, De Witt, Fayette, Gonzales, Guadalupe, Karnes, Lavaca, and Wilson. * Through Saturday evening * Rainfall amounts of 2 to 5 inches are expected with isolated totals up to 8 inches possible. * The heavy rainfall could lead to flash flooding of creeks, streams, and low-water crossings. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
583 WGUS64 KEWX 010631 FFAEWX Flood Watch National Weather Service Austin/San Antonio TX 131 AM CDT Sat May 1 2021 TXZ186>194-204>209-220>225-020000- /O.CON.KEWX.FF.A.0001.000000T0000Z-210502T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Kerr-Bandera-Gillespie-Kendall-Blanco-Hays-Travis-Bastrop-Lee- Medina-Bexar-Comal-Guadalupe-Caldwell-Fayette-Atascosa-Wilson- Karnes-Gonzales-De Witt-Lavaca- Including the cities of Kerrville, Bandera, Fredericksburg, Boerne, Blanco, San Marcos, Austin, Bastrop, Giddings, Hondo, San Antonio, New Braunfels, Seguin, Lockhart, La Grange, Pleasanton, Floresville, Karnes City, Gonzales, Cuero, and Hallettsville 131 AM CDT Sat May 1 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING... The Flash Flood Watch continues for * A portion of south central Texas, including the following areas, Atascosa, Bandera, Bastrop, Bexar, Blanco, Caldwell, Comal, De Witt, Fayette, Gillespie, Gonzales, Guadalupe, Hays, Karnes, Kendall, Kerr, Lavaca, Lee, Medina, Travis, and Wilson. * Through this evening * Additional rainfall amounts of 1 to 4 inches are expected with isolated higher amounts possible. * The heavy rainfall could lead to flash flooding of creeks, streams, and low-water crossings. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Flash Flood Watch means that conditions may develop that lead to flash flooding. Flash flooding is a very dangerous situation. You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
The office that day
Everything else NWS Austin/San Antonio, TX issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 30, 11:25 AM CDT | Areal Flood Advisory | EWX | Atascosa | 3 hr |
| Apr 30, 4:53 PM CDT | Areal Flood Advisory | EWX | Bexar | 112 min |
| Apr 30, 5:48 PM CDT | Flash Flood Warning | EWX | Bexar | 6 hr |
| Apr 30, 6:52 PM CDT | Areal Flood Advisory | EWX | Comal | 69 min |
Nearby
Flash Flood Watches in Texas, 2021Every flash flood watch in 2021
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.