Alert archive / Arizona / Flash Flood Watches in 2021
Flash Flood Watch 6, NWS Phoenix, AZ
NWS Phoenix, AZ issued this flash flood watch at Aug 12, 2021, 1:30 PM MST for Gila County, Maricopa County, Pinal County, Arizona. It took effect at Aug 12, 2021, 5:00 PM MST. It was in force for 5 days.
The area
The counties it named.
The facts
- Issued
- Aug 12, 2021, 1:30 PM MST (20:30 UTC)
- In effect from
- Aug 12, 2021, 5:00 PM MST
- Expired
- Aug 17, 2021, 5:00 AM MST
- In force
- 5 days
- Issued by
- NWS Phoenix, AZ
- Flood severity
- None
Counties Gila County, AZ, Maricopa County, AZ, Pinal County, AZ
The radar
The Phoenix radar (KIWA), 13 km from the middle of the area, began a volume at 20:29 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.
The nearest sounding before it
Phoenix, AZ (KPSR), launched 12:00Z, 8.5 hours before the alert went out and 40 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
- 1266 J/kg
- Mixed-layer CIN
- -27 J/kg
- Mixed-layer LCL
- 865 m above ground
- 0-6 km bulk shear
- 9 kt
- 0-1 km storm-relative helicity
- 57 m²/s²
- 0-3 km storm-relative helicity
- 99 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
418 WGUS65 KPSR 122030 FFAPSR URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Phoenix AZ 130 PM MST Thu Aug 12 2021 AZZ534-537>563-131000- /O.NEW.KPSR.FF.A.0006.210813T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 130 PM MST Thu Aug 12 2021 ...FLASH FLOOD WATCH IN EFFECT FROM 5 PM MST THIS AFTERNOON THROUGH SUNDAY AFTERNOON... The National Weather Service in Phoenix has issued a * Flash Flood Watch for a portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * From 5 PM MST this afternoon through Sunday afternoon. * The threat for heavy rain will continue this afternoon and through the weekend. Above normal moisture levels are expected to persist and given the already saturated soils from antecedent rainfall, any showers or storms at this point will be capable of producing flash flooding with rain rates on average around 1-2 inches per hour (briefly higher at times), leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. Two time frames to watch with the potential for more scattered to widespread rainfall coverage will be Friday afternoon into Saturday morning and again on Sunday. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ SDB
9 follow-up statements
531 WGUS65 KPSR 130952 FFAPSR Flood Watch National Weather Service Phoenix AZ 252 AM MST Fri Aug 13 2021 AZZ534-537>563-132200- /O.CON.KPSR.FF.A.0006.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 252 AM MST Fri Aug 13 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Through Sunday afternoon. * The threat for heavy rain will continue through the weekend. High humidity levels will continue and several weather features will move through the region. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of average around 1-2 inches per hour (briefly higher at times), leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. Two time frames of particular concern are this evening into early Saturday and again on Sunday. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Iniguez
000 WGUS65 KPSR 132011 FFAPSR Flood Watch National Weather Service Phoenix AZ 111 PM MST Fri Aug 13 2021 AZZ534-537>563-141200- /O.CON.KPSR.FF.A.0006.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 111 PM MST Fri Aug 13 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Through Sunday afternoon. * The threat for heavy rain will continue through the weekend. High humidity levels will continue and several weather features will move through the region. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of average around 1-2 inches per hour (briefly higher at times), leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. Two time frames of particular concern are this evening into early Saturday and again on Sunday. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ INS
971 WGUS65 KPSR 140806 FFAPSR Flood Watch National Weather Service Phoenix AZ 106 AM MST Sat Aug 14 2021 AZZ534-537>563-151200- /O.CON.KPSR.FF.A.0006.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 106 AM MST Sat Aug 14 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Through Sunday afternoon. * The threat for heavy rain will continue through the weekend. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of up to 1-2 inches per hour (briefly higher at times), leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ Hirsch
514 WGUS65 KPSR 151022 FFAPSR Flood Watch National Weather Service Phoenix AZ 322 AM MST Sun Aug 15 2021 AZZ534-537>563-160000- /O.CON.KPSR.FF.A.0006.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 322 AM MST Sun Aug 15 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS AFTERNOON... The Flash Flood Watch continues for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Through this afternoon. * The threat for heavy rain will continue today. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of up to 1-2 inches per hour, leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ CK
762 WGUS65 KPSR 151942 FFAPSR URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Phoenix AZ 1242 PM MST Sun Aug 15 2021 AZZ534-537>563-161145- /O.EXT.KPSR.FF.A.0006.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley- Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa- South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior- Northwest Pinal County-West Pinal County- Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains- Pinal/Superstition Mountains-Sonoran Desert Natl Monument- San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- 1242 PM MST Sun Aug 15 2021 ...FLASH FLOOD WATCH NOW IN EFFECT THROUGH LATE MONDAY NIGHT... The Flash Flood Watch is now in effect for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert National Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, The East Valley of the Phoenix Metro Area, The Northwest Valley of the Phoenix Metro Area, Tonopah Desert, Tonto Basin, and West Pinal County. * Through late Monday night * The threat for heavy rain will continue today. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of up to 1-2 inches per hour, leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
784 WGUS65 KPSR 161031 FFAPSR Flood Watch National Weather Service Phoenix AZ 331 AM MST Mon Aug 16 2021 AZZ534-537>563-170000- /O.CON.KPSR.FF.A.0006.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 331 AM MST Mon Aug 16 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT... The Flash Flood Watch continues for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Through late tonight. * The threat for heavy rain will continue today. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of up to 1-2 inches per hour, leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ CK
131 WGUS65 KPSR 162348 FFAPSR Flood Watch National Weather Service Phoenix AZ 448 PM MST Mon Aug 16 2021 AZZ534-537>563-170900- /O.CON.KPSR.FF.A.0006.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 448 PM MST Mon Aug 16 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 2 AM MST TUESDAY... The Flash Flood Watch continues for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Until 2 AM MST Tuesday. * The threat for heavy rain will continue today. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of up to 1-2 inches per hour, leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ INS
291 WGUS65 KPSR 170352 FFAPSR URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Phoenix AZ 852 PM MST Mon Aug 16 2021 AZZ534-537>563-171200- /O.EXT.KPSR.FF.A.0006.000000T0000Z-210817T1200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 852 PM MST Mon Aug 16 2021 ...FLASH FLOOD WATCH NOW IN EFFECT UNTIL 5 AM MST TUESDAY... The Flash Flood Watch is now in effect for * A portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County. * Until 5 AM MST Tuesday. * The threat for heavy rain will continue tonight into the overnight hours on Tuesday. Given the already saturated soils from previous rainfall, any additional showers and thunderstorms will be capable of producing flash flooding with rain rates of up to 1-2 inches per hour, leading to rapid runoff into washes, small streams, and poor drainage areas. Flash flooding may also lead to river rises. Past and recent burn scars will be especially prone to flash flooding and debris flow. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ LJH
915 WGUS65 KPSR 171159 FFAPSR Flood Watch National Weather Service Phoenix AZ 459 AM MST Tue Aug 17 2021 AZZ534-537>563-171300- /O.EXP.KPSR.FF.A.0006.000000T0000Z-210817T1200Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Aguila Valley-Northwest Valley-Tonopah Desert-Gila Bend- Buckeye/Avondale-Cave Creek/New River-Deer Valley-Central Phoenix- North Phoenix/Glendale-New River Mesa-Scottsdale/Paradise Valley-Rio Verde/Salt River-East Valley-Fountain Hills/East Mesa-South Mountain/Ahwatukee-Southeast Valley/Queen Creek-Superior-Northwest Pinal County-West Pinal County-Apache Junction/Gold Canyon-Tonto Basin-Mazatzal Mountains-Pinal/Superstition Mountains-Sonoran Desert Natl Monument-San Carlos-Dripping Springs-Globe/Miami-Southeast Gila County- Including the cities of Hassayampa, Superior, Cashion, Gila Bend, Coolidge, Sunflower, Arlington, Circle City, Tonopah, Hayden, Gladden, Surprise, Gilbert, Goodyear, Sun City West, San Carlos, Kaka, Phoenix, Winkelman, Peoria, Beardsley, Apache Junction, Scottsdale, Wintersburg, Queen Creek, Sun Lakes, Tortilla Flat, Avondale, Peridot, Fountain Hills, Miami, Paradise Valley, Casa Grande, Liberty, Chandler, Mesa, Tempe, Globe, Cactus Forest, Punkin Center, Wickenburg, Sentinel, Aguila, Florence, and Wittmann 459 AM MST Tue Aug 17 2021 ...FLASH FLOOD WATCH WILL EXPIRE AT 5 AM MST EARLY THIS MORNING... The Flash Flood Watch for a portion of south central Arizona, including the following areas, Aguila Valley, Apache Junction/Gold Canyon, Buckeye/Avondale, Cave Creek/New River, Central Phoenix, Deer Valley, Dripping Springs, East Valley, Fountain Hills/East Mesa, Gila Bend, Globe/Miami, Mazatzal Mountains, New River Mesa, North Phoenix/Glendale, Northwest Pinal County, Northwest Valley, Pinal/Superstition Mountains, Rio Verde/Salt River, San Carlos, Scottsdale/Paradise Valley, Sonoran Desert Natl Monument, South Mountain/Ahwatukee, Southeast Gila County, Southeast Valley/Queen Creek, Superior, Tonopah Desert, Tonto Basin and West Pinal County will expire at 5 AM MST early this morning. The Flood Watch has ended, however numerous Flash Flood Warnings remain in effect from heavy rainfall last night. $$ 18
What forecasters said that day
The local office's own words before this flash flood watch went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood watch went out at Aug 12, 4:36 AM MST, 8 hours 54 minutes earlier.
Area forecast discussion, Aug 12, 4:36 AM MST, 8 hours 54 minutes before
Area Forecast Discussion National Weather Service Phoenix AZ 436 AM MST Thu Aug 12 2021 .UPDATE... Aviation discussion update. && .SYNOPSIS... High levels of moisture will remain entrenched across the region into early next week, leading to persistent chances for showers and thunderstorms. The primary threats with any storms remain localized heavy rainfall that may cause flash flooding. Strong winds and some blowing dust will also be possible for desert locations. With increased cloud cover and showers, temperatures will remain near to below normal. && .DISCUSSION... Overall a messy forecast across the region the next week as abundantly high levels of moisture remain in place and various lows of varying size influence our weather. A very moist environment is in place across our CWA. Surface dew points are in the mid 60s to low 70s. The 12.00Z KPSR sounding had boundary layer mixing ratios near 15 g/kg, which is right at the upper end of the climatology. The PWAT was 2.1", also at the upper ends of climatology for the first half of August. Upper air data, objective analysis, and satellite data depict the upper level low/vort max we've been watching currently circulating around Payson. Instability of 1000-1500 J/kg, mostly uncapped, is present currently across Maricopa and Pinal counties, so would not be surprised at all to see additional convective development at any point through this morning. Across the western CWA, a little more capping is in place but elevated instability is likely to be present so showers/storms can not be entirely ruled out there. Given the environment, of course locally heavy rain and flash flooding is the primary concern. The general pattern looks to remain a bit stagnant the next two days (and perhaps into early next week with a larger view) with a broad anti-cyclone over the Southwest US and the mid level vort max trapped and meandering around. Today is a bit of a tricky day. Most CAMs are interestingly quiet for much of the day, but there are hints of significant activity possible. Much will depend of course on how the morning plays out, but there is a continued low- end threat for mountain convection to translate into much of Maricopa/Pinal/La Paz counties tonight. Similar conditions are in place for Friday, with some (certainly not all) CAMs developing such a scenario again with possibly slightly stronger northwest mid-levels winds and shear in place. Even outside the diurnal cycle, temporally atypical convection will be possible. While the main threat is conditionally isolated heavy rains, can't discount more widespread strong winds and localized severe within wet downbursts. WPC has kept much of our eastern CWA within a MRGL category for flash flooding and SPC maintains a General TS in the outlooks the next few days. By early Saturday, the vort max overhead may be finally shearing out... only to be replaced by the next one arriving from the east. The continued presence of supporting weather features and the very high boundary layer moisture, which isn't going anywhere (GEFS mean boundary mixing ratios and PWAT remain AOA the 90th percentile through Tuesday), means rain/storm chances will continue right into early next week. Confidence in specifics within this pattern will drop each day and be highly dependent on day-to-day mesoscale features. Toward the middle/end of next week, ensembles point to a trough developing over the Pacific Northwest which will influence the upper level high currently over us. Various solutions are possible of course - ranging from a shallow and progressive trough across the northern Rockies which doesn't influence us much to a deeper trough that leads to more widespread rains. For now, the general forecast is for a gradual reduction in moisture and PoPs, though confidence in the extended forecast is rather low and carries a high spread. As far as temperatures - they will likely remain near to below normal through the next week. With the continued rain chances and debris clouds, Phoenix has the potential to go the entire next week without eclipsing the 100F mark. It has been fifty years (1971) since Phoenix has had an August with 10+ days of high temperatures below 100F (recently 2016 had eight and 2014 nine). With more sun likely, El Centro and Yuma will still be popping into the low 100s. Modestly cooler overnights will also help mitigate heat impacts, though elevated humidity will still make it challenging for those subjected to extended outdoor exposure. && .AVIATION...Updated at 1136Z. South-Central Arizona including KPHX, KIWA, KSDL, and KDVT: Area of showers/thunderstorms has generally pushed northeast of metro terminals, but can not rule out additional activity through the next few hours. Should additional activity develop, cigs and vsby may briefly drop into MVFR. After ~15Z, anticipate the rest of the morning and afternoon to be fairly quiet as the atmosphere settles. Later this evening (~02-06Z), potential continues for outflow winds from storms north of the metro to move through and possible trigger additional showers/storms. Given progressive nature of outflow, convective threat should subside after 06Z. However, given very moist/unstable environment, there is a 10-20% chance of redevelopment Thursday night into Friday morning. Southeast California/Southwest Arizona including KIPL and KBLH: Weak winds and fairly quiet weather through this afternoon expected. This evening, storms northeast of KBLH should send a strong outflow through the area. Gusts could exceed current levels in the TAF. In the Imperial Valley, light winds into the afternoon will be followed by stronger westerly downslope winds in the evening. && .FIRE WEATHER... Saturday through Wednesday: Generally an active weather period will continue with persistent chances for showers and thunderstorms, with the best chances across southern Gila county decreasing as you go west. Humidity values themselves will remain quite elevated during this period, with overnight values rising into the 50-90% range and daytime values falling only 25-45% range. Winds will favor typical diurnal/terrain influences most days. && .SPOTTER INFORMATION STATEMENT... Spotters should follow standard reporting procedures. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...None. CA...None. && DISCUSSION...Iniguez AVIATION...Iniguez FIRE WEATHER...Iniguez
In the hours before
Local storm report, Aug 12, 8:23 AM MST, 5 hours 7 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
823 AM MST THU AUG 12 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0615 AM FLASH FLOOD 9 N SAGUARO LAKE 33.69N 111.54W
08/12/2021 MARICOPA AZ MESONET
RAID 10 FOOT RISE IN SYCAMORE CREEK.
RAINFALL OVER THE BUSH FIRE BURN SCAR. DATA
SOURCE USGS STREAM GAGE.
&&
MSLocal storm report, Aug 12, 8:48 AM MST, 4 hours 42 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
848 AM MST THU AUG 12 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0530 PM FLASH FLOOD 12 ENE GILA BEND 32.99N 112.53W
08/11/2021 MARICOPA AZ DEPT OF HIGHWAYS
**DELAYED REPORT** STATE ROUTE 238 CLOSED
DUE TO FLASH FLOODING. LOCATION ESTIMATED
BASED ON AREA OF HEAVIEST RAINFALL ON RADAR
AND INFORMATION PROVIDED BY ADOT TWEET.
&&
MSLocal storm report, Aug 12, 9:03 AM MST, 4 hours 27 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
903 AM MST THU AUG 12 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0955 PM FLASH FLOOD 7 ESE BUCKEYE 33.33N 112.50W
08/11/2021 MARICOPA AZ MESONET
**DELAYED REPORT** ROAD CLOSURE DUE TO FLASH
FLOODING AT NARRAMORE ROAD DIP CROSSING.
TIMING FROM MARICOPA COUNTY FLOOD CONTROL
STREAM GAGE LOCATED ALONG WATERMAN WASH.
&&
MSLocal storm report, Aug 12, 9:54 AM MST, 3 hours 36 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
954 AM MST THU AUG 12 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0950 AM FLASH FLOOD 6 N DEER VALLEY 33.76N 112.12W
08/12/2021 MARICOPA AZ MESONET
ROAD CLOSURE DUE TO HIGH FLOWS IN SKUNK
CREEK. MARICOPA COUNTY FLOOD CONTROL STREAM
GAGE LOCATED UPSTREAM NEAR CAREFREE HIGHWAY
EXCEEDED ALARM STAGE. TIMING BASED ON TRAVEL
TIME INFORMATION PROVIDED BY MARICOPA COUNTY
FLOOD CONTROL.
&&
MSLocal storm report, Aug 12, 10:13 AM MST, 3 hours 17 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
1013 AM MST THU AUG 12 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM FLOOD 3 SE PUNKIN CENTER 33.83N 111.29W
08/12/2021 GILA AZ PUBLIC
FLOODING ALONG TONTO CREEK IN TONTO BASIN
AREA. EVACUATIONS OF LAZY JR RV PARK
REPORTED ON SOCIAL MEDIA. HIGH FLOWS ALONG
TONTO CREEK NOTED FROM CAMERA IMAGE PROVIDED
BY SRP.
&&
MSLocal storm report, Aug 12, 10:30 AM MST, 3 hours before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
1030 AM MST THU AUG 12 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0645 AM FLASH FLOOD 1 SSW CAVE CREEK 33.82N 111.97W
08/12/2021 MARICOPA AZ MESONET
LOW WATER CROSSINGS ALONG CAVE CREEK
UPSTREAM OF CAREFREE HIGHWAY FLOODED. DATA
FROM MARICOPA COUNTY FLOOD CONTROL STREAM
GAGE ALONG CAVE CREEK LOCATED UPSTREAM OF
LOW WATER CROSSINGS. STREAM GAGE EXCEEDED
COUNTY SET ALARM STAGE.
&&
MSThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 5:03 PM MST | Severe Thunderstorm Warning | PSR | Maricopa | 42 min |
| Aug 11, 5:14 PM MST | Flash Flood Warning | PSR | Maricopa | 3 hr |
| Aug 11, 5:14 PM MST | Special Weather Statement | PSR | Maricopa | 46 min |
| Aug 11, 5:30 PM MST | Flash Flood Warning | PSR | Maricopa | 2 hr |
| Aug 11, 5:30 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 45 min |
| Aug 11, 5:39 PM MST | Flash Flood Warning | PSR | Maricopa | 3 hr |
| Aug 11, 5:49 PM MST | Special Weather Statement | PSR | 41 min | |
| Aug 11, 5:57 PM MST | Flash Flood Warning | PSR | Maricopa | 6 hr |
| Aug 11, 6:07 PM MST | Dust Storm Warning | PSR | Maricopa, Pinal | 53 min |
| Aug 11, 6:12 PM MST | Severe Thunderstorm Warning | PSR | Maricopa, Pinal | 48 min |
| Aug 11, 6:19 PM MST | Severe Thunderstorm Warning | PSR | Maricopa | 41 min |
| Aug 11, 6:20 PM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 11, 6:40 PM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 11, 7:02 PM MST | Special Weather Statement | PSR | 58 min | |
| Aug 11, 7:11 PM MST | Special Weather Statement | PSR | 64 min | |
| Aug 11, 7:26 PM MST | Flash Flood Warning | PSR | La Paz | 3 hr |
| Aug 11, 7:53 PM MST | Special Weather Statement | PSR | La Paz | 37 min |
| Aug 12, 2:00 AM MST | Special Weather Statement | PSR | 45 min | |
| Aug 12, 2:42 AM MST | Flash Flood Warning | PSR | Gila, Maricopa | 4 hr |
| Aug 12, 2:45 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 12, 3:34 AM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 12, 4:16 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 4:33 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 5:17 AM MST | Flash Flood Warning | PSR | Maricopa | 6 hr |
| Aug 12, 6:04 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 6:21 AM MST | Areal Flood Advisory | PSR | Maricopa | 46 min |
| Aug 12, 7:00 AM MST | Flash Flood Warning | PSR | Maricopa | 4 hr |
| Aug 12, 10:09 AM MST | Areal Flood Warning | PSR | Gila | 8 hr |
| Aug 12, 10:46 AM MST | Areal Flood Warning | PSR | Maricopa | 15 hr |
| Aug 12, 2:11 PM MST | Special Weather Statement | PSR | La Paz | 34 min |
| Aug 12, 2:30 PM MST | Areal Flood Advisory | PSR | Maricopa | 3 hr |
| Aug 12, 2:45 PM MST | Areal Flood Advisory | PSR | La Paz | 3 hr |
| Aug 12, 2:54 PM MST | Flash Flood Warning | PSR | La Paz, Maricopa | 4 hr |
| Aug 12, 3:11 PM MST | Flash Flood Warning | PSR | Maricopa | 5 hr |
| Aug 12, 3:34 PM MST | Special Weather Statement | PSR | 41 min | |
| Aug 12, 4:14 PM MST | Areal Flood Advisory | PSR | Maricopa, Yuma | 3 hr |
Nearby
Flash Flood Watches in Arizona, 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.