Alert archive / Arizona / Flash Flood Watches in 2021
Flash Flood Watch 5, NWS Tucson, AZ
NWS Tucson, AZ issued this flash flood watch at Aug 12, 2021, 11:48 AM MST for 6 counties in Arizona. It took effect at Aug 12, 2021, 12:00 PM MST. It was in force for 5 days.
The area
The counties it named.
The facts
- Issued
- Aug 12, 2021, 11:48 AM MST (18:48 UTC)
- In effect from
- Aug 12, 2021, 12:00 PM MST
- Expired
- Aug 17, 2021, 2:00 AM MST
- In force
- 5 days
- Issued by
- NWS Tucson, AZ
- Flood severity
- None
Counties Cochise County, AZ, Graham County, AZ, Greenlee County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ
The radar
The Tucson radar (KEMX), 61 km from the middle of the area, began a volume at 18:43 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
Tuscon, AZ (KTUS), launched 12:00Z, 6.8 hours before the alert went out and 49 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
- 148 J/kg
- Mixed-layer CIN
- -88 J/kg
- Mixed-layer LCL
- 1043 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- -2 m²/s²
- 0-3 km storm-relative helicity
- -1 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
633 WGUS65 KTWC 121848 FFATWC URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Tucson AZ 1148 AM MST Thu Aug 12 2021 AZZ501>515-131845- /O.NEW.KTWC.FF.A.0005.210812T1900Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 1148 AM MST Thu Aug 12 2021 ...FLASH FLOOD WATCH IN EFFECT NOW THROUGH SUNDAY AFTERNOON... The National Weather Service in Tucson has issued a * Flash Flood Watch for a portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through Sunday afternoon. * The threat for heavy rain increases this afternoon from Tucson south and east to the International Border. The threat then expands to all of southeastern Arizona by Friday. Two time frames to watch will be Friday evening into Saturday morning and again later Saturday into Sunday. Valley locations could see 1 to 3 inches of rain with the mountains 3 to 6 inches of rain by the end of the event Sunday. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ JRM
11 follow-up statements
146 WGUS65 KTWC 131240 FFATWC Flood Watch National Weather Service Tucson AZ 540 AM MST Fri Aug 13 2021 AZZ501>515-140000- /O.CON.KTWC.FF.A.0005.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 540 AM MST Fri Aug 13 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through Sunday afternoon. * The threat for heavy rain will be expanding across southeast Arizona later today. Two time frames to watch will be this evening into Saturday morning and again later Saturday into Sunday. Valley locations could see 1 to 3 inches of rain with the mountains 3 to 6 inches of rain by the end of the event Sunday. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
171 WGUS65 KTWC 132117 FFATWC Flood Watch National Weather Service Tucson AZ 217 PM MST Fri Aug 13 2021 AZZ501>515-141200- /O.CON.KTWC.FF.A.0005.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 217 PM MST Fri Aug 13 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through Sunday afternoon. * The threat for heavy rain will be expanding across southeast Arizona later today. Two time frames to watch will be this evening into Saturday morning and again later Saturday into Sunday. Valley locations could see 1 to 3 inches of rain with the mountains 3 to 6 inches of rain by the end of the event Sunday. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ AH
179 WGUS65 KTWC 141012 FFATWC Flood Watch National Weather Service Tucson AZ 312 AM MST Sat Aug 14 2021 AZZ501>515-142300- /O.CON.KTWC.FF.A.0005.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 312 AM MST Sat Aug 14 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through Sunday afternoon. * The threat for heavy rain will continue across southeast Arizona today into Sunday. Valley locations could see 1 to 3 inches of rain with the mountains 3 to 6 inches of rain by the end of the event Sunday. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
592 WGUS65 KTWC 142248 FFATWC Flood Watch National Weather Service Tucson AZ 348 PM MST Sat Aug 14 2021 AZZ501>515-151100- /O.CON.KTWC.FF.A.0005.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 348 PM MST Sat Aug 14 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH SUNDAY AFTERNOON... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through Sunday afternoon. * The threat for heavy rain will continue across southeast Arizona today into Sunday. Valley locations could see 1 to 3 inches of rain with the mountains 3 to 6 inches of rain by the end of the event Sunday. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ KRG
564 WGUS65 KTWC 150929 FFATWC Flood Watch National Weather Service Tucson AZ 229 AM MST Sun Aug 15 2021 AZZ501>515-151730- /O.CON.KTWC.FF.A.0005.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 229 AM MST Sun Aug 15 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS AFTERNOON... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through this afternoon. * The threat for heavy rain will continue across southeast Arizona today although the areal coverage will be less than previous days. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
685 WGUS65 KTWC 151545 FFATWC Flood Watch National Weather Service Tucson AZ 845 AM MST Sun Aug 15 2021 AZZ501>515-160000- /O.CON.KTWC.FF.A.0005.000000T0000Z-210816T0000Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 845 AM MST Sun Aug 15 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 5 PM MST THIS AFTERNOON... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Until 5 PM MST this afternoon. * The threat for heavy rain will continue across southeast Arizona today although the areal coverage will be less than previous days. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ GL
973 WGUS65 KTWC 152056 FFATWC URGENT - IMMEDIATE BROADCAST REQUESTED Flood Watch National Weather Service Tucson AZ 156 PM MST Sun Aug 15 2021 AZZ501>515-161100- /O.EXT.KTWC.FF.A.0005.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 156 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 Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through late Monday night. * The threat for heavy rain will continue across southeast Arizona into this evening with somewhat limited areal coverage. A much more widespread heavy rain threat is expected Monday afternoon through Monday evening. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ GL
537 WGUS65 KTWC 161014 FFATWC Flood Watch National Weather Service Tucson AZ 314 AM MST Mon Aug 16 2021 AZZ501>515-162300- /O.CON.KTWC.FF.A.0005.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 314 AM MST Mon Aug 16 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through late tonight. * The threat for heavy rain will increase this afternoon into this evening across southeast Arizona as showers and thunderstorms move across the area. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$
150 WGUS65 KTWC 161945 FFATWC Flood Watch National Weather Service Tucson AZ 1245 PM MST Mon Aug 16 2021 AZZ501>515-170345- /O.CON.KTWC.FF.A.0005.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 1245 PM MST Mon Aug 16 2021 ...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH LATE TONIGHT... The Flash Flood Watch continues for * A portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Through late tonight. * The threat for heavy rain will continue this afternoon into this evening across southeast Arizona as showers and thunderstorms move across the area. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ GL
273 WGUS65 KTWC 170315 FFATWC Flood Watch National Weather Service Tucson AZ 815 PM MST Mon Aug 16 2021 AZZ501>515-170900- /O.CON.KTWC.FF.A.0005.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 815 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 Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties. * Until 2 AM MST Tuesday. * The threat for heavy rain will continue this afternoon into this evening across southeast Arizona as showers and thunderstorms move across the area. * Locally heavy rainfall combined with a saturated ground will likely result in flash flooding of washes, small streams, and poor drainage areas. Burn scars from past and more recent wildfires will be especially prone to flash flooding and debris flow. Flash flooding may also lead to significant mainstem river rises that could linger into Sunday and Monday. This may result in some washes and rivers reaching flood stage. PRECAUTIONARY/PREPAREDNESS ACTIONS... You should monitor later forecasts and be prepared to take action should Flash Flood Warnings be issued. && $$ RH
860 WGUS65 KTWC 170852 FFATWC Flood Watch National Weather Service Tucson AZ 152 AM MST Tue Aug 17 2021 AZZ501>515-171000- /O.EXP.KTWC.FF.A.0005.000000T0000Z-210817T0900Z/ /00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/ Western Pima County-Tohono O'odham Nation-Upper Santa Cruz River Valley/Altar Valley-Tucson Metro Area-South Central Pinal County- Southeast Pinal County-Upper San Pedro River Valley-Eastern Cochise County below 5000 feet-Upper Gila River Valley-White Mountains of Graham and Greenlee Counties-Galiuro and Pinaleno Mountains- Chiricahua Mountains-Dragoon and Mule and Huachuca and Santa Rita Mountains-Catalina and Rincon Mountains-Baboquivari Mountains- Including the cities of Sierra Vista, Mount Lemmon, Douglas, Mount Graham, Ajo, Chiricahua NM, Marana, Willcox, Summerhaven, Canelo Hills, Benson, Nogales, Picacho Peak State Park, Kitt Peak, Tucson, Mammoth, Madera Canyon, Oracle, Safford, Bisbee, Vail, Clifton, Organ Pipe Cactus N.M., Hannagan Meadow, Sells, and Green Valley 152 AM MST Tue Aug 17 2021 ...FLASH FLOOD WATCH WILL EXPIRE AT 2 AM MST EARLY THIS MORNING... The Flash Flood Watch for a portion of Southeast Arizona, including the following areas, Baboquivari Mountains, Catalina and Rincon Mountains, Chiricahua Mountains, Dragoon and Mule and Huachuca and Santa Rita Mountains, Eastern Cochise County below 5000 feet, Galiuro and Pinaleno Mountains, South Central Pinal County, Southeast Pinal County, Tohono O'odham Nation, Tucson Metro Area, Upper Gila River Valley, Upper San Pedro River Valley, Upper Santa Cruz River Valley/Altar Valley, Western Pima County and White Mountains of Graham and Greenlee Counties will expire at 2 AM MST early this morning. Flooding is no longer expected to pose a threat for most of southeast Arizona. Please continue to heed remaining road closures. $$
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 Tucson, AZ wrote its last area forecast discussion before this flash flood watch went out at Aug 12, 10:01 AM MST, 1 hour 47 minutes earlier.
Area forecast discussion, Aug 12, 10:01 AM MST, 1 hour 47 minutes before
Area Forecast Discussion National Weather Service Tucson AZ 1001 AM MST Thu Aug 12 2021 .SYNOPSIS...Another chance of thunderstorms today. A disturbance moving in from the east Friday into the weekend will increase convection for much of southeast Arizona. Some storms will generate strong winds and heavy rain which will result in continued flooding concerns and localized storm damage. && .DISCUSSION...The current forecast for today remains on track, therefore no changes are expected at this time. Current satellite imagery shows mainly clear skies across much of SEAZ. This will allow for ample heating sufficient for shower and thunderstorm development by late morning and into early afternoon. Something to watch will be a weak low/MCV that formed overnight west of Phoenix. This is expected to slowly drift south today into tonight. This will likely have some influence on our weather this afternoon and could spread some activity into the Tucson Metro. Areas with the greatest chance for showers/storms and possible flash flooding will be primarily be from Tucson south and east with Santa Cruz County seeing the highest probabilities. There is some indication thunderstorms will persist into the overnight, however confidence is low to moderate. We will keep an eye on this and give an update later this afternoon. NOTE - Friday night through Sunday afternoon will see an enhanced threat for flash flooding. More on that this afternoon. && .AVIATION...Valid through 13/18Z. Mostly SCT-BKN clouds 10-14k ft MSL. Isolated to scattered SHRA/TSRA. Local MVFR conditions and gusty winds with SHRA/TSRA. Outside of SHRA/TSRA, SFC winds will be less than 10 kts following a normal diurnal flow of sly/sely during the night/early morning and mainly wly/nwly late morning through afternoon. Aviation discussion not updated for TAF amendments. && .FIRE WEATHER...Ample moisture this week along with periodic mid level disturbances will result in at least a mid grade monsoon pattern. Given the higher levels of moisture and cloud coverage, temperatures will be cooler this week. Strong, erratic winds and locally heavy rainfall will be possible with any stronger storms that develop. 20-foot winds will generally be less than 15 mph when not influenced by thunderstorms. && .PREV DISCUSSION... /issued 314 AM MST Thu Aug 12 2021/ Plenty of moisture and instability in place for another chance of thunderstorms today with possible outflow from the eastern mountains overnight. Up next, we're seeing increasing confidence in another inverted trough scenario this weekend. As the current high east of the area breaks down under the broad trough digging into the Midwest, A strong ridge will develop through the Great Basin with a new high center consolidating over Nevada and Utah. The resulting easterly flow across SE AZ will do 2 things. First, it will make for favorable conditions for strong organized outflow from the Mogollon Rim through eastern areas and into the lower deserts. Second, a strong mid level impulse is developing through west Texas and eastern New Mexico. Ensembles build this into a strong inverted trough that subsequently pushes into Southeast Arizona from the east by Saturday morning. Ahead of this feature we could see enhanced chances for severe storms tomorrow along with the potential outflow from the eastern mountains into the lower deserts. Then, Friday night through Sunday we'll see periods of showers and thunderstorms over wide areas with enhanced threat of flooding and flash flooding. Depending on timing after that, we could still see some storm enhancement as late as Monday. Then, there are some hints that a drier southwesterly flow could slow things down for a few days by the middle of next week. && .TWC WATCHES/WARNINGS/ADVISORIES...None. && Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson
The office that day
Everything else NWS Tucson, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 11, 11:52 PM MST | Special Weather Statement | TWC | 38 min | |
| Aug 12, 12:06 AM MST | Flash Flood Warning | TWC | Pima | 103 min |
| Aug 12, 12:37 AM MST | Areal Flood Advisory | TWC | Pima | 113 min |
| Aug 12, 1:49 AM MST | Areal Flood Advisory | TWC | Pima | 116 min |
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.