The following events were reported: Flash Flood, Hail, Thunderstorm Wind. These occurred near station USW00023183, approximately 26.0246 km away, between 2021-08-18 13:00:00 and 2021-08-18 21:10:00. The events included records with hailstones measuring 44.67857142857143 inches.Thankfully, no injuries or fatalities were reported. The events caused property damage valued at 55000.0 and crop damage of 0.0. Episode Narrative: An upper level trough and lead-on shortwave trough moved through Arizona during the day on the 18th. Moderate to high instability and high moisture content supported scattered strong thunderstorms. With deep south to southwest upslope flow, storms favored the foothills and mountainous areas of Maricopa and Gila counties. Most storms were producing at least 1 to 2 inch per hour rain rates, with several storms producing 2 to 3 inch rates and at times higher. Back-building and training of storms over the same areas resulted in significant to catastrophic flash flooding. A few burn scars experienced flash flooding, including the recent Telegraph burn area which had catastrophic flooding of the Russell Gulch drainage. There were also 2 fatalities on this day with off-roaders recreating near Camp Creek in northeast Maricopa County. The strong to severe storms also produced damaging winds from microbursts and small hail over lower desert locations. An upper level trough and lead-on shortwave trough moved through Arizona during the day on the 18th. Event Narrative: Arizona Department of Transportation reported State Route 238 was closed for several hours between mile posts 35 and 40 due to flooding. Timing of impacts based on radar. No damages or injuries were reported. Videos show significant floodwaters in Galloway Wash with flow across Spur Cross Road, making the road impassable to all traffic. Measured and radar estimated rainfall amounts were around 2 to 4 inches in 2 to 3 hours over areas upstream of this location. Timing adjusted based on radar. A large tree, possibly a palm tree, was blown down onto power lines along Extension Road between 2nd Street and 2nd Place, causing a power outage to approximately 600 customers. Winds estimated around 55 to 65 mph. Timing based on radar. No injuries were reported. Pictures on social media show multiple snapped tree due to strong downburst winds. Wind speeds estimated around 55 to 60 mph. A Maricopa County Flood Control District stream gage along Cave Creek at Cactus Road recorded flow climbing above alarm stage, impacting nearby low-lying areas. At 1632MST, the gage crested at 11.14 feet and 1,567 CFS. No damage or injuries were reported. FCDMC STREAM GAUGE||A Maricopa County Flood Control District stream gage located along Indian Bend Wash at Shea Boulevard exceeded alarm stage, resulting in impacts to downstream low water crossings as well as to the Indian Bend Wash greenbelt. At 1501MST, flow in Indian Bend Wash crested at 3.02 feet and 2031 CFS. According to a nearby mPING report close to Paradise Valley Mall, a flooded street led to a vehicle becoming stranded. A portion of the roof of an apartment complex near 7th Avenue and Hatcher Road was torn of in strong winds and landed on an unoccupied parked car, causing damage. Nearby, multiple photos on social media showed several downed saguaros with one of them causing some damage to the front of a home near 12th Street and Northern Avenue. Winds estimated around 60 to 65 mph. Numerous trees down across Ahwatukee with many along Desert Foothills Parkway and Chandler Boulevard over to Ray Road. Many of the trees were palo verdes and several fell into roads and impeded traffic. Winds estimated around 50 to 60 mph. Time based on radar. Broadcast media coverage showed significant flow in East Fork Cave Creek leading to the closure of 7th Avenue near Coral Gables Street. A Flood Control District of Maricopa County streamflow gage a few hundred feet upstream from 7th Avenue exceeded alarm stage at 1422MST, crested at 3.66 feet at 1509MST, and fell back below alarm stage at 1645MST. A man tested the floodwaters with his unicycle, but wisely turned around. Videos from a local TV station showed deep, swiftly moving water flowing in a wash across an unbridged crossing along 7th Avenue near Coral Gables Drive in Moon Valley. Nearby, Greenway Road was closed at I-17 due to flooding. A Maricopa County Flood Control District stream gage along Cave Creek north of Carefree Highway exceeded bank full stage, impacting downstream low water crossings. At 1502MST, the creek crested at 7.65 feet and 5178 CFS. Significant flow in a typically dry wash made Carefree Highway between Tom Darlington Drive and Stagecoach Pass impassable to all traffic. There was also a photo that showed a lot of mud and gravel in one of the southbound lanes of Tom Darlington Drive near Meander Way. Both of these were reported around 1550PM. Very heavy rain began over the area and just upstream closer to 1300MST, with measured and radar estimated rainfall amounts of 2 to 4 inches in 1 hour. Timing of impacts adjusted based on radar. Multiple large trees uprooted in the area of 19th Ave between Missouri Ave and Maryland with some trees falling into and blocking streets. One tree was 30 feet tall and had a 12-18 inch diameter trunk. A large tree also reportedly fell at Palo Verde golf course. Timing was based on radar and wind gusts were estimated up to 50-60 mph with downburst signatures evident on radar. Multiple reports of wind damage from a microburst along Peoria Avenue between 35th and 43rd Avenues. A couple large pine trees fell on an apartment complex, causing damage to the edge of the roof. A tree fell on 2 unoccupied parked cars at another apartment complex, causing major damage. A 1-foot diameter tree fell on an unoccupied parked car at a business plaza. There was also a partial roof torn off reported in the area. Winds were estimated around 60 to 65 mph.