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Trusted local news leader for Prescott area communities since 1882
1:41 AM Wed, Nov. 14th

Monsoon season goes out with a bang

Several homes in the Groom Creek area south of Prescott were damaged by Saturday’s final monsoon storm of the season. (Yavapai County Development Services Department/Courtesy photo)

Several homes in the Groom Creek area south of Prescott were damaged by Saturday’s final monsoon storm of the season. (Yavapai County Development Services Department/Courtesy photo)

Prescott set a record this year for total monsoon precipitation with 18.23 inches of rain, nearly reaching the city's annual average of 18.78 inches in just three months.

The long-term average precipitation for Prescott's July-September monsoon is 7.75 inches. City records date back to 1898. The official National Weather Service site is located at the Sundog wastewater treatment plant on the northeast side of the city.

Nearly all of northern Arizona saw above-average monsoon rainfall in July-September.

In Yavapai County, Chino Valley and Castle Hot Springs recorded their second-wettest monsoons. Chino received 10.96 inches and records there date back to 1941. Castle Hot Springs, on the southern border of the county, registered 10.5 inches and its records date to 1916.

Bagdad saw its third-wettest monsoon on record with 9.98 inches. Records there date to 1925.

And Jerome recorded its 5th wettest monsoon with 13.08 inches, where records date to 1897.

Confirming the variability of monsoon rains, the Prescott airport recorded only half of what the Prescott Sundog site recorded six miles to the south. The airport registered 9.09 inches, making it the 9th wettest monsoon in airport records dating to 1948.

While the airport is located in naturally drier grasslands, sites in Prescott's mountainous areas recorded even more rain than Sundog, which is located in the transitional zone between the mountains and grasslands.

A Yavapai County Flood Control District measuring site on Banning Creek just south of downtown Prescott recorded 20.04 inches, while Granite Creek at White Spar Campground on the southern edge of Prescott recorded 19.88 inches, noted Justin Johndrow of the National Weather Service office in Flagstaff.

Prescott's Sundog site registered 4.87 inches of rain in July (average is 2.87), 8.31 inches in August (average 3.18), and 5.05 inches in September (average is 1.70).

The combined 18.23 inches for Prescott's monsoon broke the previous record of 17.84 inches set in 1983. This is the only year in the ongoing 16-year drought that has made the Top 5 list for the city. The top 5 list also includes 16.40 inches in 1984, 14.93 inches in 1971 and 13.75 inches in 1958.

Several tropical storm systems leftover from Pacific hurricanes helped push up Prescott's rainfall numbers, but not always. It was the only city in northern Arizona to set an all-time record for monsoon moisture this year.

"It just happened to be moist, and the Prescott area just happened to be the place this time," Johndrow said.

The heaviest single day of rain in Prescott occurred on Aug. 19 when 2.52 inches fell at Sundog. But that was nothing compared to the 5-6 inches that fell that day in the southern part of the county and in Maricopa County, where severe flooding occurred. A Black Canyon City mobile home park was evacuated and a few of the residences were damaged.

Saturday's monsoon-ending storm probably wreaked the most havoc of any monsoon storms in the Prescott area this year. The Prescott airport set a new record for single-day rainfall that day with 1.36 inches, breaking the old record of 0.87 inches set in 1977.

Prescott Fire Department personnel rescued a woman from the raging Granite Creek in downtown Prescott Saturday as water flooded into downtown businesses. The creek was running at 3,900 cfs and rose to a height of more than 11 feet at 3:45 p.m.

About six miles south of the city in the Groom Creek area that same day, an odd weather event snapped hundreds of ponderosa pine trees on the Prescott National Forest and damaged more than a dozen homes. Weather Service experts are trying to determine if it was a tornado or some sort of downdraft.

Three homes were severely damaged, but no one was home, said Steve Mauk, Yavapai County Development Services director. He and other county officials surveyed the damage.

"Luckily no one got hurt," Mauk said. "There was a sun room that got taken completely out by trees." A second home lost its metal roof in the winds, and third was damaged by a tree. All were located on top of a hill, he said.

The Yavapai County Jeep Posse and a forest patrol supervisor went door to door to check for any injuries.

Follow Joanna Dodder on Twitter @joannadodder.