Not a moment too monsoon: ’17 rainy season was uneventful
You could look at the curve of the 2017 Arizona monsoon as a pretty uninteresting roller coaster.
After a flat start in June, we started heading uphill in late July. After a little dip to end the month, we headed back up to reach a peak in the first half of August. After that, the ride was pretty much over as we coasted through the end of August and all of September with hardly a drop of rain. October weather chart: Find it in print Sunday or at weather.azcentral.com.
The last measurable rain in Phoenix was .06 inches on Aug. 23.
The rain gauge at Phoenix Sky Harbor International Airport, the city’s official reporting station, registered 2.32 inches of rain for the period of June 15 through Sept. 30. That’s the span designated as the official monsoon season by the National Weather Service.
That 2.32-inch total is 0.39 inches below normal for the season and ranks as the 62nd-wettest in the 122-year period of record, according to the National Weather Service.
“I think one of the big take-homes for this monsoon is most of the action happened in a couple of weeks in July,” University of Arizona climatologist Mike Crimmins said. “For most of the state it’s been pretty quiet for much of August, which is unusual, and almost all of September as well.”
The airport rain gauge doesn’t tell the entire story of the 2017 monsoon. Other parts of the Valley saw considerably more rain than central Phoenix this summer.
The gauge at the Mesa fire station near Power and McDowell roads recorded 5.08 inches, and a reporting station at Wolverine Pass (just north of Apache Junction) picked up 6.1 inches.
On the west side, a station at Bullard Wash at Indian School Road recorded 4.29 inches, while the gauge at Glendale City Hall showed 3.46 inches.
Even some stations relatively close to the airport recorded more rain. A gauge at Perry Park (near 32nd Street and Indian School Road) registered 3.58 inches, while one at the Salt River and Priest Drive recorded 3.27 inches.
The season was a mixed bag throughout the state as well. Through Sept. 29, Yuma recorded 0.54 inches of rain. Normal there is 1.24 inches. Flagstaff saw 8.36 inches, 0.05 inches above average. Kingman was above average with 5.08 inches; its average is 2.82 inches.
Tucson was the big winner, tallying 8.57 inches compared with a normal 6.08 inches. But 6.8 inches of Tucson’s rain came from a few storms in July.
“(Tucson) won the monsoon early and didn’t do anything else for the whole thing,” Crimmins said. “By the end of July, for Tucson, we had our seasonal total. Then we had one other big event that put us over 8 inches the second week of August, and that’s been about it.”
State climatologist Nancy Selover said the somewhat disappointing Pacific hurricane season is a likely contributor to the slow end to the monsoon. Average rainfall for September in Phoenix is 0.64 inches, and often, moisture from the remnants of Pacific hurricanes makes it to the state to pad that total. Through Friday, there was no measurable rain at Sky Harbor in September, and the forecast for today does not call for rain.
The disappointing totals haven’t done much to help Phoenix make up its rainfall deficit for the year. Through September, the city has had 4.73 inches of rain, 1.19 inches below normal.
“It hasn’t been a great monsoon,” Selover said.