According to the National Weather Service, as of Friday, Flagstaff Pulliam Airport had recorded 15.31 inches of precipitation for the year; the normal expectation for the year is only slightly higher at 15.32.
The measurement’s virtual equivalence underscores Flagstaff's particularly wet monsoon season. However, other cities in Arizona like Page and Williams are both inches under their normal measurements for the year and still in drought conditions.
Page’s dry winter has left it with 3.50 inches of precipitation, well under the city's normal average of 5.67. While Williams made up more of its inch totals during the monsoon season like Flagstaff did, the city did not get enough to bring its 12.83 inches to the normal 16.04. Williams’ winter only received 4.47 inches of precipitation -- its norm is 12.12.
On paper the monsoonal rain made up for the Flagstaff winter precipitation totals, but the snow plays a special place in the environment. Justin Johndrow, lead forecaster at the National Weather Service, said snow saturates the ground, helping vegetation and reservoirs.
“[The winter] is when we get a lot of the precipitation that soaks in deep to help the reservoirs,” Johndrow said. “Once you miss that, it’s hard to catch up with rain from the monsoon season.”
The weather service calculates their “normal” number once a decade. At that point, they create an average for the past 30 years and end up with their normal estimations for precipitation. That being said, given Flagstaff’s unpredictable weather patterns, the normal number isn’t exactly what should be expected in a given year.
For instance, the normal number would tell you that 101.7 inches is the average amount of snowfall over the past year.
“There will be a lot of years where it’s 140 inches and some years where it’s 50 inches,” Johndrow said. “A lot of years are pretty variable.”
After the snowfall melts down, it may only deliver a fragment of its inch count.
This year the Flagstaff winter had a dry start, only delivering a hundredth of an inch of rain at Flagstaff Pulliam Airport between Oct. 1, 2017 and Jan. 8, 2018. The weather service stops considering weather patterns within the winter season after March 31. At that point the city had received 50 percent less precipitation than the normal rate of 5.02 inches, the equivalent of slightly over 37 inches of snow.
The normal amount of precipitation for the city by March is 11.62 inches.
With the heavy monsoon season almost behind us and October fast approaching, the city has just about reached the normal number of rain for the year. From June 15 through Friday, the city has received 9.62 inches of rain while the normal total is 7.06.
As the seasons change and the start of winter is on the horizon, Johndrow said Flagstaff could be seeing its first freeze in as soon as two weeks or as late as a month. Bellemont and the Fort Valley area in Flagstaff both reached 32 degrees on Thursday, while Flagstaff hit 37 degrees.
Page’s low has been much warmer at a little under 60 degrees; Williams was close to 40 degrees on Sept. 4.