How wacky is this spring’s weather?
It depends on what you measure.
At least by some measures, it’s off-the-charts loony, but by others, it’s a fairly conventional season.
Cortez weather watcher Jim Andrus reports that the 3.5 inches of snow recorded in town – coming in two waves, 2.5 inches from 9:45 a.m. to 1 p.m. Monday and another inch from 2 a.m. to 3:30 a.m. Tuesday – amount to 3,500% of normal May snowfall for Cortez.
Cortez’s normal snowfall for the month is 0.1 inch.
“I don’t remember snow in May in Cortez in the 20 years I’ve been keeping records,” Andrus said. “Our long-term average is one-tenth of an inch, so obviously we’re having an unusual month.”
So far in May, Cortez has received 1.27 inches of precipitation compared with a total monthly average of 0.83 inches, so already May 2019 has received 153% of average precipitation with 10 days still available to boost the numbers.
But temperatures this spring are adhering more closely to seasonal norms, although May is shaping up to be cooler than normal.
According to the National Weather Service in Grand Junction, Cortez’s temperatures in March tracked at normal, April was 1.6 degrees above normal, and, so far, May is 1.9 degrees below normal.
“The spring may feel cooler than normal because of May,” said weather service meteorologist Erin Walter. “But for Cortez, March was right on normal, and April was a bit warmer than normal.”
This spring also might seem cooler than normal because last spring was much warmer than normal, Walter said.
Last year in Cortez, average March temperatures were 0.2 degree warmer than normal, average April temperatures were 3.1 degrees above normal, and May’s temperatures were 3.5 degrees above normal.
“Last May, Cortez had well-above-average temperatures, and this May it’s well-below, so in comparison it seems really cold, but the temperatures this spring aren’t really too unusual,” Walter said.
Andrus said May temperatures can vary more widely from year to year.
“May is really a battleground month between summer and winter. Summer wants to take over, but winter is going to put up a battle,” he said.
While this May has been cooler than average, Walter said one month or even one year of below-average temperatures doesn’t mean a whole lot in the context of climate change.
“Climate change isn’t a linear pattern. It’s complex. There is still a possibility you are going to get one month or even one year that is cooler or wetter than normal,” she said.
Andrus said changes to the 30-year average winter precipitation in town indicate Cortez is receiving about 0.63 inch less winter precipitation.
“It suggests our winters are slowly getting drier,” he said.
While winter’s may be drying out in Cortez, Andrus said he welcomes this season’s unusually heavy snowpack and wet May.
“We certainly can appreciate what it does for our local reservoirs, and we can even start refilling Lake Powell and Lake Mead,” he said.