Nobody lives for weather in Cortez like Jim Andrus.
As an observer and spotter for the National Weather Service, he has been recording daily weather data and watching out for storms and phenomena for the past 25 years.
In May, the retired meteorologist received a Length of Service award from the National Weather Service for his dedicated volunteer efforts that started in 1997.
“I’ve come to think of a weather observer as checking the pulse of the Earth,” he said. “Right now, we are running a fever with a 22-year megadrought.”
After getting his meteorology degree in 1968, Andrus did weather work for the Air Force from 1968 to 1972. He worked for the National Oceanic and Atmospheric Administration from 1973 to 1976 and was a weather service programmer in Washington D.C. from 1976 to 1979. He worked for the weather service in Juneau and Anchorage, Alaska, before retiring in 1994.
Every morning of the year at 8 a.m., he goes to a weather station around the corner from his Cortez apartment and records the daily high and low temperatures, rainfall and snowfall of the preceding 24 hours.
The information along with observations are called into the National Weather Service station at Grand Junction for use in daily reports and forecasts.
He regularly presents weather data, trends and forecasts to the local government boards and keeps local news media informed.
“As a weather spotter, I also report unusual weather like tornadoes, funnel clouds or extreme wind. During storms with heavy rain, hail or snow. I’ll take hourly measurements that help forecasters determine the intensity of the storm,” Andrus said.
Some events stand out.
A funnel cloud was recorded in 2019 east of Cortez, and three were sighted near Cahone in 2015, which led the weather service to issue a significant weather advisory.
In 2011, was a “bodacious winter with over 6 feet of total snowfall, double the average,” he said.
An apparent weather trend in Cortez is decreased precipitation and increased temperatures based on updated 30-year averages, Andrus said.
Current annual average precipitation for Cortez is 11.79 inches, down from 13.2 inches in 1997 when Andrus started as an observer.
“I have some doubt on the future of the Southwest, and wonder if it is slowly dying as the megadrought continues,” he said.
One thing about Cortez weather he has noticed is that the city tends to be in a small precipitation shadow created by the Mesa Verde geologic formation when storms come in from the south.
As storm winds descend the mesa on the north, they warm up and create increased evaporation of the precipitation, like a miniature chinook wind, he said.
“Precipitation forecasts can be less for Cortez because of the snow shadow,” he said.
Andrus said a new weather radar station planned in La Plata County should improve National Weather Service forecasts for the region.
Four Corners residents live in a radar blind spot that hides low-altitude storms because the curvature of the Earth limits straight-line detection by faraway radar stations in Grand Junction, Flagstaff and Albuquerque.
For example, the Grand Junction radar station lowest reach for Cortez is an altitude of 23,000 feet, but the tops of winter storms can be well below that.
In summer 2014, Andrus alerted the service to a severe storm that approached Cortez from a blind spot near Ute Mountain. The storm had the potential for hail and high winds, and the weather service issued a warning based on Andrus’ report from the ground.
“A local car show scrambled to protect their cars,” he said. “Radar can miss lower-level storm events. Weather observers provide ground truthing. I love the science of it.”
Andrus never misses a chance to provide a weather update.
Year-to-date precipitation through the end of May is 2.2 inches, or 49% of the average.
Cortez had two high daily temperature records this month.
On June 11, the Mercury hit 95 degrees, beating the 2016 record of 92 degrees. On June 12, it was 95 degrees again, beating the 2013 record of 92 degrees.
An early monsoon season began in June, dropping 0.31 inches in Cortez, or 83% of average precipitation for the month.
“This is the best start for monsoons in three years, its promising,” Andrus said. “The weather pattern is perfect to draw moisture up from the eastern Pacific and Gulf of Mexico.”
The forecast for Thursday and Friday show a 40% and 30% chance of showers and thunderstorms, respectively.