Warmer, drier trend continues

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Winter forecast > Mild La Niña expected to give way to neutral conditions

By Arin McKenna

On Friday, a winter snowstorm that promised to bring significant moisture once again came in with a whimper. Instead of the promised four to six inches of snow (early forecasts predicted as much as six to eight inches) Los Alamos received only 2.1 inches.
That is not the first time that initially promising storm patterns left Los Alamos high and dry. According to both Chuck Jones, senior meteorologist for the National Weather Service/Albuquerque and Los Alamos National Laboratory Meteorologist David Bruggeman, reduced precipitation and warmer temperatures are not only the trend for this winter but a long term trend dating back decades.
According to Bruggeman, Los Alamos has seen a downward trend in annual average precipitation since 1981. Snowfall has been declining since 1951.
Both Bruggeman and Jones are predicting this winter will continue to be drier and warmer than usual. Charts from the National Oceanic and Atmospheric Administration’s Climate Prediction Center (cpc.noaa.gov) show all of New Mexico with a 50- to 60-percent chance of having above normal temperatures for the next three months and a 33- to 40-percent chance of below normal precipitation.
New Mexico is currently being impacted by a mild La Niña, caused by below-average sea surface temperatures across the east-central Equatorial Pacific. New Mexico tends to have less precipitation in La Niña years.
“We’ve mainly had the storm systems moving by to our north, so all we end up with across northern New Mexico is some wind and maybe a brief cool down,” Jones said.
“It typically does not last an entire winter…So overall, we’ll continue with a reasonably dry and warmer than normal winter, but there’s hope that that pattern can change latter this month or in February and we can still get some snow.”
According to Bruggeman, the La Niña is predicted to change to neutral conditions sometime between January and March, but both patterns trend toward lower than average winter precipitation for Los Alamos.
That continues an overall trend from 2016. NOAA just announced that 2016 was the second warmest year on record in its 122 years of record keeping. According to Jones, 2016 was the third warmest year for New Mexico, dating back to the late 1800s. LANL’s records show that 2016 was the second warmest year for Los Alamos since 1954, just below 2012 temperatures.
“We actually have weather data going back to 1910 here. There were some farmers, before the lab came here, that recorded the amount of precipitation that fell and even maximum and minimum temperatures,” Bruggeman said.
Bruggeman allows that the homesteader recorders were spotty, with gaps in the data, “because they took Sundays or weekends off, and then, when the work came, they didn’t take any records during that time either.” But the record shows a definite increase in temperature since that time.
According to Bruggeman, more recent data shows a definite trend toward warming temperatures. Comparing 30-year averages between 1951‒1980 and 1981‒2010 shows a temperature increase of one degree.
“So we have seen a little bit of a warming trend just from the data we have,” Bruggeman said. “It certainly seems like things are going to keep continuing down this path where drought will get worse.
One degree may not sound like a lot, but New Mexico is definitely feeling the impact of that one degree change.
“A lot of the impact comes from water. As the climate warms, we’re supposed to be getting less precipitation,” Bruggeman said. “We can also get stronger rain events. So stronger storm events like in Sept. 2013, where we had such a heavy flood. (According to a LANL report to the Department of Energy and Environmental Services, Los Alamos received between 200 and 600 percent of normal precipitation between Sept. 10‒17 that year)
“As climate change progresses, we would expect more of those to happen, more of those strong events. But overall, more of a decrease in precipitation, so we’d have less water and more drought.”
According to Jones, one of the greatest areas of impact for that trend is on spring runoff.
“Unfortunately, for the last six springs, the snowmelt has started a month or more early and ended a month or more early, and the runoff has been well below what it normally is,” Jones said. “So if we stay status quo like we are now, it’s liable to be a below normal runoff.”
Jones noted that both the San Juan and the northern Sangre de Cristo Mountains near the Colorado border actually have near normal and above average snowpack, but that will do nothing to help Los Alamos.
“It diminishes pretty quickly as you head south,” Jones said.
According to Jones, the number of El Niño (which brings New Mexico above average winter precipitation) and La Niña events are not increasing, but both events have been growing stronger and having more impact over the last decade or two.
“So if we get into a La Niña pattern, it tends to make things even drier and warmer than what we would expect in previous La Niña years,” Jones said.
Compared to some recent years, there is some good news for skiers. Pajarito Mountain Ski Area reported nine inches of new snow from Friday’s storm, and 42 inches year-to-date with a base depth of 33 inches. Thirty-two of its 44 trails are open. Find more information at skipajarito.com.
For more information about both short term and long-term weather patterns, visit the National Weather Service/Albuquerque site at weather.gov/abq or LANL’s “The Weather Lab” at environweb.lanl.gov/weathermachine.