Monsoon comes early to New Mexico, but 3rd straight La Niña looms
FARMINGTON — While the Southwest in general and the Four Corners in particular may be off to what looks like a record-setting start to the monsoon season, the long-term moisture outlook is increasingly grim.
A series of monsoon storms blew through the state over the past several days, bringing milder temperatures and rainfall to the parched landscape. Andrew Church, a meteorologist for the National Weather Service in Albuquerque, said that appears to be the earliest start ever registered for the season summer storm pattern – and more precipitation is likely on the way over the next several days.
"Over the weekend, we could see more rainfall," he said, noting that some of those storms could produce locally heavy moisture in San Juan County. "It is definitely possible."
Church, who produces the agency's annual monsoon outlook, said some of the data that came in early this summer gave an indication that the monsoon could set up quickly. In that respect, he said, the early start to the season wasn't exactly a surprise, although the 20-year megadrought that has plagued much of the West has taught many sky watchers to keep their hopes in check.
But every so often, he said, the high pressure dome that has set up over the Four Corners in the summer for the last two decades and that steers southern moisture away is late in arriving. That's what is happening this year, Church said, meaning the chances of monsoon moisture falling in the Four Corners are good for the rest of June and early July.
After that, the long-term climate models are showing a return to a drier pattern, Church said, which is what happened last year when monsoon activity was robust for much of the state in June and early July before tapering off, especially in August and September.
This year's monsoon forecast that was released on June 5 shows that the western half of New Mexico stands an equal chance of receiving above-average or below-average precipitation, while the eastern half of the state leans toward below-average precipitation.
That part of New Mexico already is in the worst position drought wise, with most of the eastern one-third of the state classified as being in exceptional drought, the worst category. A large swath of the western half of the state also is in exceptional drought.
But San Juan County has dodged the worst of drought, for now. Most of the county is in extreme drought, the second-worst category, while smaller portions are in severe or moderate drought.
At the Four Corners Regional Airport, only 1.4 inches of precipitation had fallen through June 23, according to data supplied by Church, with the wettest month of 2022 being March, when 0.69 inches of moisture fell on the city. The average total through the end of June for the last 30 years is 3.13 inches, so unless this weekend's storms yield a bounty of moisture, Farmington will finish the month well below its historical norm.
The monsoon forecast also shows that most of the northern half of New Mexico likely is in for above-average temperatures this summer, with the southern half of the state leaning in that direction.
The outlook gets even worse late in the year and beyond. New Mexico's precipitation chances have been hampered the past two years because of the development of back-to-back La Niña phenomena in the Pacific Ocean, a condition that typically results in reduced moisture for the American Southwest in the winter and early spring.
Such "double dip" La Niñas are not the norm, but they have become increasingly common over the last 20 years, deepening the drought throughout the West that the monsoon forecast calls the region's most severe in at least 1,200 years.
Now, Church is worries that conditions are poised to get even worse. He said there are strong indications that a third consecutive La Nina will take place this winter.
"It has happened twice since 1950, so it's very rare," he said. "And if we extrapolate back from the data, it looks like it's happened four times since 1900. But it's looking more likely with each month. … It looks like we're in for a triple dip."
Church said every La Niña is different, but if another one does set up this winter and follows recent patterns, it will affect springtime precipitation the most. He said the amount of precipitation that falls during winter can be close to normal even in a La Niña year, but the totals for March, April and May are often greatly reduced.
He anticipates seeing those same conditions again in the spring of 2023.
"What we saw this spring is probably going to be (repeated)," he said. "It all depends on when the La Niña begins to fade."
Mike Easterling can be reached at 505-564-4610 or firstname.lastname@example.org. Support local journalism with a digital subscription: http://bit.ly/2I6TU0e.