The culprit behind this year’s abnormally warm temperatures and lack of snowfall in Southwest Colorado – a weather pattern known as La Niña – is showing no signs of breaking down.
“It’s unfortunate,” said Chris Cuoco, a meteorologist with the National Weather Service in Grand Junction. “This is turning out to be one of the driest starts of the year in a very long time.”
One of the major dictators of weather in Southwest Colorado turns out to be surface water temperatures in the eastern-central Pacific Ocean that come in cycles known as the “El Niño-Southern Oscillation climate pattern.”
When surface water temperatures are warmer than normal, that kicks of an El Niño year, which can bring wetter-than-average conditions to the Southwestern U.S., depending on the strength of the El Niño, as well as other factors.
Yet El Niño’s seemingly evil counterpart – La Niña – occurs when surface water temperatures in the Pacific Ocean are colder than normal by about 3 to 5 degrees, Cuoco said.
During this period of La Niña, which can last up to five months, little, if any, precipitation makes it to Southwest Colorado as storms are pushed up to the northern parts of the state.
And this year, Cuoco said it’s playing out like a classic La Niña year.
As of Sunday, Southwest Colorado’s snowpack is at 34 percent of normal averages, while the Colorado, North and South Platte, and Yampa river basins are experiencing upwards of 75 percent of normal snowpack.
According to NWS data, only 0.39 inches of precipitation were recorded at the Durango La Plata County Airport for the entire month of January, about 1.12 inches below historic averages.
Last year, which was an El Niño year, more than 2.35 inches of precipitation was recorded for the month of January at the Durango-La Plata County Airport weather station.
Also, this past January was nearly 5.5 degrees warmer than historic averages.
The U.S. Drought Monitor lists nearly all of Western Colorado and the Four Corners region in a “severe drought.”
And unfortunately, NWS models show no signs of La Niña going anywhere anytime soon.
While scientists are able to track and measure global oceanic circulations, and know how these cycles move, they are less certain about the driving forces behind it, Cuoco said.
“What causes surface water temperatures in the ocean to warm back up toward normal, or to cool down?” Cuoco said, “we really don’t have that answer yet.”
Cuoco said the World Meteorological Organization, an intergovernmental organization comprised of 191 countries and territories, has been funding research to get at the answer for years.
These oscillations in surface water temperature have resounding impacts on weather conditions around the globe.
In El Niño years, for instance, parts of Southern Africa, the Philippines, Mexico and Central America may experience extreme drought, while areas like Bolivia, Ecuador and Cuba may get hit with catastrophic flooding.
Therefore, understanding what causes a particular year to have warm or cold surface water temperatures is a question sought after by the international community, Cuoco said.
“It’s something that has been well funded with widespread research in the hopes of understanding,” he said.
As for Southwest Colorado and its parched landscape, any hint of snow comes as a bit of good news.
Cuoco said there’s a slight chance the high country north of Durango – areas around Silverton, Hesperus, Rico and Ouray – have a 30 to 40 percent chance of scattered snow showers Monday through Tuesday.
If the storms pan out, it may drop a couple of inches, Cuoco said.
“There’s only a slight chance, but it’s the best we’ve had in a while,” he said.
jromeo@durangoherald.com
