San Juan County's long-term moisture situation a mixed bag
NWS: Strong snowpack doesn't mean end of drought
- Over the past 17 months, San Juan County has received only 55 percent of its normal moisture.
- In the last 90 days, the Farmington area has received 180 percent of its normal precipitation.
- The snowpack in the San Miguel, Dolores, Animas and San Juan rivers watershed was 131 percent of median on Monday.
FARMINGTON — The abnormally dry conditions that have prevailed in the Four Corners region for the past year and a half, leaving most of San Juan County in a major drought, have shown signs of dissipating this winter.
But even with the snowpack in the southwest Colorado high country at an encouragingly high level, an official at the National Weather Service in Albuquerque is offering a mixed perspective on the region's long-term moisture situation.
"That's the big question," Royce Fontenot, the senior service hydrologist for the NWS office in Albuquerque, said today. "Do we balance the stronger short-term upswing (in moisture) versus the longer-term deficit?"
Fontenot said the NWS is nowhere near ready to declare an end to the drought.
"We're cautiously optimistic we're going to continue to see improvement, but we're still looking at the long-term drought and the damage it has done to the system."
Dry conditions settled in over San Juan County in early October 2017, Fontenot said, resulting in a devastatingly dry winter of 2017-2018 and a poor monsoon season last summer. Over the past 17 months, the county has received only 55 percent of its normal moisture, and that has left most of the county locked in varying stages of drought, according to the U.S. Drought Monitor.
The far west edge of the county is in a severe drought, the third-worst classification. Most of the rest of the county is in extreme drought, the second-worst classification. And an oval-shaped patch extending east from Farmington to the Rio Arriba County line is in an exceptional drought, the worst stage. That classification is typified by exceptional and widespread crop/pasture loss and shortages of water creating water emergencies.
But Fontenot said conditions have improved over the last 90 days. Over that period, the normal amount of precipitation the Farmington area would have expected to see was 1.65 inches. Instead, he said, it has gotten. 2.97 inches — 180 percent of normal.
"That really kicked off with the storm systems right after Christmas," he said.
Precipitation has continued to fall on a regular basis since then, and the next several days offer a fair chance for more, despite gradually increasing temperatures. According to the forecast posted on the NWS-Albuquerque website, a 40 percent chance of shows exists for Farmington on Wednesday, with a 40 percent chance of snow showers Friday night.
Even more moisture has fallen in the mountains of southwest Colorado, the watershed that feeds San Juan County's rivers. According to the U.S. Department of Agriculture's Colorado SNOTEL website, the snowpack in the San Miguel, Dolores, Animas and San Juan rivers watershed was 131 percent of median today, the wettest region in all of Colorado.
That's good news for San Juan County, but Fontenot urged local residents not to get too excited about those numbers.
"I was just up in the Farmington-Aztec area last week," he said. "I think there are a lot of people looking around the southwest Colorado mountains, and they see a lot of white. You see that improvement."
But, in this case, your eyes can deceive you, he said. It's best not to count on all that snow reaching a river until it actually gets there.
"Snowpack does disappear," he said. "You lose some of that moisture before it melts."
Windy conditions can disperse much of that snow, and it can simply evaporate, Fontenot said. And if it turns warm too quickly this spring, the snowpack can all melt at once, sending much of that moisture downstream before it can be used.
Another factor working against the region, he said, is the soil moisture content. The period from October 2017 to December 2018 was so dry, he said, that much of the snow that has fallen from the sky won't wind up in a river as it normally would.
"As the snow in the San Juans starts to melt, we've got to replenish the soil moisture," he said. "That's a big factor going into this spring, as well."
The good news is that the 90-day forecast shows San Juan County sitting on the boundary between normal precipitation and above-normal precipitation, although that is balanced by a forecast showing normal to above-normal temperatures.
"The trend is for a normal to wetter-than-normal pattern," he said, adding that the Four Corners would be better served by a winter and early spring that sees several smaller storms rather than a large one. "You don't want a big dump of rainfall and snowfall in one big event. If it comes fast, it goes fast. You want a slow melt with normal runoff."
This year's wetter-than-normal winter is only the first step in getting San Juan County back to normal, he said.
"You're going to need a good winter, which we're having so far, along with a good spring and a good monsoon season," he said. "It's a big hole that was dug, and it's going to take a long time to get out of it."
Mike Easterling can be reached at 505-564-4610.