Southwest Coloradans have reason to cheer: This year’s monsoon seems robust – a big change from last year when the summer rains failed to show up.
Jeff Colton, a meteorologist with the National Weather Service in Grand Junction, said last year’s failed season, when he estimated Southwest Colorado got only five days of rain from the monsoon, was a bit of an office joke.
“We called them the nonsoons,” he said. “Really, there was no monsoon last year whatsoever. But this year, moisture moved in, in late June. And it’s been kind of a pattern, where we get a week of wet weather, then a few dry days, and then the chance for rain returns.”
Rainfall in Southwest Colorado has been so plentiful that Stage 1 fire restrictions could be coming down in the next two weeks.
Durango Fire Protection District Chief Hal Doughty said the La Plata County Fire Chiefs Association will recommend dropping fire restrictions in conjunction with the U.S. Forest Service, a move that could occur later this week or next week.
Doughty said the procedure to declare fire restrictions in La Plata County has been streamlined since the county commissioners declared Stage 1 fire restrictions on June 16.
La Plata County Sheriff Sean Smith now is able to declare fire restrictions and also to drop them, rather than requiring a full vote of the county commission to set or lift restrictions.
Doughty said the La Plata County Fire Chiefs Association is seeking legal guidance to determine if the sheriff can drop the current restrictions or if the association needs to go before the county commissioners to end the current Stage 1 fire restrictions because they were initially enacted by the commissioners.
Whether the county commissioners or Smith drop Stage 1 fire restrictions, they likely will be lifted sometime in the next two weeks, Doughty said.
Andy Lyon, a spokesman with the San Juan National Forest, said the Forest Service discussed fire restrictions with regional fire agencies and other partners on Monday.
The discussion recognized that the fire danger has lessened in the last few weeks, but no firm date on lifting fire restrictions was determined.
“There was recognition that because of the moisture that we've gotten, that the fire danger has certainly lessened, especially in the high country, higher areas of the forest,” Lyon said. “But not everybody’s gotten moisture equally. We’re still getting lightning fires every day. Small ones, thankfully.”
The Durango Fire Interagency Dispatch Center reported 15 fires since Monday on tribal, federal and private property lands from Pagosa Springs to the Utah state line. All but one of the fires was contained to a tenth of a acre in size; one grew to a half-acre in size, Lyon said.
Lyon said a conference call with area fire chiefs came to a consensus on Monday that it was safe to lift the fire restrictions, but the consensus was not unanimous with fire officials in far western parts of the state and farther south, where they are concerned about how dry the areas remain.
As for a continuation of the monsoon, the forecast looks good.
Colton said: “Things are actually setting up now to where we’re looking at a 10- to 15-day period of afternoon showers and thunderstorms each day. That’s kind of like a more normal monsoon-type season where we’re seeing all this moisture moving up from the south.”
The monsoon is caused by a seasonal shift in wind patterns that allows moisture to come over the southwest United States from the Gulf of California and the Pacific Ocean, Colton said.
What allows the wind shift is a breakdown in the high-pressure system that usually sits over the Four Corners during the first half of summer.
“Eventually, we have a low-pressure system that develops over the southwest United States, and that changes our wind patterns from a westerly wind to a southerly wind, and those southerly winds will transport moisture off the Gulf of California and the Pacific Ocean,” Colton said.
The monsoon in the Southwest is typically defined from June 15 to Sept. 30.
But in Southwest Colorado, Colton said, the monsoon usually begins around the Fourth of July, with monsoon rains hitting Arizona and New Mexico earlier in the summer.
The Four Corners and Southwest Colorado are at the edge of the area of the Southwest hit by the monsoonal pattern.
Southwest Colorado’s rainfall received in late June was the official kickoff to this year’s monsoon, the earliest the season has started in Southwest Colorado in years, Colton said.
In a good year, the monsoon can linger in Southwest Colorado into mid-September.
Like the hurricane season, the monsoon has different intensities, like last year’s bust and the more bountiful rains coming this year.
Currently, it’s impossible for meteorologists to predict the strength of coming monsoons, Colton said.
“The science is growing,” he said. “We’re working on those types of predictors. Like El Niño and La Niña, sometimes we’re getting better at predicting the onset of those seasonal-type patterns. Eventually, we will reach the point where we’ll be able to hopefully predict the strength of the monsoon seasons better. We’re just not there yet.”
Steve Wolff, general manager of the Southwestern Water Conservation District, said in general the monsoon doesn’t have a big impact on the region’s reservoirs, which rely more on spring runoff from winter snowpack to replenish their levels.
If a good monsoon comes after both a particularly good runoff year and a good monsoon from the year before, monsoon rains have a chance of slightly notching up reservoir levels.
But that’s not the case this year.
Wolff said this year’s monsoon is coming after a year when regional snowpack ranged from 70% to 80% of average and last year’s monsoon was a nonevent.
The main importance of the monsoon, he said, is to put an end to the fire season.
Plentiful monsoons can help farmers to lessen the amount of irrigation water they draw from reservoirs, another beneficial aspect of the rains, Wolff said.
Most of the region’s irrigated farming comes in Montezuma County, drawing from McPhee Reservoir, west of Dolores.
Wolff said this year’s snowpack was so small and McPhee’s level was so low, most farmers dependent on McPhee decided not to plant crops this year.
That means this year’s rains are mostly falling largely on acreage held in fallow.
Additionally, the monsoon is a patchwork of rainfall events, and Wolff said this year’s monsoon has been stronger in La Plata County than in Montezuma County.
“Agriculturally, what monsoons can do, typically, is if you get good rains on crops, you don’t have to take so much out of storage,” Wolff said. “So it’s not like monsoons are going to put a lot of water in, but you may not have to use as much storage for irrigation.”
Except for Lake Nighthorse, reservoirs across Southwest Colorado are well below capacity.
Bob Wolff, president of the Animas-La Plata Water Conservancy District board of directors, said Lake Nighthorse is an anomaly among regional reservoirs because it does not yet have users drawing water from it. Currently, Lake Nighthorse is at 100% of its capacity, which is 115,075 acre feet.
Other regional reservoirs that do have end users are not nearly in as good a shape:
- McPhee Reservoir is at 171,669 acre-feet with a capacity of 381,100 acre-feet, or 45% of capacity.
- Jackson Gulch Reservoir is at 3,850 acre-feet with a capacity of 9,951 acre-feet, or 39% of capacity.
- Lemon Reservoir is at 10,328 acre-feet with a capacity of 39,792 acre-feet, or 26% of capacity.
- Vallecito Reservoir is at 68,899 acre-feet with a capacity of 125,400 acre-feet, or 55% of capacity.
- Navajo Reservoir is at 1,081,055 acre-feet with a capacity of 1,696,000 acre-feet, or 64% of capacity.