June rains have showered Southwest Colorado in the last week, surpassing monthly precipitation normals and improving fire and rafting conditions.
Forecasts predict the moisture will continue, signaling the potential for an early start to the monsoon and bringing more relief after a dry May. Yet, fire and weather officials and scientists warn that a strong start to the summer will not end long-term drought or eliminate fire danger.
“The fact that this very monsoon-like weather pattern has already started and it’s still June, I do think that’s a really good sign of at least not making the drought worse and mitigating the impact(s) of the drought,” said Jonathan Harvey, a professor and chairman of the Geosciences Department at Fort Lewis College.
June is Southwest Colorado’s driest month, but rain over the weekend and into the week has been above normal for much of the Four Corners.
Over the weekend, 1.2 inches of rain fell in Pagosa Springs, surpassing the roughly 0.75 inches of precipitation the area normally receives in June, according to climate normals from the National Centers for Environmental Information.
In Durango, 1.16 inches of rain saturated the ground as of Monday, more than doubling the city’s usual June precipitation.
Silverton, too, saw 1.67 inches of rain over the weekend, exceeding its monthly normals by about 0.75 inches.
Cortez is nearing its 0.37-inch average with 0.31 inches of precipitation so far in June, according to the Centers for Environmental Information and National Weather Service data.
The benefits have been immediate.
“It was enough to impact the short-term hydrologic cycles in terms of shutting down the fire hazards considerably and helping with soil moisture,” Harvey said. “There were heavy enough rains that they actually did sink into the soil, especially in the places that were under the bigger cells.”
For half of La Plata and Archuleta counties and all of San Juan County, the U.S. Drought Monitor downgraded drought from extreme to severe on Thursday.
The Animas, San Juan and Dolores rivers rebounded over the weekend, with the Animas River swelling from a low of about 600 cubic feet per second to a peak of 1,470 cfs on Monday.
“The river was just at a really fun level from the rains and remains at a really fun level,” said Alex Mickel, co-owner and president of Mild to Wild Rafting and Jeep Tours. “We’re getting more into the summer tourism season so business is picking up, so we’re happy to have improved water conditions for folks.”
On Wednesday, the Southern Ute Indian Tribe rescinded Stage 2 fire restrictions and transitioned back to Stage 1 precautions.
San Juan National Forest and La Plata County announced Thursday that they will be moving back to Stage 1 fire restrictions Friday.
The rain has moderated fire danger, said Lorena Williams, spokeswoman for San Juan National Forest.
“This early onset monsoon was terrific and made June a much more favorable outlook as far as fire is concerned,” she said.
After heightened fire danger in Southwest Colorado in June, the National Interagency Fire Center projects normal fire potential through the summer.
A high-pressure system in the Southern Plains of Texas and Oklahoma has been causing the rain. The system has been funneling moisture from the tropics into the Four Corners, said Brianna Bealo, a meteorologist with the National Weather Service in Grand Junction.
While it’s too early to say if the moisture is a start to Southwest Colorado’s monsoon, which typically begins around the second week of July, Bealo said there is some evidence to suggest that June’s rains signal their arrival.
“We do have some local research here at the Grand Junction office that indicates that toward the end of a La Niña cycle, which is where we’re at right now, we do tend to see an earlier onset of the monsoon,” she said.
National Weather Service forecasts project more rain this weekend and throughout next week.
“You’re going to see chances of showers and thunderstorms pretty much every afternoon going forward at least through the next several days,” Bealo said. “With this consistent moisture overhead (from the high-pressure system), I would suspect you’d see something closer to smaller amounts of precipitation more consistently just because there’s a more consistent moisture source to work with.”
More so than volume, the regularity of the rains over the last week has perhaps had the greatest benefit.
In Southwest Colorado, heavy rains followed by periods of heat and dryness do little to mitigate drought, boost streamflows or reduce fire danger. Dry weather intensifies evapotranspiration, which can deplete recent rains and parch the land.
Prolonged precipitation seeps further into the soil, which then acts like a reservoir supporting rivers and extending water resources later in the year. Cloud cover from storms also reduces the sun’s energy that reaches the ground and drives evapotranspiration.
“If you can really sustain (rain) for many days or many weeks like some epic monsoon years in the past, you are more able to saturate deeper into the soil and into the subsoil (and) deeper groundwater systems that are very hard to recharge otherwise,” Harvey said.
But while June rains have been a boon for Southwest Colorado, Harvey and the others urged caution.
Even with the moisture, Montezuma and Dolores counties remain in extreme drought, and the rain does little to ameliorate the long-term drought that’s been gripping the Four Corners.
“It’s a lot easier to take the water out of the ground than it is to get it back in there,” Harvey said. “It does take multiple seasons where you have that sustained daily rainfall to really get it deeper into the groundwater.”
Snowpack has more of an effect on drought than rain, Bealo said.
Just as the rains have appeared in a week, they could quickly disappear. The high-pressure system in the Southern Plains that is keeping moisture in Southwest Colorado could move and take the rain with it.
“If anything about that overall pattern shifts, then that can cut off or shunt the moisture away from us,” Bealo said. “It’s one of those things where we have to take it day by day, week by week.”
With many fuels already dry from an arid spring, the heightened fire danger of late May and early June could easily return without more rain.
“All it takes is a long drying period and we could be right back to where we started,” Williams said. “What we need to see is monsoons continuing.”
While it’s too early to forecast, June’s rains have spurred hope for a summer of thunderstorms.
“I’m very optimistic about what all the signs are pointing to for the next few weeks, and it really does feel like an early start to what will hopefully be a robust monsoon season taking us into August,” Harvey said.
ahannon@durangoherald.com
