What the snowy winter gives, the heat takes away: #Aridification Watch returns — @Land_Desk

A retardant drop on the York Fire in the Mojave Desert. National Park Service photo.

Click the link to read the article on The Land Desk website (Jonathan P. Thompson):

Aridification Watch

Now that July is over, the official meteorological diagnosis of the month is in: It was friggin’ hot! On a global level, it was the hottest month on record, maybe even the hottest in the last 120,000 years. The figures for the West aren’t in yet, but I think we can all agree it was an abnormally warm and dry month for most places.

Phoenix experienced a full month — i.e. 31 consecutive days — of 110+ degrees Fahrenheit maximums (from June 30 to July 30; the streak was broken July 31, when the mercury topped out at a chilly 108 F). That included three 119-degree F days and a record-breaking overnight low of 97 F. And the average daily temperature for the month was nearly 103 degrees, shattering the old record and more than seven degrees above “normal.”

Although the monsoon has made it to some parts of southern Arizona, dumping three-fourths of an inch of rain on Tucson and knocking out power to some 50,000 people, it’s missing other parts of the state. Phoenix-proper hasn’t received measurable precipitation since March 22. Ugh.

Sure, that’s Phoenix, which is always a cauldron. But how about these all-time record-breakers?:

  • 120 degrees F: Maximum temperature in Ajo, Arizona, on July 20, breaking the previous record of 119 F set in 2021.
  • 93 F: Maximum temperature in Del Norte, Colorado — at nearly 7,900 feet above sea level — on July 26 and 27, breaking the record set in 2015.
  • 85 F: Maximum temperature at Parker Peak, Wyoming — at 9,400 feet in elevation — on July 24, breaking the record set a day earlier (previous record: 82 F set in 2002).
  • 78 F: Minimum temperature at Bredette, Montana, on July 23.

The point being it’s hot everywhere, even in the high country, and always, even in the coolest part of the night in Montana.

The good news is that all that heat was preceded by a really wet winter and spring, saving us from complete disaster. The bad news is the heat has conspired with a late-arriving monsoon to suck up a lot of that moisture, leaving less for the rivers and vegetation tinder-dry and flammable.

Here’s a look at precipitation at the Columbus Basin SNOTEL site in the La Plata Mountains of southwestern Colorado. There were big snows from late December into March, then someone turned off the taps it seems and the usual mountain rains didn’t materialize in early July, per normal. Now it’s just started raining. Let’s hope it keeps up.

The big winter resulted in a big spring runoff, naturally. But the high heat + low spring-summer precipitation melted and evaporated the snow, dashing hopes of an extra-long rafting season on many streams. After running far above median levels even into late July, many rivers — including the Dolores and Animas — are now running below normal for this time of year. That ripples downstream to Lake Powell, where inflows have also dropped rapidly since July 1, and are now even below 2022 levels for this date, causing reservoir surface levels to drop four feet in less than a month. A good, Colorado Plateau-wide monsoon will help fix that — if it materializes — but continued heat will continue to sap moisture from the streams and reservoirs.

This all meshes with a new study on climate change’s effects on the Colorado River. The researchers nicely summarize the key points of the study:

We find that the basin has roughly 10% less water available under present-day conditions due to warming since the 1880s. The majority of water loss has occurred due to a heightened sensitivity to warming in the basin’s regions associated with snowpack, compared to regions without snowpack. We also demonstrate that without this warming, the Colorado Basin would have had significantly larger amounts of water available, equal to the size of Lake Mead, over the duration of the 2000–2021 megadrought.

Did you get that? Climate change has stolen a whole Lake Mead from the Colorado River over the last couple of decades and the hydro-thievery will continue and even accelerate as temperatures rise.

This should provide yet more impetus to efforts to stop burning fossil fuels in the hope of slowing warming. But it also should be a reminder that even if drought conditions have subsided, the big aridification has not ended. We can’t be lulled into complacency by a good snow year, even a record-breaking one, or some flash-flood-triggering downpours. Lake Powell is still less than 40% full. The Colorado River still carries less water than has been allocated to its users, meaning they collectively must cut consumption by at least 2 million acre-feet per year, likely a lot more. Easing water use restrictions is a bad idea. The heat is in it for the long haul, I’m afraid, and we must act accordingly.

Fire season got a pretty slow start across most of the West, but now it’s upon us and it’s getting ugly in some places, with new blazes in Arizona, Montana, Alaska and Washington. The Hayden Fire in Idaho has burned through 18,000 acres.

Perhaps the most severe blaze is the one that may have seemed the most unlikely: The York Fire, which has torn through 77,000 acres of Joshua Trees, junipers, cacti, and other Mojave Desert vegetation along the California-Nevada border southwest of Las Vegas. It has bled into the newly established Avi Kwa Ame National Monument and is moving toward the Wee Thump Joshua Tree Wilderness. The fire’s severity has been exacerbated by a buildup of fuel — including invasive grasses and mustards — resulting from the wet winter and spring.

Chris Clarke, in his Letters From the Desert newsletter, has a short yet powerful, heartfelt early impression of the fire. I’d suggest you read it and then subscribe to his newsletter, a lovely chronicle of the Mojave Desert.

Random Real Estate Room

Christian Burney has a nice piece in today’s Durango Herald about how “Bicycle Bob” Gregorio — an all-around good guy, genius bicycle mechanic, and longtime fixture of the Durango cycling community — is building an adobe home in Aztec, New Mexico. The project is cool; the thing compelling him to do it in Aztec, not so much. Gregorio was priced out of the Durango housing market after living there for decades. It just seems wrong that one of the town’s icons can’t live in the place he loves and to which he as contributed so much.