From Jim. Not computer related but important to all of us.
Although I do enjoy living in Arizona, there are two issues that are of continuing concern to me and those living in southern Arizona -- a sustained drought, and very high heat. The following article from our local paper has a discussion on our drought, should you have an interest in reading it. It is a bit lengthy, but will be of interest, I think, especially for those of us living in southern Arizona.....Jim
Arizona drought persists: 'You can't get much lower than this,' experts say about water levels. The current short-term drought is as bad or worse than droughts in 2017 and 2020, according to a UA researcher, stretching across summer, fall and winter. Tree ring research shows prolonged dry periods are normal in Arizona, but the current drought, in its third decade, is one of the worst in 1,200 years or more.
The lack of snowpack could raise risks of wildfire in the high country, bringing an early start to peak fire activity. An active monsoon could ease the threat. When hydrographic scientist Luis Hernandez wades into the Salt River in a typical February, he has to watch his footing as the water rushes by.
Runoff from winter precipitation resulting in heavy streamflows can make his job difficult, even dangerous, as he dons his waders to guide Salt River Project’s remote-controlled boat into the water.
Although the green and blue boat may be small, it plays an important role in SRP’s operations. It measures the velocity of river water and, ultimately, its inflow into Roosevelt Lake, one of the primary reservoirs SRP uses to store water for over 2 million people in Phoenix.
But after months of short-term drought across Arizona, the stream gently rippled by on a February outing. The water level was so low it didn’t reach the rocky riverbank. It was a sign of how the lack of precipitation during the 2024 monsoon and the following abnormally dry fall and winter seasons could create problems in the months ahead.
“For a lot of winter, there’s been no snow in areas we’re usually flying over and measuring the snowpack,” said Bo Svoma, principal climate scientist and meteorologist for SRP. “We haven’t done one (snow survey) this year.”
The Salt and Verde Watersheds aren’t the only places unusually dry over the last few months. Arizona and much of the Southwest have been in a short-term drought, one of the worst in recent history. “In terms of short-term drought, it’s comparable to 2002, 2018, 2021,” Svoma said. “You can’t get much lower than this.”
Phoenix endured its second-longest dry spell on record, with 159 days without measurable rainfall from the end of a lackluster 2024 monsoon through January 2025. In Flagstaff, Arizona’s snowiest city, snow on the peaks during most of the season was created by Snowbowl snow machines.
While a few early March storm systems brought snow and rain across much of the state, it won’t be enough to offset months of extreme drought. “It’s going to do very little to move the drought indices in both the short and long term,” said Michael Crimmins, a climatologist at the University of Arizona. “We have precipitation deficits that extend all the way back to the summer. It’s just too late in the season.”
But how bad is the drought in Arizona, especially compared to infamous droughts in the state’s history?
While tree ring records show dry years are normal across the arid Southwest, climate change could be worsening the effects of modern-day droughts. With each day further into spring, the chances for major storms and significant snowmelt decrease while wildfire risk grows.
What the current short-term drought looks like. This short-term drought is just as bad, if not worse, than notable droughts in Arizona’s past. Crimmins believes this event is a “mash-up” of the 2017-2018 and 2020-2021 droughts.
The 2020 monsoon season was poor, triggering a significant short-term drought, but the state received scattered precipitation through the winter in 2021. The fall and winter seasons in 2017 and 2018 were particularly dry and warm as well.
This year’s drought is a combination of all three conditions — abnormally dry and warm summer, fall and winter seasons — making it one of the worst short-term droughts on record.
Last summer was the hottest on record in Arizona, and the monsoon produced fewer storms overall than in previous years. Sky Harbor Airport recorded just 0.74 of an inch of rain the whole season, the seventh-driest monsoon on record.
Scorching temperatures and new heat records continued through the fall. The winter storm track primarily clung to the Colorado-Utah border, staying about 100 miles north of Arizona and keeping the state remarkably dry.
Even though spring storms have hit the state, it won’t be enough to end the drought or significantly increase precipitation totals. “Unless something extraordinarily epic happens, we’re not going to come anywhere close to average,” Crimmins said. “Two of our wet seasons, summer and winter, being dry in a row puts us in a bad spot, and that’s what we’re dealing with right now.”
The La Niña cycle brewing over the last year played a role in keeping things dry. La Niña is a climatological event stemming from warmer-than-normal sea surface temperatures in the western Pacific Ocean. These events influence weather around the world, typically bringing warmer and drier conditions to the Southwest.
Persistent dry spell: What will it take to end 3 decades of drought in Arizona? Tree rings show drought is normal.
While this drought is particularly strong, prolonged dry periods are normal in Arizona, dating back hundreds of years according to tree ring records.
“The tree ring record shows lots of years that have severe droughts,” said David Meko, emeritus research professor at the University of Arizona’s Laboratory of Tree-Ring Research. “This is a stressful year for sure in terms of drought, but it’s not unheard of.”
To track annual rainfall, dendrologists — scientists who study trees — examine the width of a tree's annual growth rings. If a tree is under stress from low precipitation and high temperatures, which increases evaporation, its growth ring for that year will be narrow.
Dendrologists can create tree chronologies dating back centuries, sharing insights into an area’s climate beyond the instrumental record. Meteorologists only began recording weather data in Arizona in the late 1800s.
“The tree ring record gives an extended view of climate variability,” Meko said. “When we rely on just the streamflow record, it’s like a snapshot of variation.” When using the instrumental record to observe wet or dry years, scientists only have a window of about 100 years to look at. But tree rings give a wider window, which can go back a thousand years.
“You need this extended record to get a good picture of what the natural variability could be,” Meko said.
Tree rings show Arizona and the greater Southwest have wide variability, ranging from extremely dry years with short and long-term droughts, to wet years that offset them.
The current long-term drought, which has been ongoing in the Southwest since 1994, is one of the worst, even in the tree ring record. “It’s right in the ballpark with the worst droughts of the last 1,200 years by our best record,” Meko said. “It’s a really unusual, extended drought.”
Tree rings prove short- and long-term drought are a natural part of life in the arid Southwest. But the symptoms of drought are worsening due to global warming. “If you have the same drought deficit as maybe 500 years ago and it happens now, it’s more stressful on the environment because the temperature puts an added stress,” Meko said. “As it gets hotter and hotter, these droughts are going to have a bigger and bigger impact on the environment, trees and water supply.”
Rising temperatures due to climate change can worsen the effects of dry spells. With a dry monsoon that’s excessively hot, the heat dries out the soils and worsens drought effects. This can happen during a warm, dry winter as well.
Above-normal winter temperatures can result in less snow than usual, and any snow that lands on parched soils will melt back into the ground rather than run off into local water supplies.
“Climate change is messing with the water balance across the Southwest, even if the precipitation variability is as wonky as it’s always been,” Crimmins said. “We’re built for this kind of crazy climate, but adding the temperatures on top of it is the real problem.”
How snowmelt — or the lack of it — affects wildfires. Arizona’s peak snowpack occurs around March 1, but unexpected snowstorms could hit the high country well into spring. “The pattern could turn wet for a couple of weeks, but that would do very little to help with the situation in the Southwest,” Crimmins said.
As of March 26, Flagstaff Airport accumulated 46.8 inches of snow since July 1. The average snowfall to that point is 82.1 inches. Of this season’s total, 35.6 inches fell in March. Meteorologists say that while this is a slight improvement, the snowpack is still well below normal.
Spring precipitation won’t be enough to boost this year’s snowpack to average totals or trigger significant runoff.
After months without substantial rain or snowfall, soils across Arizona’s watersheds are extremely dry. The parched soil acts as a sponge during precipitation, restoring water levels in the ground.
Most snow accumulated in the high country will likely melt into the soil this year rather than run off into the water supply. “We still have above-average storage in our reservoirs because of previous wet winters,” Svoma said. “It would be just one wet winter to recover from this.”
SRP’s reservoirs filled to near capacity after wet winters in 2023 and 2024. As of Feb. 17, SRP’s reservoirs were still 71% full, even after months without significant precipitation. SRP plans for dry years, determining how much of its water supply will come from surface water in reservoirs and how much groundwater to pump around metro Phoenix. During wet winters, water managers favor surface water to preserve groundwater and rely more on groundwater pumping during dry years.
While Arizona’s short-term water supply is guaranteed, this year’s peak fire season could be severe. “Wildfires really start to pick up in March and then April, May and June are prime time,” Crimmins said. “The thing about this year is that with no snowpack, fires could start early. It could be ongoing in March.”
With extremely dry conditions across the forests and rangelands, wildfires could spark and spread easier than usual.
Recent precipitation could delay fires, but will only by a few weeks according to Crimmins.
Because these are late-season storms, the sun's angle is higher, melting the snow quicker. Any moisture likely will be absorbed into surface-level soils rather than penetrating deep into the ground.
Higher spring temperatures and stronger sunlight will spur evaporation, and as plants come out of dormancy, they will likely retain any remaining moisture. One snowstorm won’t keep the environment damp enough to sustain through the rest of the spring and prevent fires.
While the high country will be at extreme fire risk over the next few months, the lower deserts may fare better during peak fire risk. Without significant rain, perennial grasses that act as kindling in the desert likely won’t grow back as densely this year.
For now, one of the worst short-term droughts on record will persist in Arizona as spring tends to bring drier weather. But all it could take is an active monsoon to ease or even end the short-term drought.
“I’ll be really excited to see how the monsoon might come online. We won’t know until we’re almost on top of it,” Crimmins said. “I think there’ll be such anticipation for that first monsoon precipitation event because I think we’re going to be in a long, dry stretch here.”