Click the link to read the briefing on the Western Water Assessment website:

October 5, 2022 – CO, UT, WY

Precipitation during September was near-to-above average in Utah and Wyoming, but below average in much of Colorado. September temperatures were the hottest on record in much of Utah, western Colorado and western Wyoming. Consistent monsoonal precipitation throughout the summer left most regional rivers flowing at near-average levels but below average reservoir storage remains throughout most of the region, especially in Colorado and Utah. Coverage of drought decreased slightly during September, but still covers 64% of the region. La Niña conditions are expected to persist through most of winter and conditions during fall are likely to be warm and dry. 

September precipitation was near-to-above average in much of Utah and Wyoming and below average for most of Colorado. Southwestern Utah, central Utah and central Wyoming and northeastern Wyoming received greater than 150% of normal September precipitation. The majority of Colorado and southeastern Wyoming received less than 75% of normal September precipitation. The remnants of Hurricane Kay, at one point a category 2 storm, impacted Utah, Wyoming and Colorado on September 13-16 and monsoonal flow brought rain to the region during the last ten days of the month.

September temperatures were at least 2-4 degrees above normal throughout the entire region. Much of Utah and Wyoming experienced temperatures that were 4-6 degrees above normal in September. The regional hot spot during September was the Great Salt Lake Basin where temperatures were 6-8 degrees above normal. An early September heat wave was a major contributor to regional high temperatures. Above average monthly temperatures were driven by a significant regional heat wave from September 1-8 and much of Utah, western Colorado and western Wyoming experienced the hottest September on record.

September streamflow in most regional rivers was near-normal. Below-to-much-below streamflow was observed in northwestern and central Utah and a few other isolated reaches of rivers in Colorado and Wyoming. Reservoir storage is below average for the entire region. Reservoirs in Utah, excluding Lake Powell and Flaming Gorge, are just over 40% full which is about 75% of median October 1st water storage. In Colorado, reservoirs are 54% full which is 76% of median October 1st water storage. Wyoming reservoirs in the Bighorn, Green, Lower North Platte, Shoshone and Wind River basins are relatively full (85-100% of median storage). Reservoir storage in the Upper North Platte is at 63% of median and Jackson Lake on the Snake River is nearly empty. The large reservoirs on the Colorado River system are relatively lower than statewide storage; Flaming Gorge is 71% full (84% of median storage), Blue Mesa Reservoir is 35% full (46% median) and Lake Powell is 24% full (40% median).

Drought conditions cover 64% of the Intermountain West, a slight decrease from last month. Approximately half of Colorado and Wyoming and all of Utah are currently in drought. Drought conditions improved by one category in the Four Corners region and central Wyoming; D3 drought was removed from southeastern Utah. In southeastern Wyoming, D3 drought expanded during September.

La Niña conditions continue in the eastern Pacific Ocean as sea surface temperatures were 1-2 degrees Celsius below normal during September. There is a 60-90% probability of La Niña continuing through mid-winter 2023. NOAA seasonal forecasts suggest an increased probability of above average temperatures from October to December for the entire region. There is an increased probability of above average precipitation during October for Colorado, Utah and southern Wyoming. In Colorado, much of Utah and southeastern Wyoming, there is an increased probability for below average October-December precipitation.

Significant September weather event. Extreme September heat. A major heat wave impacted the region from September 1-8. Utah was most strongly impacted by the heat wave, but Colorado and Wyoming also saw significant impacts. The early September heat wave was perhaps the hottest September heat wave in recorded in the Intermountain West. In Salt Lake City, the all-time high temperature of 107º was tied on 9/9 for the second time this year. The first 7 days of September exceeded 100ºF in Salt Lake City and along with the last two days of August, the 9 consecutive days of 100ºF temperatures was the second-longest streak on record. Salt Lake City set the record for number of days with 100ºF temperatures in 2022 at 35 days, smashing the old record of 23 days. Elsewhere in Utah, temperatures were still extremely hot. Daily records were set at 30-60% of sites with at least 50 years of data on each day from September 1-8. Temperatures reached 112ºF in St. George on September 7. All-time September maximum temperatures were set at 55% of sites in Utah with at least 50 years of data.

The heat wave also impacted Wyoming from September 1-8. On each day from September 4-8, 30-50% weather monitoring sites in set daily record high temperatures. Similar to Utah, 53% of sites in Wyoming with at least 50 years of data set all-time record high temperatures for September. Northwest Wyoming was a hot spot with sites in Yellowstone and Teton National Park setting all-time monthly high temperatures and 100ºF was exceeded in many locations, including Casper, Cody, Sheridan, Thermopolis, Weston and Worland. Temperatures reached 106ºF in Weston, 105ºF in Worland and 104ºF in Sheridan and Thermopolis, nearly reaching all-time record high temperatures. Colorado was less severely impacted by the heat wave, but all-time September high temperatures were set at 26% of sites in Colorado with at least 50 years of data. Temperatures exceeded 100ºF in Grand Junction, Akron and Yuma and reached 99ºF in Denver and Cortez during the heat wave.

Click the link to read the article on the Water Education Colorado website (Jerd Smith):

This year’s return of summer rains provided much relief to ultra-dry soils across Colorado and helped break the heat, but the state’s streams and reservoirs remain quite low, causing concern about the upcoming water year.

Western states that rely on mountain snows monitor supplies based on a calendar that begins Oct. 1 and runs through the critical snow and spring runoff seasons. The 12-month period is known as a water year.

Soil moisture levels are the highest they’ve been since 2014, and that could improve next year’s spring runoff season, water officials said last week at a meeting of the state’s Water Availability Task Force.

Since May, the summer rainy season increased precipitation dramatically, with river basins across the state measuring precipitation that ranged from 110% to 160% of normal, according to the Natural Resources Conservation Service (NRCS).

“The big thing is how much better the summer precipitation has been and even coming into fall. That is going to make a huge difference in the soil moisture statewide,” said Karl Wetlaufer, assistant snow survey supervisor for the NRCS. “The last two to three years we’ve started winter with such dry soil moisture. But we got a really strong monsoon season and it should really, really help boost soil moisture values and that will boost runoff next spring.”

Generally, when soil moisture levels are low, more precipitation soaks into the ground, decreasing runoff. But though the wetter soils mean Colorado could derive more water when the mountain snows melt, it is unlikely to improve the water supply situation in the new water year by much.

“It’s still a very tenuous situation,” said Becky Bolinger, assistant state climatologist. “It’s not a great start to the water year.”

Despite the rains, reservoir storage is low, sitting at 78% of normal statewide. Some regions, such as the South Platte River Basin, still have near normal amounts of water in storage — the South Platte Basin sits at 97% of normal — but other regions of the state, including the southwest corner have reservoir storage that is just 65% of normal.

Streamflows too remain low. A look at the state’s eight major river basins shows that most are well below where they should be at this time of year, with the San Juan and San Miguel basins registering at just 65% of average. Streamflows in the Arkansas Basin were the healthiest, registering 102% of average.

Colorado’s situation is mirrored across the parched, seven-state Colorado River Basin.

According to the U.S. Bureau of Reclamation, the drought-strapped river system is likely to generate only 86% of its supplies, or 8.3 million acre-feet, as compared to the 30-year average, in the new water year. But the minimum probable forecast is just 49% of average, with the river system generating just 4.7 million acre-feet of water.

That is due in part to weather forecasts indicating that the fall is likely to be warm and dry again, according to Bolinger.

“The seasonal forecasts are showing that for the October, November, December time period we are likely to have a warmer than average pattern and leaning toward a drier than average pattern. It’s a big hurdle to overcome … we could quickly and easily get back into a really bad drought and low water supply situation.”

Jerd Smith is editor of Fresh Water News. She can be reached at 720-398-6474, via email at jerd@wateredco.org or @jerd_smith.

Click the link to read the article on the National Drought Mitigation website (Leah Campbell):

This summer has been one for the books with heat and rainfall records toppling around the U.S. The country experienced several “1-in-1,000” storm events in the span of just a few months, leading to devastating flooding from Kentucky to Montana. Mississippi had its wettest August on record. Nebraska had its second driest. Nineteen states had Julys that were amongst their 10 hottest in terms of average temperature, including Texas, which had its warmest July going back more than 100 years.

Drought records have also been made and broken in the last few months. In mid-September, Puerto Rico broke a streak of 91 consecutive weeks of drought when Hurricane Fiona dumped over 30 inches of rain in some places. At the end of August, over 90% of Hawaii was in drought for the first time, which continued for four weeks.

The country as a whole recently hit another sobering record: more than two years with over 40% of the contiguous U.S. in moderate drought or worse, what the U.S. Drought Monitor classifies as D1 or above. As of the latest USDM map on Oct. 4, it’s been 106 straight weeks. The last time the extent of drought in the Lower 48 dipped below 40% was on Sept. 29, 2020 (when it was a close 39.7%).

The current streak of widespread drought marks the longest such streak since the USDM began in 2000. The second longest streak, from June 2012 to October 2013, was only 68 weeks. After that is a 65-week stretch from March 2002 to June 2003. Both of those earlier periods are recognized as some of the most severe droughts on record in the U.S.

According to Brad Rippey, a meteorologist with the U.S. Department of Agriculture, the percentile ranking methodology of the USDM — where moderate drought is classified as a once per 5- to 10-year occurrence — would suggest that, statistically, drought coverage should be closer to 20% this time of year. Instead, as of the Oct. 4 map, nearly 53% of the contiguous U.S. and over 44% of the entire country and its territories, was in D1 or worse condition.

“I’ve been involved with the Drought Monitor since the beginning and have seen a lot of U.S. droughts come and go,” said Rippey. “The drought of 2020-2022 really stands out for its longevity. In 2012-2013, we were done with the worst of it in a little over a year.”

Rippey ascribes the longevity and extent of the current drought in part to back-to-back-to-back La Niña events. That “triple dip,” as Rippey calls it, has happened only two other times in the modern record, first in the mid-1970s and then the late 1990s.

La Niña and its counterpart El Niño are periodic global phenomena related to sea surface temperatures. During La Niña, the Pacific Ocean along the South American coast is cooler than normal near the equator. Meanwhile, warmer surface water is driven across the Pacific toward Asia. The movement of all that heat has significant and complex impacts on weather across the planet.

“In a general sense, when it comes to the U.S., La Niña is a drought-maker, while El Niño is a drought-breaker,” said Rippey. The current and ongoing La Niña, he explains, developed during the second half of 2020 and has generally persisted since then. The National Oceanic and Atmospheric Administration predicts that La Niña is likely to continue in the Northern Hemisphere through the end of the year at least.

Long-lasting, Extensive and Extreme

The current drought, though, isn’t just noteworthy for how long it’s lasted. It’s also been particularly widespread, fast-emerging and intense. Coverage peaked for the summer on July 12 with just shy of 45% of the entire U.S. and Puerto Rico in drought. For the contiguous U.S., it peaked closer to 52% a few weeks later. For three weeks through mid-August, in fact, 44 states across the country were at least partially in drought. Only Ohio hasn’t recorded any drought thus far this year.

(Looking at the year as a whole, drought coverage peaked back in early March at 51% and 61% for the entire U.S. and the contiguous U.S., respectively. In both cases, that’s just a few percentage points shy of the USDM record set during the 2012-2013 drought.)

In terms of speed, several states in the Southern Plains this summer had to confront what’s called “flash drought.” Through July, Arkansas, Missouri and Oklahoma all experienced a one-category-per-week degradation in drought conditions, what Brian Fuchs, a Drought Monitor author and climatologist at the National Drought Mitigation Center, says is “lightning speed by the standards of drought.” While drought tends to be a slow-onset crisis, intense heat can contribute to faster-emerging dry conditions. Indeed, Oklahoma experienced its fifth hottest July on record this year, in terms of average temperature, and Arkansas its seventh.

In Arkansas, drought coverage was not even 2% at the end of June. Just four weeks later, 89% of the state was in drought, and over a fifth was in extreme drought or D3 according to the USDM. Though conditions then began to improve, back to less than half the state in drought less than two months later, conditions degraded again in the second half of September.

These kinds of rapid changes can create significant hardship for communities and for livestock and agricultural producers. That concern is evident in the number of observations submitted to CMOR, the NDMC’s database of crowdsourced, geo-located conditions reports. As of the end of September, over 3,300 observations have been submitted to CMOR this year. Over 1,300 were from July alone, from just the three states most affected by the flash drought. In comparison, only 1,200 observations were submitted to CMOR for all of 2019 from across the whole country.

Rapid changes can also cause headaches for Drought Monitor authors trying to make sense of different environmental datasets.   

“One of the most challenging things this summer from a drought monitoring perspective has been keeping up with the different time scales drought has been occurring in different places,” said Curtis Riganti, a climatologist with the NDMC and a Drought Monitor author.

Riganti explains that they’ve been getting a lot of “mixed signals” this summer. “In the Southern Plains, there’s been flash drought over relatively wet conditions earlier in the year,” said Riganti. “In the Southwest, we’ve had the opposite problem, and it’s been a challenge to balance long-term groundwater, precipitation and reservoir deficits with the fact that it’s been a wet summer.”

With an active North American Monsoon season, drought signals in the Southwest have been particularly complex. Nevada had its third wettest August on record, and Aug. 5 was the wettest day ever in Death Valley, California, which received about three quarters of its annual rainfall in a matter of hours. Yet, years of severe drought across the region mean that water supplies are still concerningly low. On the Utah-Arizona border, for example, Lake Powell is only 25% full as of the end of September, with water levels down 16 feet from last year.

Unrelenting Heat and Hardship

Part of why drought was so intense and extensive this summer, and so difficult to deal with, was that temperatures have been sweltering in many places these last few months. Nationally, this summer was the third hottest June-August period on record, and, at the state level, several heat records were broken.

This June was the tenth hottest June on record. July was even worse. It was the third hottest July on record nationally, and almost every Western state hit top-10 records for heat for the month. The Southeast and the Midwest got some relief in August, but it was unrelenting elsewhere. Eight states in the Northeast and the Northwest all recorded their hottest August on record. In California, which had its second-hottest August, an extreme heat wave gripped the state at the end of the month, with several cities breaking records (on Sept. 5, Livermore, California hit 116 degrees, setting an all-time record for the Bay Area).

This kind of extreme heat not only drives drought, but also exacerbates its various impacts, making dry conditions more challenging. As of the latest USDM map on Oct. 4, over 126 million people across the U.S. were affected by drought. For just the contiguous U.S., the number affected was over 125 million, almost 40% of the entire population of the Lower 48. 

From the start of the year, through the end of September, the NDMC added more than 3,300 records to the Drought Impact Reporter, the center’s database of drought impacts. Each record represents a county, city or state confronting a specific challenge related to drought and dry conditions, from water restrictions and burn bans to low water levels, losses of recreation and algae blooms. Combined with the summer’s soaring inflation and rising costs for irrigation water, fuel and livestock feed, it’s been a particularly hard year for agricultural producers who have had to confront crop losses, reduced yields and insect infestations.

“Clearly something is happening to U.S. and global weather and climate patterns before our very eyes,” said Rippey. “It’s a very exciting time, but also a scary time to be a meteorologist. We may not know exactly what will happen, but all evidence says we can expect more extremes, including drought, going forward.”