#Drought news: One class degradation in NE #Colorado along the #KS #NE border

Click on a thumbnail graphic to view a gallery of drought data from the US Drought Monitor.

Click here to go to the US Drought Monitor website. Here’s an excerpt:

This Week’s Drought Summary

Several Pacific weather systems, in the form of shortwave troughs, moved in the jet stream flow across the contiguous U.S. (CONUS) during this U.S. Drought Monitor (USDM) week. The weather systems brought rain or snow to parts of northern California and the Pacific Northwest, western Colorado, the northern Plains to Mid-Mississippi Valley, and Tennessee Valley to Northeast. Rain also fell across parts of Florida. The rest of the CONUS had little to no precipitation. Even where the precipitation fell, it was mostly below normal for the week. Areas receiving above-normal precipitation included parts of the Sierra Nevada, southern Idaho, other scattered parts of the Pacific Northwest, strips across the central Palins to Ohio Valley and across New England, and parts of Hawaii. Improvement in drought conditions occurred where precipitation was above normal, while drought expanded or intensified in some areas where dryness continued. Temperatures were largely warmer than normal across the CONUS, with anomalies 9 degrees F or warmer from the Southwest to northern Plains. Parts of the Pacific Northwest and East Coast were near to cooler than normal. SNOTEL observations of mountain snowpack showed increases in snow depth in the Sierra Nevada and parts of Oregon and Washington, and snow water equivalent (SWE) values were in the high percentiles in the Sierra Nevada, and Pacific Northwest, but this is early in the snow season when the snowpack is just getting established. SWE values were in the low percentiles from Nevada eastward. Western reservoirs continued quite low, especially in Oregon, California, Nevada, Utah, Colorado, Wyoming, and New Mexico. Mounting dryness was indicated in several drought indicators and indices. Maps of 7-day, 14-day, and 28-day USGS streamflow measurements were consistent in showing below-normal streamflow from northern California, Nevada, and southern Idaho, across the Southwest, to the central and southern High Plains; across southern Texas; across western Puerto Rico; and in parts of Hawaii, Iowa, Illinois, Indiana, and the Northeast. The satellite-based Vegetation Health Index shows stressed vegetation across the California valleys and southern California, the Southwest, parts of the central Plains and Ohio Valley, and especially in southeastern New Mexico to western Texas. Where VegDRI is still in season, it shows drought across much of the West (especially the Southwest and west Texas) and parts of the Northeast. Where QuickDRI is still in season, it shows very dry conditions across the West (except for a very small part of coastal southern California) to southern and central Plains; much of Texas, and parts of the Midwest and Northeast. The KBDI shows significantly dry conditions in California, Nevada, Utah, Arizona, New Mexico, and Texas. Evapotranspiration (EDDI) for the last week has been high in the southern to central Plains, southern Alabama, and the Midwest to Northeast; at the 2- to 3-week timescales, across much of the CONUS from the Southwest to Northeast; and at longer time scales (1-3 months), in the Southwest to central Plains, and from the Ohio Valley and southern Great Lakes to Northeast. NIFC wildfire maps show large wildfires still burning in California and Colorado, several across Oklahoma, and some in other parts of the West, Kansas, Texas, Mississippi, the Florida panhandle, and central Appalachians. USGS real-time groundwater level data show low groundwater at points across the West, in northern Indiana, southern Georgia, and parts of the Northeast. NASA GRACE satellite-based groundwater estimates show low groundwater across most of the West to central and southern High Plains, most of New York to New England, much of Texas, and parts of North Dakota, Pennsylvania, Virginia, Alabama, and Florida. Soil moisture is dry across the West from California to the southern and central Rockies, in the southern and central High Plains, in North Dakota, across Nebraska and Iowa, across central Illinois to northern Indiana, parts of Pennsylvania and New York, and (for some indicators) most of New England and southern Alabama (CPC, NLDAS, and UCLA/VIC models; satellite-based AAFC/SMOS, GRACE, and NASA/SPoRT analyses). The Standardized Precipitation Index (SPI) shows dry conditions in various places at different time scales. These include North Dakota to Minnesota, Wyoming, New England, and southern Texas to the Lower Mississippi Valley (at the 1-month time scale); California to the central and southern Rockies, much of the Great Plains, Iowa and Missouri to Indiana, parts of the Northeast, and southern AL (2 to 4 months); California to the central and southern Rockies, much of the Great Plains, Iowa, Indiana to Ohio and Michigan, most of Northeast (6 to 12 months); parts of Pacific Northwest (9 to 12 months); and the Southwest to southern and central High Plains, and parts of Pacific Northwest, Texas, Iowa, Indiana, and the Northeast (24 months). When the desiccating effects of hot temperatures are included, the Standardized Precipitation Evapotranspiration Index (SPEI) shows more intense drought conditions over the SPI dry areas than indicated by the SPI…

High Plains

Half an inch of precipitation fell over parts of western Wyoming and the Colorado mountains, with a strip of half-inch precipitation bisecting Kansas. But for most of the region, it was a dry week with less than a quarter inch falling or no precipitation. Moderate and severe drought was trimmed slightly in western Wyoming, but the big story was expansion of severe and extreme drought in parts of Kansas and Nebraska; moderate drought also expanded in eastern Kansas. This expansion was prompted by several indicators, including SPI at several time scales and multiple soil moisture tools. According to USDA reports, half to two-thirds of the topsoil moisture was short to very short in all of the High Plains states except Colorado, where 87% of the topsoil moisture was short to very short. USDA statistics show that 43% of the winter wheat was in poor to very poor condition in Colorado, which is a jump of 11% compared to a week ago. In Nebraska and Kansas, the winter wheat statistics were 20% and 26%, respectively, poor to very poor…

West

Parts of northern California and the Sierra Nevada and the western parts of Oregon and Washington received half an inch to over 2 inches of precipitation this week, with locally over 4 inches in Oregon and Washington. Parts of the Rocky Mountains received half an inch to 2 inches. While beneficial, the precipitation was not enough to overcome deficits that have built up over much of 2020. An exception was contraction of abnormal dryness in a couple spots in Washington. Moderate drought retreated in central Montana, reflecting moisture which has fallen in recent weeks. Severe to extreme drought were expanded in parts of northeast California, northwest Nevada, and adjacent Oregon where precipitation this week was light and deficits over the last several months continued to mount.

Southern portions of the West region received little to no precipitation this week. Moderate to severe drought expanded in the San Joaquin Valley and abnormal dryness expanded in southern California. The failure of the summer monsoon resulted in record dryness to the Southwest states, and record heat over warm season increased evapotranspiration, resulting in record SPEI values over the last 3 to 6 to 9 months. The SPEI values were not only record, they exceeded previous records by huge margins. Extreme to exceptional drought expanded to reflect this prolonged dryness in Arizona, New Mexico, and Nevada. According to USDA reports, topsoil moisture was short to very short across 81% of New Mexico, 75% of California and Utah, 58% of Montana, 55% of Idaho, and 40% of Nevada and Oregon. Parts of interior southern California, the southern Great Basin, and the Desert Southwest have had a seven-month dry streak. According to National Weather Service records, the last measurable precipitation in Bishop, California occurred on April 17, 2020, and the last measurable precipitation in Las Vegas, Nevada occurred on April 20, 2020…

South

Half an inch or more of rain fell across parts of Oklahoma and Arkansas, but other than that the South region was dry. Abnormal dryness expanded in parts of all of the states in the South region. Moderate to exceptional drought were expanded across various parts of Texas; moderate drought was introduced in Arkansas and Mississippi and expanded in Louisiana; and moderate and severe drought expanded in Oklahoma. In the Oklahoma panhandle, moderate and severe drought retreated. According to USDA reports, topsoil moisture was short or very short across 69% of Texas, 41% of Oklahoma, 31% of Mississippi, 24% of Louisiana, and 14% of Arkansas; 38% of the winter wheat was in poor to very poor condition across Texas…

Looking Ahead

The jet stream will continue to be active during the next couple weeks, sending a parade of Pacific weather systems into the CONUS. For November 25 to December 1, precipitation will fall across the Pacific Northwest, where the coastal mountains may receive over an inch of precipitation, and widespread precipitation is forecast to fall from the southern Plains to East Coast. Amounts may exceed 3 inches from southeast Texas to the southern Appalachians and parts of New England, with an inch or more surrounding these core areas from Texas to Kansas, from the Gulf Coast to Great Lakes, and from the Florida panhandle to the Northeast. A fourth of an inch or less is forecasted to fall across most of the West, from the northern Plains to Upper Mississippi Valley, and over much of Florida. The forecast models predict above-normal temperatures east of the Rockies with near to below-normal temperatures across the West. The outlook for December 2-8 is mostly dry. Odds favor below-normal precipitation across most of the CONUS, with only the Rio Grande Valley and eastern two-thirds of Alaska having odds favoring wetter-than-normal conditions. Odds favor warmer-than-normal temperatures across the West, central to northern Plains, Great Lakes, and eastern Alaska, with below-normal temperatures likely across the southern Plains, Southeast, Mid-Atlantic, and western Alaska.

US Drought Monitor one week change map ending November 24, 2020.

“…all signs point to a future where every competing water use is a valid one and there isn’t enough water to quench them all” — Joanna Allhands #ColoradoRiver #COriver #aridification

From AZCentral.com (Joanna Allhands):

Opinion: We’ve known for years that a shortage is coming, but it’s alarming how quick the conditions are changing. The Colorado River system was not set up for this.

Glen Canyon Dam aerial. Photo credit: USBR

This warm, dry weather we’ve been having may be good for moving activities outside.

But it’s bad news for our water supply.

The chances are growing – and quickly – that a warm, dry winter could push Lake Powell to a trigger point about a year from now that could result in significantly less water for Lake Mead, which supplies about 40% of Arizona’s water supply.

That likely would push Mead into a first-time shortage declaration. And if the same thing were to happen the following year, it would likely plunge Mead into a more severe shortage – a depth from which the lake is unlikely to recover any time soon.

Like I said, bad news.

Why would Mead get less water?

The 2007 operational guidelines lay out how much water is released from the upstream Powell to the downstream Mead. In “normal” years (and yes, I use quotes because nothing about the Colorado River is normal these days), Mead gets about 8.23 million acre-feet.

That drops to 7.48 million acre-feet once Powell’s levels fall below a certain depth. This occurred once before, in 2014, and luckily, Mead was nowhere close to a shortage then.

But lake levels plunged that year and never recovered, even in wet years and despite millions of acre-feet of water that Arizona and others have stored in Mead.

The lake is currently less than 10 feet above its shortage elevation trigger of 1,075 feet. Yet a 7.48 million acre-feet release in water year 2022, which begins in October 2021, could drop levels on Lake Mead by nearly 20 feet.

That could plunge us into shortage

That would place us solidly into a Tier 1 shortage – which for Arizona, means no more Colorado River water for Pinal famers and some water lost from the non-Indian agricultural (NIA) pool, which is a rung higher on the priority list and despite its name, mostly supplies tribes and cities.

Should conditions persist and Mead get another 7.48 million acre-feet release in water year 2023, that would likely plunge us deep into a Tier 2 shortage, nixing most of the NIA water that some cities use for existing development and others had wanted to shore up their long-term supplies.

Without that water, cities will need to find other, more secure sources. Which means if the battle to transfer water from on-river communities to Queen Creek is fierce now, new ones are likely to get a lot fiercer.

How likely is this 7.48 scenario?

We’ve known for years that a shortage would eventually come to Lake Mead, and that when that happens, Arizona – the state with junior water rights – would be the first to face more severe consequences.

But it’s alarming how quickly the conditions are changing.

The chances of a 7.48 million acre-feet release have increased markedly – from less than 20% in April to more than 50% in August, depending on which hydrology forecast you use. The chances of a Tier 1 shortage on Mead were as high as 30% in August, up from roughly 10% in April.

That may not sound like a lot, but it’s enough to keep risk-adverse water managers up at night. Consider that a 1 in 5 chance of Lake Mead tanking was enough to drive ratification of the Lower Basin Drought Contingency Plan, which buys time for the lake through mandatory cuts to our water supply.

So, what is provoking such quick forecast changes?

Last winter was relatively wet. It looked like we were on par for an average runoff year. But the ground was dry before all that snow fell, and as it began to melt, a lot of it sunk into the parched soil.

In the space of a few weeks, what looked like a decent runoff year turned into a mediocre one.

Then we had a record-breaking hot and dry summer. The soil is again parched.

But, unlike last winter, we are now in a relatively strong La Nina weather pattern, which historically has meant warm and dry winters for all but a small corner of the Colorado River basin.

It’s a double whammy. If this winter plays out as expected, we’ll have a meager snowpack that is unlikely to produce much runoff because warm winds blowing over the snow can suck out moisture. And much of what is produced could sink into the ground before it ever makes it to our reservoirs.

If this is the future, then what?

It’s early in the snow season, of course. Things could change.

But while few parts of the Colorado River basin were facing drought conditions a year ago, most are now in extreme or exceptional drought, the most severe categories.

And some worry that this could be the beginning of a multiyear string of similar dry conditions – a la what we saw most recently in 2012-13, the lead-up to the last 7.48 million acre-feet release on Powell.

The good news, if you want to call it that, is that Arizona’s water leaders already assumed that we’d already be in a Tier 1 shortage by now. We have plans to handle these shortages in the short term, even if the details – like forcing Pinal farmers back solely on groundwater – are less than ideal.

The more daunting challenge lies in 2026, when the drought contingency plan and the 2007 guidelines expire. Because, as bad as this winter may look, the science suggests we are in for many more of them as the Colorado River basin gets warmer and drier.

We have a system that assumes water allocations will be steady as she goes, when the best-case scenario may be one of feast or famine.

And all signs point to a future where every competing water use is a valid one and there isn’t enough water to quench them all.

How do we decide who gets what when a dwindling supply becomes even more volatile? That is the fundamental question we must now address.

Reach Allhands at joanna.allhands@arizonarepublic.com. On Twitter: @joannaallhands.

Record #Denver snowfall is rare for multiple reasons — The Denver Post #snowpack

From The Denver Post (Ben Reppert):

Denver International Airport tallied 5 inches of snow. This is a record daily snowfall for Nov. 24, breaking the old record of 4 inches set in 1946. Even more notably, it was the first daily November snow record to fall in the city since 1994. Snow totals across the rest of the metro area generally range from 3 to 6 inches, with heavier amounts up to 10 inches in the western suburbs.

This was a rare November snowstorm in the Denver area beyond the record-breaking amount. Another rarity lies within the heavy and wet nature of the snow…

The overall air mass above the surface was rather mild for this time of year. At the beginning of the storm, a large layer of the atmosphere above our heads was flirting with the freezing mark. The air mass sitting over the state also had quite a bit of moisture in it. The total amount of water in the air was nearly double the normal amount for late November.

This combination of a mild and moist air mass in place led to snow reaching the ground with an extremely high water content. Heavy, wet snow is something that Denver would expect in early and late season storms, such as in September or April. Winter’s chill is typically well established by late November, promoting very powdery snow.

Extra water in this snow is certainly beneficial for Colorado’s ongoing drought. The snow melted down to just under a half of an inch of liquid at DIA. This makes it Denver’s wettest day since Sept. 8, and the fifth wettest day in all of 2020.

CoCoRaHS map for November 24, 2020.
CoCoRaHS map for November 25, 2020.

#Colorado Looking to Issue Comprehensive Guidance for Waters of the United States (#WOTUS) — Lexology

Photo credit from report “A Preliminary Evaluation of Seasonal Water Levels Necessary to Sustain Mount Emmons Fen: Grand Mesa, Uncompahgre and Gunnison National Forests,” David J. Cooper, Ph.D, December 2003.

From Lexology.com (Spencer Fane):

How is Colorado Dealing with “Gap” Waters?

The scope of federal jurisdiction under the Clean Water Act remains perplexing, particularly now that Colorado is the only state in the nation where the Navigable Water Protection Rule did not take effect June 22, 2020. In the context of a lengthy “stakeholder” process, on November 20, 2020, the Colorado Department of Public Health and Environment (CDPHE) issued a White Paper addressing its regulatory options in light of the new federal WOTUS rule. Construction companies, developers, and other businesses seeking to permit activities around wetlands, ephemeral waters, and intermittent streams in Colorado would benefit from reviewing this comprehensive discussion of the multitude of dilemmas Colorado and others states face in light of the new rule.

See White Paper here.

The state’s White Paper includes background on these topics –

  • Federal permitting including Section 402 and 404 permits.
  • State waters and the state’s regulation of discharges to state waters.
  • The Supreme Court’s Rapanos decision and subsequent guidance.
  • The 2020 Navigable Waters Protection Rule.
  • Litigation of the 2020 Navigable Waters Protection Rule.
  • And perhaps most importantly –

  • Potential impacts of the 2020 Navigable Waters Protection Rule if it were to go into effect in Colorado.
  • Of most significance in terms of the impacts to state regulatory programs, the White Paper states:

    The rule includes several definitions that further limit how the EPA and the Corps will define WOTUS in contrast to the existing regulatory framework. First, it restricts the definition of protected “adjacent wetlands” to those that “abut” or have a direct hydrological surface connection to another jurisdictional water “in a typical year.” 33 C.F.R. § 328.3(c)(1); 40 C.F.R. § 120.3(3)(i). Wetlands are not considered adjacent if they are physically separated from jurisdictional waters by an artificial structure and do not have a direct hydrologic surface connection. The 2020 Rule also limits protections for tributaries to those that contribute perennial or uncertain levels of “intermittent” flow to traditional navigable waters in a “typical year,” a term whose definition leads to additional uncertainty. 33 C.F.R. § 328.3(c)(12); 40 C.F.R. § 120.2(3)(xii); 33 C.F.R. § 328.3(c)(13); 40 C.F.R. § 120.2(3)(xiii).

    Collectively, these new definitions in the 2020 Rule will reduce the scope of waters subject to federal jurisdiction in Colorado far below that of the 2008 Guidance. The state waters that would no longer be considered “waters of the United States” under the 2020 Rule have been referred to as “gap waters” and are further described in Section II below. Historically, not all of Colorado’s state waters have been considered WOTUS. However, the [CDPHE] has maintained that the number of state waters considered WOTUS under the 2008 Guidance is far more than would be considered WOTUS under the 2020 Rule. [Emphasis added.]

    Colorado Rivers. Credit: Geology.com

    2020 Annual Meeting of the #ArkansasRiver Compact Administration (ARCA), December 9, 2020

    NOTE: Updated meeting link from Kevin Salter Click here.

    From email from the Arkansas River Compact Administration (Kevin Salter):

    Arkansas River Basin via The Encyclopedia of Earth