Day: September 26, 2019

#Drought news: Abnormal Dryness (D0) and Moderate Drought (D1) increased in parts of SW #KS, south-central and western #Colorado due to increasingly dry conditions over the past 90 days (30-50 percent of normal)

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

US Drought Monitor September 24, 2019.
US Drought Monitor September 24, 2019.
West Drought Monitor September 24, 2019.
West Drought Monitor September 24, 2019.
Colorado Drought Monitor September 24, 2019.
Colorado Drought Monitor September 24, 2019.

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

This Week’s Drought Summary

Rapidly intensifying “flash drought” — attributed in part to extreme late-summer heat — continued to afflict many areas from the lower Midwest and Mid-Atlantic States to the Gulf Coast. Conversely, heavy to excessive rainfall associated with the remnants of Tropical Storm Imelda eradicated drought but caused locally catastrophic flooding in southeastern Texas and western Louisiana. Farther west, late-season showers on the heels of an abysmal Southwestern monsoon (to-date) helped stem drought increases in the Four Corners region, while rain and mountain snow further reduced lingering drought in the northwestern quarter of the nation. Meanwhile, additional moderate to heavy rain eased or alleviated dryness and drought from the Northwest into the Great Lakes. Outside of the lower 48, additional heavy rainfall eased lingering drought and dryness in south-central Alaska. Elsewhere, short-term drought persisted across the Hawaiian Islands, while Puerto Rico was mostly dry; rain arrived in Puerto Rico after the monitoring period ended (Tuesday morning)…

High Plains

Most of the region remained free of drought, as above-normal temperatures in the east contrasted with cool albeit dry conditions in the west. However, Abnormal Dryness (D0) and Moderate Drought (D1) were increased in parts of southwestern Kansas as well as south-central and western Colorado due to increasingly dry conditions over the past 90 days (30-50 percent of normal)…

West

Moderate to heavy showers arrived in the Southwest, while unsettled, cool conditions continued across the Northwest.

Showers and thunderstorms (1-4 inches, locally more) associated in part with moisture from the remnants of Hurricane Lorena arrived in central Arizona, helping to stem further drought increases (at least temporarily) from the abysmal Southwestern monsoon season-to-date. Despite this week’s showers, 6-month rainfall has totaled a meager 10 to 50 percent of normal, with higher totals (70-100 percent of normal) noted in the mountains of central Arizona. The Southwestern monsoon typically runs from June 15-September 30 and accounts for up to half the total annual precipitation in some parts of the Southwest.

Farther north, near- to below-normal temperatures as well as another round of moderate to heavy rain (1-3 inches) from the Pacific Northwest into the northern Rockies spurred additional reductions of Abnormal Dryness (D0) and Moderate Drought (D1). At week’s end, D0 and D1 were limited to locales still reporting longer-term precipitation deficits (12-month precipitation averaging near 75 percent of normal or less)…

South

Highly variable conditions were observed across the South, with intense late-summer heat and acute short-term dryness in southwestern and northeastern portions of the region contrasting with heavy to excessive rainfall across the west-central Gulf Coast and from western Texas northeastward into central and southern Oklahoma. Tropical Storm Imelda moved slowly ashore near Freeport, Texas, drifting northward while producing prodigious rainfall totals (20-30 inches, locally more) south and east of Houston. Heavy rain (2-8 inches) was also noted further inland across eastern Texas, western Louisiana, and southeastern Oklahoma, easing or alleviating Abnormal Dryness (D0) as well as Moderate to Severe Drought (D1 and D2). Farther west, widespread heavy showers (1-5 inches, locally more) from Texas’ Big Bend northeastward into central and southeastern Oklahoma (a peak value of 7.66 inches was noted in Antlers, OK) likewise supported aggressive reductions to drought intensity and coverage.

Conversely, excessive heat (daytime highs approaching or topping 100°F) and pronounced short-term dryness (60-day rainfall totaling locally less than 20 percent of normal) heightened evapotranspiration rates and soil moisture losses, resulting in quickly escalating drought impacts (often referred to as a “flash drought”.) It should be noted that “flash drought” impacts often arise more quickly than the rainfall data would suggest due to the accompanying heat. For this week’s analysis, the expansion of D0 (Abnormal Dryness) as well as Moderate (D1) to Extreme Drought (D3) was driven by guidance from local experts, impact reports from observers, as well as temperature- and rainfall-driven data products which focused on the past 60 to 90 days. Increases in drought were most pronounced from the Rio Grande toward Dallas, Texas, and from the central Delta into Tennessee. State-wide average topsoil moisture was rated more than 70 percent short to very short (according to USDA-NASS) as of September 22 in Arkansas (78 percent poor to very poor), Mississippi (83 percent), and Tennessee (89 percent, a 14-point jump over last week)…

Looking Ahead

The overall theme of a persistent and stagnant weather pattern will continue into next week. High pressure will maintain dryness and drought from New England to the Gulf Coast Region, though a series of weak cold fronts may provide chances for much-needed shower activity from eastern portions of Kentucky and Tennessee to the central Atlantic Coast. Likewise, mostly dry weather is expected from the Southwest into the central Rockies and Great Plains. In contrast, wet weather will continue from the Northwest into the northern Plains and upper Midwest, with another ribbon of moderate to heavy rain (locally more than 2 inches) possible from the southern High Plains into the Great lakes Region. The NWS 6- to 10-day outlook for October 1–4 calls for above-normal temperatures across the eastern half of the nation in addition to the southern Plains and western Gulf Coast region, while cooler-than-normal weather prevails from the Pacific Coast into the upper Midwest. Near- to above-normal precipitation across much of the nation will contrast with drier-than-normal conditions across the southeastern quarter of the nation.

Here’s the 90-day change map for the West.

#COleg: Upper #ColoradoRiver Basin demand management program update, Interim Water Resources Committee meeting recap #COriver #aridification

Changing nature of Colorado River droughts, Udall/Overpeck 2017.

From Water Education Colorado (Larry Morandi):

A local legislator is questioning the need for a new drought contingency plan on the Colorado River that would help boost supplies in Lake Powell and protect the state against a future demand for its water from California, Arizona and Nevada.

State Sen. Jerry Sonnenberg, R-Sterling, has questioned a possible water conservation plan that could become part of the drought plan that all seven states that share the river – Wyoming, Utah, New Mexico, Colorado, Arizona, Nevada and California – signed earlier this year.

As part of that agreement, the Upper Basin states —Colorado, Utah, Wyoming and New Mexico — were for the first time ever given the legal right to store extra water in Lake Powell that is not subject to mandatory releases to the Lower Basin’s Lake Mead. The storage pool is authorized to hold up to 500,000 acre-feet of water — enough for roughly 1 million homes — and could help the Upper Basin meet future obligations to the Lower Basin during an especially dry period on the river.

But now the Upper Basin states are exploring whether it makes sense to create a so-called demand management program that would pay farmers and cities to voluntarily and temporarily slash their water use —and be compensated for it — and to take that saved water and put it in Lake Powell.

Sonnenberg has questioned the need for the program, saying that as long as Colorado complies with the rules of the 1922 Colorado River Compact, its water users should be protected by the courts from any legal demands from the Lower Basin states.

“Are we worried that the Supreme Court would not hold our compact to the letter of the law?” Sonnenberg asked. His questions came during a meeting earlier this month of the state legislature’s Interim Water Resources Review Committee.

In fact, the main concern isn’t the terms of the 1922 compact, but the ability of the Colorado River to continue supplying the 40 million people who rely on its flows. If flows drop too low, due to ongoing drought and climate change, then the Upper Basin might have difficulty meeting its compact obligations to the Lower Basin, putting its water users at risk. Agriculture producers and communities across the state rely on the Colorado River, and major metropolitan areas, including Denver, import Colorado River water to serve their residents and industries.

But Sonnenberg isn’t alone. The likely focus on ag cutbacks troubles Rep. Marc Catlin (R-Montrose), former manager of the Uncompahgre Valley Water Users Association.

“We’re still looking at agriculture as a living reservoir that we don’t have to build,” he said, “because we can just keep chipping away at the acreage.”

And Catlin questioned the temporary nature of the program, citing testimony from earlier in the meeting by Colorado State University climate scientist Brad Udall suggesting stream flows throughout the Colorado River Basin will continue to drop due to higher temperatures, earlier runoff and reduced snowpack, creating a permanent, rather than temporary, need for the water.

Rebecca Mitchell, director of the Colorado Water Conservation Board (CWCB), said the water-saving effort could give everyone breathing room, so that if and when Colorado River supplies drop, the seven states can manage the issue themselves, rather than relying on the courts.

Since irrigated agriculture consumes 85 percent of water in the West, cutting back farm water use to fill the Lake Powell pool is one method that would most likely be used if Colorado ultimately decides to create this conservation program. Mitchell and her agency have committed that no matter the shape the program takes it would be voluntary, temporary, and compensated.

Andy Mueller, general manager of the Glenwood Springs-based Colorado River Water Conservation District, said he isn’t sold on the need for the conservation program, but that Colorado water users need to be looking ahead in order to be prepared. “The concern has to be where we are headed right now,” he said.

Surplus deliveries to the Lower Basin from high water years in 2011 and 2012 have dropped off, he noted, and “we can see a rising risk of the Upper Basin being in a position where we may violate the compact.”

Committee chair, Sen. Kerry Donovan (D-Wolcott), committee chair, said the uncertainty that lies ahead should be dealt with now, “We don’t know [the potential for a compact call] but not knowing that, and the significance of the issue we’re dealing with, is motivation enough to not go through the experience of learning the answer after (we spend) years in the court system.”

The CWCB, which has convened a series of public work groups to study the feasibility of the new drought pool, has not set a deadline for a decision on the program.