‘#ClimateChange is water change’ — why the #ColoradoRiver system is headed for major trouble #COriver — The Washington Post

Drought affected Lake Mead via the Mountain Town News
Drought affected Lake Mead via the Mountain Town News

From The Washington Post (Chelsea Harvey):

… the last time the lake was at full capacity, with water levels 1,225 feet above sea level, was in 1983. Since then, and particularly since the year 2000, its surface levels have been steadily dropping, leaving behind a striking white “bathtub ring” around the shoreline showing how the water levels have decreased over the years. Currently, demand on Lake Mead has been removing more water than is being replenished, resulting in a deficit of about 1.2 million acre-feet, or about 400 billion gallons, each year.

According to federal guidelines, a shortage is to be declared at the start of any given year if Lake Mead’s water levels have sunk below 1,075 feet above sea level. The new federal projections, spanning the next 24 months, suggest that the elevation will be hovering just below 1,079 feet at the end of this December.

By the end of December 2017, however, the report predicts that water levels will have sunk to about 1,074 feet. If this occurs, the federal government will declare a shortage and affected states will be obligated to reduce their water consumption.

Avoiding a shortage in 2017 can be viewed as a temporary victory, said Jennifer Pitt, the National Audubon Society’s Colorado River project director.

“Were it not for some extraordinary efforts by lower basin water users in California, in Arizona, in Nevada and in Mexico to reduce their use of water already, we would in fact have seen a shortage in the lower basin,” she said.

In 2012, the U.S. and Mexico entered into an agreement known as Minute 319, a cooperative water management plan under which Mexico has been storing water in Lake Mead to help bolster the reservoir’s falling water levels. Under the agreement, Mexico agreed to take part in both surpluses and shortages as they’re declared for the reservoir. The agreement is set to expire next year, but officials have already opened negotiations to potentially extend it.

And in 2014, the Bureau of Reclamation launched the Pilot System Conservation Program in cooperation with states in the lower Colorado River basin, which has involved a number of projects in California, Nevada and Arizona aimed at conserving water through storage initiatives and demand reduction. The agency estimates that the projects approved so far will have conserved more than 50,000 acre-feet of water — approximately 16 billion gallons — by the end of this year.

However, the projections for 2018 serve as a stark reminder that there’s still work to be done.

“I think it is a short-term success that we’ve avoided shortage this year, but it is a very clear reminder how close we are to the edge,” said Taylor Hawes, The Nature Conservancy’s Colorado River program director. “We are all in this together. It’s not just a lower basin problem, it’s a full basin problem, including Mexico and the upper basin. And we need to be developing solutions that work for all sectors and work toward long-term sustainability.”

Such solutions will likely be all the more important in the face of future climate change, according to Brad Udall, senior water and climate research scientist at Colorado State University’s Colorado Water Institute.

For the past 15 years, a combination of precipitation declines and unusually high temperatures have helped fuel the region’s ongoing drought.

“Because you have these warmer temperatures, you then get a whole bunch of other processes at play,” Udall said. “You get a higher evaporative load from soil, you get plants that green up sooner and use more water, you get more evaporation out of reservoirs, you get a longer growing season on both the spring and the fall ends. All of that leads to declines in runoff.”

Melting snowpack in the Rocky Mountains is the primary source of water replenishing Lake Mead and the other reservoirs each spring. But recent declines in precipitation mean there’s less snowpack available to melt in the first place. And thanks to the high temperatures in the region, what snow there is has been melting earlier, which adds to the problem. Typically, it’s best when the snow melts all at once as late in the season as possible, Udall said. When it melts sooner, it can trigger an early growing season for plants, which then suck up more water throughout the course of the spring than usual. This effect takes away from the water that runs off into the reservoir and can also contribute to longer fire seasons and increased evaporation of water from the soil, all of which also feed drought. And, more simply, an earlier melt can also result in lower water flow later in the summer, when water is needed the most.

These changes are “clearly climate change at work,” he said, adding, “Climate change is water change. This is the primary way by which we tiny little humans are going to get to feel the impacts of climate change. The water cycles will change.”

It’s still unclear how the region’s hydrology will continue to evolve as it continues to heat up. Climate models have presented a mixed bag of future scenarios, Udall noted. But so far, the warmer temperatures seem to be linked to long-term declines in flow. And Udall added that recent research has also suggested that future warming may increase the potential for “megadroughts” — droughts that last for decades, rather than just a few years.

“These warmer temperatures make it a lot easier to push the system into a dryness state that’s hard to escape from,” he said.

This year and last year, unusual weather events in the spring helped the river system avoid an otherwise impending shortage, Udall pointed out.

“In 2015, on April 1, the runoff forecast was for 74 percent of normal,” he said. “It was a pretty grim forecast.”

However, the country as a whole went on to experience an unusually wet May, which Udall said “bailed the system out from what would have been an earlier shortage declaration for sure.” This year, he said, a similar situation occurred.

But it’s not a phenomenon the western states should count on in the future, he added. There’s still a very real possibility that a shortage will occur in 2018, and a continuation of the water conservation initiatives undertaken so far — along with additional efforts — will be crucial to avoid a crisis.

Some experts have suggested implementing a policy in which lower basin states — Arizona in particular — would accept steeper cuts to their annual Colorado River water allocation while the reservoir still remains at higher elevations. A 2009 paper, which Udall co-authored, suggested that such aggressive tactics could significantly reduce the probability of crisis through at least mid-century.

This “drought contingency plan” is still a matter of discussion among the lower basin states and the Bureau of Reclamation, but some experts feel that its adoption is crucial to avoiding future crises.

“It is imperative that the three lower basin states adopt the lower basin drought contingency plan to stabilize the Colorado River supply and to give water users certainty about what their supplies will be in the future,” said Pitt of the National Audubon Society.

Ultimately whatever solutions are adopted in the future, experts agree that they must be a collaborative effort among all the beneficiaries of the Colorado River system.

“The sort of geopolitical reality of the Colorado River is that we’re all in it together,” Pitt said. “And all water users and all jurisdictions are going to have to work together to ensure that our water supply is stabilized and our uses don’t exceed what this river has to give.”

Colorado River Basin, USBR May 2015
Colorado River Basin, USBR May 2015

August 2016 ENSO update: Wavy gravy — NOAA

From Climate.gov (Emily Becker):

It’s August already, El Niño is long gone, and we’re still stuck in neutral. Is La Niña on the way? And is anything interesting going on in the tropical Pacific?

Currently, forecasters think there’s a slightly better than 50% chance of La Niña developing in August–October and then a 55-60% chance during the winter. Right now, it looks like if La Niña does manage to form and last the five consecutive, overlapping seasons necessary to qualify as an ENSO event, it’s likely to be a weak one.

Let’s start by checking in with current conditions. During July, sea surface temperature in the Nino3.4 region of the tropical Pacific was -0.21°C (-0.38°F) below average, according to ERSSTv4, the dataset we use for all our forecast verification. You may have also seen the monthly value for July from the OISST dataset, which was -0.49°C below average. Which one’s right?

Check out Tom’s post for details, but in short, these two datasets have different geographic detail: ERSSTv4 is lower resolution, while OISST has a finer grid with more spatial detail. Since the current area of colder-than-average water is a narrow strip along the Equator, the average over the Niño3.4 region can be different depending on the dataset.

Sea surface temperature in July 2016 compared to the 1981-2010 average. Cooler-than-average waters are present in the central tropical Pacific. NOAA Climate.gov map, based on GEO-Polar data.
Sea surface temperature in July 2016 compared to the 1981-2010 average. Cooler-than-average waters are present in the central tropical Pacific. NOAA Climate.gov map, based on GEO-Polar data.

I realize I haven’t answered the question “which one is right?” That’s because they both are–they’re just different. We use the ERSSTv4 for all our long-term monitoring, because it has been carefully quality-controlled and extends back to 1950. OISST is used as the starting point for a lot of climate models, because it has daily data available, and has that higher resolution. The finer detail in the OISST also allows it to pick up on smaller-scale changes like the current cool Niño3.4 index.

Situation Neutral
July’s tropical atmosphere mostly looked like neutral conditions, too, with nearly average winds across the tropical Pacific region. There have been some hints of more rain than average over Indonesia, and less over the central Pacific, as well as a slightly positive trend in the Southern Oscillation Index and Equatorial Southern Oscillation Index. These might be early hints of a La Niña pattern… or might just be short-term changes. So we’re playing a waiting game right now.

Like we did with El Niño, we have to see a certain set of conditions before we can declare the onset of La Niña. First, the monthly Niño3.4 index needs to drop to or below -0.5°C. It’s close, but not there yet. After that, we need to see forecasts that it will stay below that threshold for five overlapping three-month periods (“seasons”). Finally, we need to see the right response from the atmosphere: a strengthened Walker circulation, meaning stronger surface easterly and upper-level westerly winds over the equatorial Pacific Ocean, lower-than-average pressure and more rainfall over Indonesia, less rainfall over the central Pacific, and higher-than-average pressure in the vicinity of the eastern Pacific.

Flowchart showing decision process for determining La Niña conditions. Figure by Fiona Martin, adapted by Climate.gov.
Flowchart showing decision process for determining La Niña conditions. Figure by Fiona Martin, adapted by Climate.gov.

What did one ocean say to the other? Nothing, it just waved.
If you look at the map of one-week average sea surface temperature, you may have noticed an interesting feature along the eastern and central equatorial Pacific: a series of waves along the edge of the “cold tongue”. The cold tongue (that term always gives me the heebie-jeebies) is a narrow strip of cooler water right along the Equator that’s present during neutral and La Niña conditions, and is strongest between July and November. It comes from deep ocean water that rises up near the South American coast, and is then spread westward by surface currents. El Niño’s warming reduces the cold tongue.

Sea surface temperature on July 23, 2016. The eastern Pacific cold tongue is clearly visible along the Equator, surrounded by warmer waters to the north and south. The wavy features along the northern and southern borders between the cold tongue and the warmer waters are tropical instability waves. The waves on the north side are clearer in part due to the stronger temperature gradient on that side of the cold tongue. Map by NOAA Climate.gov from CDR data.
Sea surface temperature on July 23, 2016. The eastern Pacific cold tongue is clearly visible along the Equator, surrounded by warmer waters to the north and south. The wavy features along the northern and southern borders between the cold tongue and the warmer waters are tropical instability waves. The waves on the north side are clearer in part due to the stronger temperature gradient on that side of the cold tongue. Map by NOAA Climate.gov from CDR data.

The waves near the cold tongue are called tropical instability waves, and they were first noticed in 1977, at the beginning of the satellite era (1). They’re occasionally called Legeckis waves, after the scientist who first observed them. They emerge and move west over a few weeks, so they tend to get washed out in a monthly or seasonal average temperature anomaly map.

Tropical instability waves are partly a result of the difference in temperature between the cold tongue and the waters just north and south of the Equator. The interface between the colder and warmer water is called a front, just like the cold and warm fronts we see in the atmosphere. Whenever you have sharp differences in temperature, nature wants to mix it up to even things out, creating the conditions for waves to form. During La Niña, the cold tongue is cooler than average, and the fronts are intensified, usually leading to stronger tropical instability waves.

Tropical instability waves aren’t just an end result, though: they mix warmer water in to the cold tongue and interact with the atmosphere, affecting winds and surface pressure. ENSO influences the development of the waves (by affecting the north-south temperature gradient between the cold tongue and the off-equatorial water), and the waves and their atmospheric interaction can influence the characteristics of ENSO. Some researchers have found that, since tropical instability waves are prominent during La Niña, the effect of mixing the warmer waters in to the cold tongue can reduce the amplitude of La Niña (2).

A lot of research has been done to understand these waves and their interaction with ENSO, and there is some evidence that including them in the observations used as starting points for climate models can result in improved forecasts (3, 4). However, they’re just one feature of an immensely complicated system. For now, we’re back in borderline territory, and still in a La Niña Watch. We’ll continue keeping a close eye on both the tropical Pacific and computer model forecasts, and keep you posted on changes.

Many thanks to my colleagues Caihong Wen (Climate Prediction Center) and Jim Carton (University of Maryland, College Park) for their assistance with this post.

References
(1) Willett, C.S., R.R. Leben, and M.F. Lavin, 2006: Eddies and Tropical Instability Waves in the eastern tropical Pacific: A review, Progr. Oceanogr., 69, 218-238.

(2) Im, S.-H., S.-I. An, S. T. Kim, and F.-F. Jin (2015), Feedback processes responsible for El Niño-La Niña amplitude asymmetry, Geophys. Res. Lett., 42, 5556–5563, doi:10.1002/2015GL064853.

(3) Caihong Wen, Yan Xue, and Arun Kumar, 2012: Ocean–Atmosphere Characteristics of Tropical Instability Waves Simulated in the NCEP Climate Forecast System Reanalysis. J. Climate 25, 6409–6425, doi: 10.1175/JCLI-D-11-00477.1.

(4) Ham, Y. & Kang, I., 2011: Improvement of seasonal forecasts with inclusion of tropical instability waves on initial conditions. Clim Dyn 36: 1277. doi:10.1007/s00382-010-0743-0

@CWCB_DNR: August 2016 #Drought Update

Colorado Drought Monitor August 16, 2016.
Colorado Drought Monitor August 16, 2016.

Click here to read the update from the Colorado Water Conservation Board (Taryn Finnessey/Tracy Kosloff):

July 2016, was the second month in a row during which the state experienced well below average precipitation. Statewide mountain precipitation was only 59 percent of average, the driest July since 2008. Temperatures were also above average. August to-date has brought near average precipitation and slightly cooler temperatures statewide. However, the Front Range corridor remains dry and warm. The forecast for the next week shows cooler temperatures and better chances for precipitation.

  • Statewide water year-to-date mountain precipitation as reported from NRCS is at 97 percent of normal as of August 16th.
  •  Reservoir storage statewide is 109 percent of normal. The Arkansas and the South Platte basins have the highest storage levels in the state at 115 percent of average; the Upper Rio Grande has the lowest storage levels at 89 percent. All other basins are above normal at 106 to 109 percent of average.
  • Front Range water providers all reported storage levels ranging from 83 to 124 percent of average, however continued warm and dry conditions have resulted in increased demands 10-20 percent greater than last year.
  • The Statewide Water Supply Index (SWSI) indicates that conditions are drier this month than last; however the majority of the state remains near average.
  • Agricultural producers are seeing high yields for both wheat and corn, and orchards are reporting good conditions as well.
  • #Drought news: I-25 corridor (D1), short-term dryness putting a strain on unirrigated vegetation, some tree leaves becoming crispy

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

    Summary

    A series of slow-moving or stationary cold fronts plus a westward wandering upper-air low along the Gulf Coast produced widespread moderate to heavy (more than 2 inches) rains in portions of the north-central Plains and upper Midwest, much of the Corn Belt, southern Great Plains, Ohio and lower Mississippi Valley, along the Gulf Coast, and the Northeast. Record flooding occurred in Louisiana where up to 2 feet of rain inundated the southern half of the state, requiring thousands of water rescues and drowning several people. Weekly amounts exceeding 8 inches also fell on southeastern Missouri, southern Illinois, north-central Indiana, and southwestern Lower Michigan. The southwest monsoon was also active, especially in New Mexico and southeastern Arizona where 1-2 inches of rain fell on several locations. Oppressive heat and humidity enveloped the northeastern quarter of the Nation, with weekly temperatures averaging more than 6 deg F above normal. Highs in the nineties were common, with some locations nearing triple-digits, but when combined with dew points in the seventies, apparent temperatures were unbearable to dangerous. In contrast, near to subnormal readings occurred across most of the western half of the U.S. and along the Gulf Coast. Most of Puerto Rico, Alaska, and Hawaii measured light to moderate rainfall, but not enough fell on the drought areas for any improvement…

    Southern Plains

    Abundant moisture from the southwest monsoon and the upper-air low interacted with a stationary cold front over the southern Plains, triggering numerous scattered showers and thunderstorms across southern and eastern sections of Texas and extreme southeastern Oklahoma. The rains, however, mostly missed the Texas Panhandle and the remainder of Oklahoma. With the scattered nature of the storms, totals varied widely, resulting in a spotted look to the remaining drought areas, although most changes were 1-category improvements (using 2-3 month tools). In contrast, subnormal rainfall resulted in some small degradation in the Texas Panhandle, extreme southern Texas, and in southern and northeastern Oklahoma. Field reports out of central and eastern Wagoner County (northeast OK) indicated worsening agricultural impacts due to less rainfall than surrounding counties, resulting in a D1 expansion and new D2 area…

    North-Central Plains and western Corn Belt

    A slow-moving cold front triggered widespread showers and thunderstorms across the north-central Plains, upper Midwest, and western Corn Belt. More than 2 inches of rain fell on most of the eastern Dakotas, central Minnesota, west-central Wisconsin, and southwestern and central Iowa, with locally up to 8 inches in parts of south-central Minnesota. This was the fourth out of the past 6 weeks with wet weather in Iowa. Accordingly, several 1-category improvements were made as the recent rains have eased or eliminated short-term dryness and drought. This included a good portion of South Dakota (D3 to D2 and D2 to D1 in the west; D1 to D0 in central sections; and D0 to nothing in northeastern and southeastern sections), northwestern Nebraska (D1 to D0 and D0 to nothing), Iowa (shrank D1 in the south, removed lots of D0), and northern Missouri (shrank D1 and D0). Most crop and pasture/range conditions were rated favorably with the exception of South Dakota. According to NASS/USDA, 25% of the SD pastures were rated poor to very poor, a reflection of drier conditions in the west…

    The Northwest and northern Rockies

    With July and August normally the two driest months of the year, not too many changes are typically expected during the late summer in the Pacific Northwest. This was the case this week as little or no precipitation occurred, and temperatures averaged slightly above normal. Farther east, unsettled weather (cool and showery) was observed in the northern Rockies and northern Montana, which was enough to prevent any deterioration but not enough for improvement. Except for the impact lines redrawn for better clarity of the impact types, no other changes were made…

    California and western Great Basin

    Since this is the normally dry and warm time of the year when no real changes are expected to occur, and since both temperature and precipitation was near normal this week, there were no changes made on the map…

    The Southwest (4-Corner States)

    Since the onset of the southwest monsoon in late July, scattered showers continued this week, with the greatest totals (1-3 inches) occurring in southeastern Arizona, southern and northeastern New Mexico, and southwestern Texas. With this week’s totals adding onto accumulated surpluses out to 3-, 6-, and even 12-months, some small improvements were made in southeastern Arizona (D2 to D1), southwestern Texas and southern New Mexico (D1 to D0), and D0 to nothing in southwestern and northeastern New Mexico and southwestern Texas (near El Paso). Enough rain has fallen over other areas since mid-July to keep conditions status-quo. An exception was in south-central Colorado where D0 was added as seasonal precipitation expectations have been below normal. In northern Colorado, a small area of D1 was added as short-term dryness was putting a strain on unirrigated vegetation, with some tree leaves becoming crispy. The impact lines were redrawn to reflect recent short-term wetness (SL changed to L in southern Arizona), and a SL buffer in eastern New Mexico (between the L to the west and S to the east)…

    Looking Ahead

    During the next 5 days (August 18-22), the Far West should stay seasonably dry. Meanwhile, the heaviest rains (1-4 inches) should fall on the southern Great Plains and upper Delta (TX-OK-AR), from southern Montana and northern Wyoming eastward to northern sections of Wisconsin and Michigan, on the southern Appalachians, and along the Carolinas coast. 5-day temperatures will be above-normal in the Far West and the Atlantic Coast States while subnormal readings are expected in the middle third of the Nation.

    During August 23-27, the odds favor above-median precipitation in the southern three-quarters of the Plains and most of Alaska, while sub-median rainfall is favored in Arizona, Pacific Northwest, and mid-Atlantic southward to the central Gulf Coast. Subnormal temperatures are likely in the southern two-thirds of the Rockies and Plains, the Tennessee and lower Ohio Valleys, and central Appalachians, while above-normal readings are favored in southern Alaska, the Pacific Northwest, and along the East Coast.

    From The Loveland Reporter-Herald:

    Federal officials said this week that Loveland is in the middle of a moderate drought this summer.

    In the U.S. Drought Monitor operated by the University of Nebraska-Lincoln, a narrow swath along Interstate 25 between Denver and the Wyoming border is considered to be in level D1 of drought. Last week’s report indicated the area was “abnormally dry,” and little precipitation has been reported in that time. The only other area of the state considered as dry was the Four Corners area, according to the report.

    By comparison, Southern California is in a prolonged level D4 drought, the highest level on the scale.

    According to the Community Collaborative Rain, Hail and Snow network spotters in Loveland, the city has seen less than half an inch of precipitation since the beginning of August, and only an inch of precipitation in July.

    National Weather Service forecasters said Thursday that the weekend will bring only a moderate chance of showers. Friday will have the strongest chance for showers in the city, at 40 percent, with the chance of precipitation decreasing into the weekend.

    The long-range forecast shows another slight chance of thunderstorms by the middle of next week, according to the agency.

    Meanwhile here’s the latest US seasonal drought outlook from the Climate Prediction Center:

    US Seasonal Drought Outlook August 18 through November 30, 2016 via the Climate Predication Center.
    US Seasonal Drought Outlook August 18 through November 30, 2016 via the Climate Predication Center.

    Climate: July breaks global temperature mark — again

    Summit County Citizens Voice

    Mideast heatwave set records

    fd All northern hemisphere land areas recorded above average temperatures in July 2016.

    Staff Report

    There was no letup to the global heatwave in July, according to the National Oceanic and Atmospheric Administration, which reported this week that the month ended up as the warmest ever recorded on planet Earth.

    Federal climate trackers said it was the 15th month in a row with above average temps, making it the longest such streak in NOAA’s 137 years of record keeping. The global temperature for July has been above average for 40 years in a row, since 1976. July was also the 379th consecutive month with temperatures above the 20th century average. The last month with temperatures below the 20th century average was December 1984, at 0.09 degrees Celsius below average.

    The combined average temperature over global land and ocean surfaces was 0.87 degrees Celsius above the 20th century…

    View original post 386 more words

    Uncompahgre Valley Water Forum Sept. 1 — The Montrose Press

    Uncompahgre River Valley looking south
    Uncompahgre River Valley looking south

    From The Montrose Press:

    John Stulp, special advisor to the Governor and director of the Inter Basin Compact Committee for the State of Colorado, will speak at the Uncompahgre Valley Water Forum Sept. 1.

    The event will be held at the Montrose County Fairgrounds in Friendship Hall 6:30-9 p.m. Stulp’s presentation will be focused on what the State Water Plan says about agricultural water.

    He will address the extent to which everyone is a recipient of the benefits that ag. water provides – not just the foods and fibers grown and raised that require water, but also important community amenities, like city parks, soccer fields and cemeteries which often depend on ag. water to keep grass growing and green.

    Shavano Conservation District is hosting the Uncompahgre Valley Water Forum to create a medium for landowners to be aware of ideas and views on local and state agricultural water.

    Other speakers at the Forum include Marc Catlin, who is the Water Development coordinator for Montrose County, sits on the Colorado River Water Conservation Board,and also on the Gunnison Basin Roundtable.

    Dick Wolfe, state engineer for the Colorado Division of Water Resources; Steve Anderson, manager of the Uncompahgre Valley Water Users Association; and MaryLou Smith from the Colorado Water Institute at Colorado State University, will also be on hand.

    Those planning to attend should RSVP by Aug. 29 to either Bert at 970-249-8407, ext. 115, or by email to bertha.earle@co.nacdnet.net.

    Water restrictions lifted in Fountain — The #Colorado Springs Gazette

    Widefield aquifer via the Colorado Water Institute.
    Widefield aquifer via the Colorado Water Institute.

    From The Colorado Springs Gazette (Rachel Riley):

    Stage 3 water restrictions, which were put in place in Fountain June 24 after perfluorinated compounds were found in area groundwater wells, were lifted Thursday.

    The restrictions, which limited irrigation to two days a week to avoid using well water and meet demands with surface water, were imposed after contamination was found in groundwater wells in Fountain, Widefield and Security at levels above Environmental Protection Agency recommendations…

    Stage 1 voluntary water restrictions remain in place in Fountain until Sept. 30, according to the utilities’ website.

    Under the voluntary restrictions, property owners and renters with street addresses ending in an even number are encouraged to use water outdoors on even-numbered calendared days, and vice-versa with residents with street addresses ending in an odd number. Property owners and renters area also encouraged to refrain from using water outdoors on the last day of each calendar month.