Last Winter’s Snow Doesn’t Erase The West’s Long-Term Drought — Or A Shifting Climate ~ Colo Public Radio

By The Associated Press

August 15, 2019
Colorado River-Climate ChangeRichard Vogel/AP
This March 26, 2019 photo shows the water level of the Colorado River, as seen from the Hoover Dam, Ariz.

Snow swamped mountains across the U.S. West last winter, leaving enough to thrill skiers into the summer, swelling rivers and streams when it melted, and largely making wildfire restrictions unnecessary. But the wet weather can be misleading.

Climate change means the region is still getting drier and hotter.

“It only demonstrates the wide swings we have to manage going forward,” James Eklund, former director of the Upper Colorado River Commission, an interstate agency that ensures river water is doled out properly, said earlier this year. “You can put an ice cube — even an excellent ice cube — in a cup of hot coffee, but eventually it’s going to disappear.”

For the seven states relying on the Colorado River, which carries melted snow from the Rocky Mountains to the Gulf of California, that means a future with increasingly less water for farms and cities.

Climate scientists say it’s hard to predict how much less. The river supplies 40 million people in Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming as well as a $5-billion-a-year agricultural industry.

The U.S. Bureau of Reclamation on Thursday will release its projections for next year’s supply from Lake Mead, a key reservoir that feeds Colorado River water to Nevada, Arizona, California and Mexico.

After a wet winter, the agency isn’t expected to require any states to take cuts to their share of water.

But that doesn’t mean conditions are improving long term. Arizona, Nevada and Mexico could give up some water voluntarily in 2020 under a drought contingency plan approved by the seven states earlier this year.

Here is a look at the Colorado River amid climate change:

Colorado River Flow

Much of the water in the Colorado River and its tributaries originates as snow.

As temperatures rise and demand grows, the water supply declines. Even if more snow and rain fell, it wouldn’t necessarily all end up in the river. Plants will suck up more water, and it will evaporate quicker.

Brad Udall, a water and climate research scientist at Colorado State University, said the river’s flow could decrease even further to 20 percent by 2050 and 35 percent by 2100.

“On any given day, it’s hotter, we have more days for a growing season to occur, we have a thirstier atmosphere,” he said. “When you put all those things together, you lose flow in the river.”

The Changing Climate

Climate change doesn’t mean the American West will be hot and dry all the time. Extreme swings in weather are expected as part of a changing climate — something Udall has called “weather whiplash.”

The Southwest got a reprieve this year with average and above-average snowfallfollowing a year that sent many states into extreme drought. Nearly empty reservoirs quickly rose, including Lake Mead and Lake Powell — the largest manmade reservoirs in the country that hold Colorado River water.

The lakes still are far below capacity, steadily declining since 2000 with a bigger spike after winter 2011.

A wet year interrupting years of dryness isn’t uncommon.

“We’re very thankful for this gain in wet hydrology and storage in the reservoirs that happened this year, but we know we can lose it just as fast,” said Carly Jerla with the U.S. Bureau of Reclamation.

About That Drought

Many states declared an end to short-term drought this year, based on the U.S. Drought Monitor, which looks at land conditions.

The map is produced by the National Drought Migration Center, the U.S. Department of Agriculture and the National Oceanic and Atmospheric Administration.

But not all agencies use the same indicators for drought.

The U.S. Bureau of Reclamation uses Lake Mead on the Nevada-Arizona border and Lake Powell on the Arizona-Utah border. The reservoirs were nearly full in 1999 before the agency declared a drought the following year that hasn’t let up. As of Monday, Lake Powell was 57 percent full and Lake Mead was 39 percent full.

Jerla says the bureau won’t say the drought is over until those reservoirs fill completely, which won’t happen without consecutive years of wet weather.

Protecting The Colorado

The seven states that rely on the Colorado River signed a plan earlier this year to protect the waterway from climate change and keep Lake Mead and Lake Powell fuller.

The drought contingency plan is meant to keep the reservoirs from dropping so low that they cannot deliver water or produce hydropower amid prolonged drought and climate change.

Nevada, California and Arizona voluntarily would give up water when Lake Mead reaches certain levels, as would Mexico, which also gets a portion of water from the river. The deal expires in 2026, and the states will begin negotiating new guidelines next year.

AccuWeather misleads on global warming and heat waves, a throwback to its past climate denial ~ The Washington Post

People cool off in New York’s Flushing Meadows Corona Park on July 21 during a heat wave. (Johannes Eisele/AFP/Getty Images)

August 9 at 3:16 PM

A week after a punishing heat wave torched the eastern two-thirds of the country, setting numerous records, AccuWeather chief executive Joel Myers cast doubt on the scientific finding that heat waves in the United States and elsewhere are worsening because of climate change. This point of view, at odds with peer-reviewed research, is reminiscent of the contrarian position AccuWeather took on the climate change issue in the 1990s, which historical documents recently obtained by The Washington Post shine light on.

Both then and now, AccuWeather has landed on the wrong side of the science.

Myers’s essay “Throwing cold water on extreme heat hype,” published online Wednesday, attempts to debunk the scientific finding that heat waves in the United States are becoming more severe, but he cherry-picks data and shows an incomplete understanding of the drivers of temperature change.

“[A]lthough average temperatures have been higher in recent years, there is no evidence so far that extreme heat waves are becoming more common because of climate change, especially when you consider how many heat waves occurred historically compared to recent history,” Myers writes.

In saying this, he ignores the U.S. government’s National Climate Assessment, published in 2018 and signed off on by 13 federal agencies, which flat out states — with very high confidence — that the frequency of heat waves has increased since the mid-1960s.

Myers relies mostly on historical data from the 1930s to make his case that heat waves haven’t gotten worse. “Here is a fact rarely, if ever, mentioned,” he writes, “26 of the 50 states set their all-time high temperature recordsduring the 1930s that still stand (some have since been tied).”

He concludes: “Given these numbers … it cannot be said that either the frequency or magnitude of heat waves is more common today.”

But there are problems with this argument that have been addressed in the scientific literature and independent analyses.

The heat waves of the 1930s were exacerbated by land mismanagement tied to the Dust Bowl. A combination of springtime drought and farming practices left fields bare of vegetation, which allowed summer temperatures to skyrocket. In other words, the extreme heat of the 1930s is a reflection of specific circumstances in that decade and does not invalidate a link between today’s heat waves and climate change.

Zeke Hausfather, a climate scientist for Berkeley Earth, which specializes in temperature data, points out that although the heat waves in the 1930s may have had higher daytime temperatures, present-day nighttime temperatures are much higher. This is an expected outcome of climate change as the atmosphere responds to increased concentrations of greenhouse gases.

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1983, the year Glen Canyon dam nearly failed ~ Arizona Central

Tim Lane and I were still sweeping storm boards on Red Mountain Pass, June of 1983 for the Insitute of Arctic and Alpine Research San Juan Project.  It was a big winter but the heavy snows (above normal density, almost 15% or twice the average) didn’t really begin until February and continued much like  this year (2019) into late spring (June).  It was truly an amazing experience on a daily basis wondering if the storms were ever going to end.  All of this snow finally melted in the north San Juan mountains and flowed into the Colorado river basin and eventually to Glen Canyon dam to overflow its top..  Kevin Fedarko wrote ‘The Emerald Mile‘ that contains a fine chapter on the winter of 1983 that created this near disaster.  

rŌbert

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The first public sign that something was up came in the form of a short story in the Arizona Daily Sun in Flagstaff. It was only six paragraphs, but it appeared on the front page above the fold:

“Glen Canyon Dam Water Releases to Increase,” the headline read.

It was June 2, 1983, and the story didn’t even begin to hint at the drama that was about to unfold.

“PAGE — Early snowmelt due to higher than normal temperatures is forcing the earlier than normal release of water from Glen Canyon Dam here, authorities said Thursday.”

Almost every word was an understatement.

“The water releases were to begin at noon today and (Glen Canyon recreation area superintendent John) Lancaster said they could go as high as 38,000 cubic feet per second,” the story said.

The releases were likely to continue for the next month and campers along the Colorado River were advised to seek higher ground and secure their boats.

Two weeks earlier, embattled Interior Secretary James Watt had paid a visit to Glen Canyon, the nation’s second highest concrete arch dam, to celebrate the 20th anniversary of its completion.

Soaring 710 feet and anchored in Navajo sandstone, the dam was conceived in desert thirst, born into controversy, and swaddled in argument.

The debate over Glen Canyon Dam was not just emblematic of the new American West, but part of its fabric.

On one side, Native Americans and environmentalists decried the loss of a pristine canyon filled with sacred and historic sites and an ecosystem as beautiful and enigmatic as the Grand Canyon. On the other, developers and chambers of commerce argued for the need to protect downstream users from flooding and to provide the water and power needed to turn small desert cities into the sprawling metropolises they’ve become today.

By June 1983 the debate had long been settled in favor of growth, but there was a new question looming: Could people safely control nature? It was a question fueled by nature’s unpredictable wrath as 8 trillion gallons of water in one of the nation’s largest reservoirs bore down on 10 million tons of concrete in one of the nation’s largest engineering marvels.

It was uncharted territory for both people and nature, and the stakes were high.

Within a month of the AP news story, water in Lake Powell would come within inches of topping the dam’s massive spillway gates as engineers frantically tried everything they could think of, rigging 4-by-8 sheets of plywood to extend the top of the gates and releasing more than half a million gallons per second into the Colorado River.

de3beb03-8163-4a46-984a-e32f43900759-Dam-Flashboards_7-7-1983_copy.jpgLake Powell water levels rose steadily during June and July 1983, forcing the Bureau of Reclamation to use plywood barriers to keep the lake from spilling over the closed gates on Glen Canyon Dam.
(Photo: Photo courtesy Bureau of Reclamation)

 

Before it was over, the force of the water releases would gouge house-size holes in the dam’s crippled concrete spillways. The white water would tinge red from the bedrock sandstone, and ominous rumbling sounds would be heard as boulders the size of cars belched from one of the spillways into the river.

The more water the engineers released, the more damage they did. But they had no choice.

“We were sitting on a pretty good catastrophe waiting to happen,” said Art Grosch, an electrician who worked at the dam and ran electrical cable into the mangled spillways.

“That lake (Powell) is 190 miles long and has something like 2,300 miles of shoreline,” he said. “And it was rising a foot a day.”

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Monsoon update from Joe Ramey, Mountain Weather Master and former meterologist with the NWS

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Remember me? Climate is nearly always more interesting in the rear view mirror. It has been a very interesting year so far with the startling cool wet winter and spring that completely erased drought from Colorado. Now we have this overdue monsoon that has dried all those early-season grasses into kindling. Monsoon seasons too are best resolved in the rear view mirror. Perhaps we will say the third week in July was the beginning.
At the NWS offices here in GJ and down in southern NM, we had an adage: the monsoonal moisture won’t get pulled up into the Rockies until mountain snow melt is complete. The idea is, it is difficult to create a Four-Corners thermal Low while the sun’s regional energy is still being used to transition ice to water and vapor. And since Low pressure sucks, its hard to suck in the subtropical moisture without it.
So I was surprised in late June when the CPC outlook showed above normal precipitation chances for western Colorado while the high-mountain snowpack was still impressively deep and the 10-day forecast models still looked dry. Since I had no finger on the pulse I thought those climate guys must be onto something interesting. Well we are still waiting for something interesting.
The new one and three month outlook is no longer excited about the Southwest monsoon.

 

But there is some reason for hope. The vast majority of the mountain snowpack is in the rivers and the wee rest will follow shortly. The weather pattern turns more favorable: the subtropical High has been suppressed to our south but begins to rebound northward this weekend as a trough comes in off the Pacific. So this will produce a S-SW flow. There is an inverted trough that looks to work up from Mexico next week perhaps up into western Colorado by mid-week. This could bring deep moisture with it. Of course that will render my swamp cooler useless here in GJ so I will venture out in the early morning only. Lets hope it happens! Water is life.
Hope your summers are going well.
Joe Ramey

Odds Favor Wetter than Normal July as Monsoon Season Looms ~ NWS, Grand Junction

Odds Favor Wetter than Normal July as Monsoon Season Looms

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The Climate Prediction Center recently released their latest monthly temperature and precipitation outlooks for July 2018. Odds are favoring wetter than normal conditions developing across much of the southwestern United States, especially in the Four Corners area. The wet conditions look to continue through September as the CPC’s three month outlook (including the months of July, August and September) shows odds favoring above normal precipitation. As far as temperatures are concerned, odds favor warmer than normal temperatures across Utah and into far western Colorado for July with above normal temperatures favored across the entire western United States through September.

July 2018 Temperature and Precipitation Outlooks

July 2018 Climate Outlook

Three Month Temperature and Precipitation Outlooks

(Including the months of July, August and September)

Three Month Climate Outlook

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What is the Monsoon?

The North American Monsoon Season typically begins towards the end of July and continues through early September. It is associated with a long duration weather pattern shift as the subtropical ridge of high pressure amplifies and moves to our east. This results in a shift in upper level winds with the flow turning to the south, allowing for moisture to be pulled northward from the Pacific Ocean and the Gulf of Mexico.

Monsoon Schematic

Dallas is swallowed by a massive ‘rain bomb’

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Heavy rains and storms left parts of Louisiana underwater due to severe flooding June 6.

June 9, 2017

I feel like we need a sound effect for this one. Would it sound like a whoosh? Maybe a crashing wave?

It’s not every day you see a textbook microburst like this one caught on camera, but Toddy Jack managed to get this insane photo on Sunday afternoon. At the time, Dallas was getting drenched with heavy rain as this nearly stationary storm sat over the area. Then it finally and literallyunloaded all of its precipitation in a giant “rain bomb” — right over downtown.

A microburst is a sudden but powerful area of sinking air, associated with the downdraft area of a thunderstorm. While microbursts are typically small, and 2.5 miles in diameter or smaller, they can do incredible damage. Microbursts can have wind speeds in excess of 100 mph, and have been known to do so much harm that the destruction left behind can be mistaken for tornado damage.

A microburst occurs when a thunderstorm simply can no longer “hold” its precipitation. Think of it as being like a brown paper grocery bag. When the bottom of the bag can no longer support the weight of the groceries within, it breaks and all your apples, oranges, etc. fall and spread out all over the floor. Microbursts behave the same way.

When an updraft is strong, it can hold and suspend large amounts of rain droplets as well as hail within the cloud. When the updraft weakens, as is especially typical with a vertically stacked summertime storm, it can no longer hold that rain and hail within. Eventually, the updraft collapses, and all the precipitation crashes to the ground and spreads out in all directions.

While microbursts can do extreme damage to buildings and landscapes such as forests and croplands, they are especially dangerous for aircraft. It is impossible to predict when and exactly where a microburst may occur during a thunderstorm, which makes planes that are either taking off and especially landing (times when the planes are closest to the ground) susceptible if caught in one of these powerful downdrafts. Unfortunately, several fatal airline crashes in history can be attributed to microbursts.

There are actually two types of microbursts: wet and dry. Wet microbursts are most common in the Southeast during the summer months, while dry microbursts are more common over the West. The storm over Dallas on Monday was a wet microburst, as seen by the dark rain curtain spilling out of the cloud.

Microbursts are also known for the visual feature called “rain foots” (think Elf Shoes) that occur when the rain and/or dust hits the ground, then curls back upward as it spreads out horizontally on each side.