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Climate: Is the Southwest ‘stuck’ in a drought pattern?

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NOAA’s winter outlook offers little relief for Arizona, New Mexico

By Bob Berwyn

FRISCO — Drought conditions may persist across the southwestern U.S. this winter and may redevelop across the Southeast, according to the seasonal outlook from NOAA’s Climate Prediction Center.

“Even though we don’t have La Niña, the atmosphere across the Pacific seems to be stuck in a La Niña mode … It’s been quite surprising to us, how persistent the pattern is,” said Mike Halpert, acting director of the Climate Prediction Center.

Parts of the Southwest, especially New Mexico, have been experiencing one of the driest periods on record, and Halpert said there is “decent agreement” in the CPC’s models on the climate signal that has resulted in the persistent trend. Continue reading

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Environment: ‘Extreme’ dust-on-snow events can speed runoff in Colorado River Basin by six weeks

2013 brought record levels of dust to Colorado’s mountains

More frequent desert dust storms dropping pollution on the Rocky Mountain snowpack is one of the climate change impacts affect the high country.

More frequent desert dust storms dropping pollution on the Rocky Mountain snowpack is one of the climate change impacts affecting the Colorado high country.

By Bob Berwyn

FRISCO — Dust storms that darken the Rocky Mountain snowpack and speed snowmelt are becoming more extreme, according to new research. Particularly heavy dust-on-snow events can speed the melt-out of the snowpack by a full six weeks, all other factors being equal, said Jeffrey Deems, a researcher with the Western Water Assessment and the National Snow and Ice Data Center.

“In 2006 we were impressed at how much dust there was. Then 2009 turned up, and 2010, and 2013 was the dustiest year we’ve recorded in the San Juans,” Deems said, explaining that the latest study, put together by researchers with NOAA’s Cooperative Institute for Research in Environmental Sciences was aimed at updating previous work with data from those heavy dust years.

Last spring, on April 8, a single 16-hour dust storm dropped more dust on the San Juans than the annual totals in any previous winter since scientists started taking detailed measurements, said Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton, which tracks the dust-on-snow events via a network of observation sites. Continue reading

Climate: Can forests heal themselves from drought?

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California’s redwood forests recycle ocean fog to create their own microclimate. bberwyn photo.

Amazon rainforest may be more resilient than previously believed

By Summit Voice

FRISCO — As one of the Earth’s big lungs, the fate of the Amazon rainforest in the face of global warming is a critical climate question. New research suggests that, with strong conservation measures in place, the rainforest may be more able to cope with dry conditions than projected by other studies.

Many climate models over-predict the water stress plants feel during the dry season because they don’t take into account the moisture that the forest itself can recycle in times of drought. In this study, published in the Journal of Climate, the researchers removed unrealistic water stress from their model and found that the moisture that is recycled by the forest is sufficient to reduce the intensity of drought conditions. Continue reading

Climate study shows that deforestation of the Amazon could dry out the western United States

Shifts in precipitation patterns would have big consequences for agriculture, forests and municipal water supplies

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Research suggests that deforestation will likely produce a weather cycle over the Amazon consisting of abnormally dry air in the sun-scorched northern Amazon around the equator weighted by wetter air in the cooler south (left). The Princeton-led researchers found that the Amazon pattern would be subject to meandering high-altitude winds known as Rossby waves that move east or west across the planet (center). The Rossby waves would move the dry end of the Amazon pattern directly over the western United States from December to February, while the pattern’s rainy portion would be over the Pacific Ocean south of Mexico (right). Image courtesy Princeton University.

By Summit Voice

FRISCO — Continued deforestation in the Amazon region could have significant impacts on the weather in North America, according to Princeton researchers, who used fine-grained climate models to simulate how precipitation patterns could shift in the future.

Their findings suggest that  total deforestation of the Amazon may significantly reduce rain and snowfall in the western United States — specifically, 20 percent less rain for the coastal Northwest and a 50 percent reduction in the Sierra Nevada snowpack, a crucial source of water for cities and farms in California.

“The big point is that Amazon deforestation will not only affect the Amazon — it will not be contained. It will hit the atmosphere and the atmosphere will carry those responses,” said lead author David Medvigy, an assistant professor of geosciences at Princeton. Continue reading

Climate: 4th-driest year on record at Lake Powell

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Lake Powell: Going, going … gone?

High flow experiment planned for early November to restore aquatic and riparian Colorado River ecosystems downstream of Glen Canyon Dam

By Summit Voice

FRISCO — Even with some bonus inflow in September, the past water year Oct 1, 2012 – Sept. 30, 2013) ended up as the fourth-driest on record for the Colorado River Basin as measured at Lake Powell — the key reservoir on the river that helps balance supply and demand between the upper and lower basins.

Overall water storage in the Colorado River Basin in the last 14 years has ranged from a high of 94 percent of capacity in 2000 to the present low of 50 percent at the start of the 2014 water year.

Continue reading

Global warming: Water shortages loom for millions

‘This is not about ducks and daisies, but the very basis of life’

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By Summit Voice

FRISCO — As many as 500 million people could face water shortages in the coming decades, as a warming climate affects global water supplies.

“We managed to quantify a number of crucial impacts of climate change on the global land area,” said Dieter Gerten, of the Potsdam Institute for Climate Impact Research.

Mean global warming of 2 degrees Celsius, the target set by the international community, is projected to expose an additional 8 percent of humankind to new or increased water scarcity. If global temperatures increase by 3.5 degrees Celsius, shortages would affect  11 percent of the world population. Continue reading

Climate: From drought to deluge

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Climate experts outline weather extremes across the U.S.

By Bob Berwyn

After years of persistent drought across big swaths of contiguous 48 states, the weather picture changed dramatically in 2012. Instead of dealing with parched ground, farmers in the Southeast weren’t able to harvest crops this summer because of standing water in the fields.

Mold and fungal diseases were reported across the region, particularly on crops such as corn, tomatoes and peanuts. The excess moisture has degraded the quality and flavor of many crops, including watermelons, tobacco, and peaches. Flooded soil  has hampered the growth of cotton and corn, with damage from excess moisture expected to cost billions, The National Climatic Data Center reported this week in its July update. Continue reading

Hearing shines spotlight on Colorado River woes

The dried up delta where the Colorado River reaches the Sea of Cortez

The dried up delta where the Colorado River reaches the Sea of Cortez is symbolic of the challenges facing the river.More information at this NASA Earth Observatory website.

‘Make every drop count’

By Summit Voice

FRISCO — The Colorado River took center stage in Congress for a few hours this week, as the Senate Subcommittee on Water and Power focused on a recent Colorado River study that predicts a growing gap between what the demand for water and what the river can deliver.

The hearing was chaired Sen. Mark Udall, a Colorado Democrat, who knows first-hand what is at stake, from the headwaters in the mighty Rockies down to the Gulf of California. Business as usual just won’t cut it, Udall said, advocating for a short-term focus on conservation, innovation and better management of supply. A video of the hearing, as well as the written testimony of the witnesses, is online here. Continue reading

June brings near-record dry conditions to Summit County

Temps run well above average for the month

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Summer time in Summit County. Bob Berwyn photo.

By Bob Berwyn

FRISCO — June, the second-driest month in Summit County, ended up especially dry this year, with only 0.26 inches of precipitation at the official National Weather Service site in Breckenridge, and even less — 0.19 inches at the Dillon station.

Averages for the two sites are 1.37 inches in Breckenridge and 1.14 inches at Dillon, where there was measurable precipitation on two days, June 18 and June 29.

The sparse total in Breckenridge made it the fourth-driest (tied with 2006) on record, dating back more than 100 years, said weather observer Rick Bly. The driest June ever (0.06 inches) was in 1980, during another notable Colorado dry spell, followed by June 1891 (0.10 inches) and June 2002 (0.24 inches). Continue reading

Climate: Drought expanding again in Colorado

Odds favor above-average temps the next few months

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June brought dry and warm conditions to Colorado.

By Summit Voice

FRISCO — After a short-lived burst of late spring moisture, much of Colorado is veering back toward drought conditions, with soil moisture declining in many parts of the state.

Even the north-central mountains, which saw above-average precipitation in late April and May, are drying out again, and parts of Summit and Grand counties are once again designated as experience “moderate” drought conditions, according to the June 18 drought monitor. The far southwestern corner of the state slipped back into “extreme” drought conditions.

And while Denver Water recently eased its watering restrictions, the drought monitor shows that moderate drought conditions have returned to the Colorado Front Range, including Denver, Boulder, Longmont, Loveland, Fort Collins and Greeley. Continue reading

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