Understanding the U.S. Drought and Heatwave: Five Good Visuals

As the drought drags on, these graphics and interactives explain what’s happening

1. “Drought’s Footprint”The New York Times

In June, more than half of the U.S. was experiencing moderate to extreme drought. How does that compare to other years? The Times’ graphic lays it out.

2. “Dried Out: Confronting the Texas Drought” — NPR, KUT and KUHF

The drought began in Texas in October of last year. Watch it grow over time, and explore a timeline that explains the root causes of the drought and how communities are responding.

3. “Flash Drought in U.S. Explained in 14 Seconds”Climate Central

Watch an animation showing the spread of the drought, from Texas and Georgia in March, to most of the Midwest and West by June.

4. Drought Impact Reporter — The National Drought Mitigation Center

This is “the nation’s first comprehensive database of drought impacts.” Submit reports of how the drought affects you, and search for drought impacts by state, whether they’re to agriculture, industry, public health or wildlife.

5. “Historic heat wave in hindsight: Hottest on record in Washington D.C., hotter than 1930”Washington Post

From the Post’s weather blog, a local, numbers-heavy analysis of the heatwave that hit Washington. With stats like “Longest period at or above 100: 7 hours on July 7 (tie with July 6, 2010 and July 21, 1930),” it’s like a Guinness Book of World Records for D.C.’s summer, and holds my usually California-focused attention.

Drought Has Ties to La Niña, with Global Warming Assist

La Niña has been linked to historical droughts, including the Dust Bowl


A cow feeds in a drought-damaged pasture as temperatures climb near 100 degrees on July 17, 2012 near Princeton, Indiana.

Driven by a combination of natural climate variability, manmade global warming, and plain old bad luck, drought conditions are so widespread in the U.S. that it’s possible to take a cross-country flight from Washington, D.C. to San Francisco — a distance of approximately 2,400 miles — without once overflying an unaffected area. With about 81 percent of the lower 48 states experiencing at least abnormally dry conditions, and 63 percent mired in moderate-to-exceptional drought, it’s becoming harder and harder to find an oasis. And the dog days of August are yet to come.

The National Oceanic and Atmospheric Administration (NOAA) already ranks this drought as one of the worst on record, comparable to the drought events of the 1950s. The last time there were such widespread drought conditions in the corn-growing region of the country was in 1988, and that drought cost at least $40 billion.

Given this summer’s punishing 1-2 punch of dry weather and heat, this drought is also being compared to the Dust Bowl era of the 1930s. Continue reading

Dry Weather Boosts Odds of Extreme Heat

A new study finds that drought in one month increases the likelihood of heat in the next


As soil dries, more of the sun’s energy goes into heating the air directly, rather than evaporating moisture from the ground.

Droughts such as the one currently gripping a majority of the U.S. may dramatically increase the odds of extremely hot days, a new study found. The study, published in Proceedings of the National Academy of Sciences, explores a dynamic that is playing out right now across the country, particularly in the Great Plains, where the severe drought is priming the atmosphere in favor of an above-average number of extremely hot days.

This occurs because of feedbacks between the ground and the air: as the soil and vegetation dry, more of the sun’s energy is able to go into heating the air directly, rather than going into evaporating moisture from plants and the soil.

With drought conditions intensifying during mid-summer, the study suggests that the U.S. may be in for particularly brutal Dog Days of August. Continue reading

This Winter Looking Like Fourth Warmest for Lower 48

Could be second-driest winter on record for California, Pacific Northwest

Rain comes late to Northern California: A March storm front hovers over San Pablo Bay, north of San Francisco.

Last week’s State of the Climate report issued by the National Oceanic and Atmospheric Administration found that this winter is stacking up as the warmest since 2000 and the fourth warmest on record in the contiguous United States.

According to NOAA, 47 of 48 states experienced above-average temperatures in the period between December and February, with the greatest increases seen in the Northeast and Midwest.

Only New Mexico saw below-average temperatures. Continue reading

Snow Survey May Portend a Dry 2013

Skimpy Sierra snowpack may take a while to show up in water supplies

snow Tahoe Sierra California water

After a record dry December, there's finally snow on the ground near Soda Springs, at Lake Tahoe.

This morning’s snow survey (PDF) didn’t turn up any big surprises. As remote sensors foreshadowed, water content in the Sierra snowpack is 37% of normal for this time of year, and less than a quarter of the average for April, which is when the snowpack is usually at its peak before it begins melting and filling up California’s reservoirs.

What’s worrisome about that, according to Jeanine Jones, Interstate Resources Manager at the Department of Water Resources, is that about half of California’s annual precipitation typically falls between December and February, months that are mostly already behind us. “So where we are this year is: November was dry, December was close to record dry, January was maybe half of average,” Jones told me. “And currently the forecast for the first  ten days or so of February is essentially dry.” Continue reading

Drought Is in the Eye of the Beholder

Are we in one? Water officials say the answer is “Yes and No”

How do you define a "drought?"

As state surveyors trudge into the mountains this week for the season’s second official survey of the Sierra snowpack, the auspices aren’t good. Remote sensors currently show that statewide, water content is averaging just 38% of the average for this date, and less than a quarter of what water managers would hope to see on April first — just two months away.

Consequently, the “D-word” is being nervously bandied about. Are we in a drought?

The state’s newly revamped Current Water Conditions website takes on the question with a definitive “Yes and no.” Drought status, it says “can be very different depending on your location.” Continue reading

CSI Colorado: Sudden Aspen Decline Post-Mortem

Droughts kill trees — but until now scientists didn’t know the root of the problem

Aspens live at high elevations in the Western United States, including in California's White Mountains and Sierra Nevada.

Throughout the West, aspens are quaking for good reason.

About 17% of the aspen in the Colorado Rockies have died in the last decade. That’s about one in every six trees. The widespread die-off, called sudden aspen decline, began after a severe drought and heat wave. So people studying the trees knew that’s what triggered the deaths, but they didn’t know what exactly killed the trees.

William Anderegg, a grad student at Stanford, with help from a team of scientists there and at the University of Utah, has zeroed in on the culprit, and describes the work in a paper published this week. There were two working theories: failures in photosynthesis, which would mean less food for the tree; or damage to the roots, which would mean less water. Anderegg found it was the roots.

Continue reading

Take Your Pick: Wetter, Drier, and Hotter for California

New science forecasts include everything except moderation

Scientists say there's a little bit of everything on the horizon for California -- except maybe funds to study it.

Two days before Governor Jerry Brown hosts his own conference on “Extreme Climate Risks and California’s Future,” scientists and a smattering of state and local officials spent a rainy Tuesday at Scripps Institution of Oceanography in La Jolla, talking about just that.

It began with calls to keep the funding for statewide climate research. Sacramento legislators may be looking at cutting money to the Public Interest Energy Research (PIER) program in particular, and California Energy Commission vice chair James Boyd told the crowd “all is not well.”  He said that research funding is “under assault again” with the weak economy used to question the focus on climate at a time when predictions are becoming more severe. Continue reading

Two-Year Drop in California Carbon Emissions

PG&E substation near San Jose. The drop in emissions applied to both power generated in California and imported from neighboring states. (Photo: Craig Miller)

If you’re ready for some good news on the climate front: California’s carbon emissions from power generation dropped in 2009 and 2010.

That’s according to a new analysis from Thomson Reuters’ Point Carbon that looked at power generated here in California, as well as electricity imported from out of state.

According to the report (available by subscription only), emissions were down 12% over the study period. Part of the drop, not surprisingly, was due the global recession and the state’s slowed economy in 2009. But the study found that even when the economy started growing again, emissions continued to decline.

Sound mysterious? Not really, according to study co-author Ashley Lawson. Continue reading

Forget this Winter: Western Snowpack Shrinking

By Alyson Kenward

A new study finds large losses of springtime snow cover in the West in recent years, raising concerns about water supplies.

Spring snowpack in the West is an essential water resource, particularly in Southwestern states that are prone to summer drought, like California, Nevada, Arizona and New Mexico. (Credit: Wolfgang Staudt on Flickr)

This spring, from the Pacific Northwest and Sierra Nevada, to the Northern Rockies, western mountain ranges were more than just snow-capped – they were buried in the white stuff. In fact, many locations still have more spring snowpack than has been seen in decades.

Head south across the 40th parallel, however, and things are dramatically different. While there is still above average snow throughout the Sierra, a relatively snow-less winter and spring has left much of the Southwest in a drought that has fostered record wildfires. Already local officials are worried there won’t be enough water to get through the summer months ahead. Continue reading