Luebehusen plotted what experts call a “flash drought.” While not fully understood, these quick-developing droughts might be another signature of climate change. Experts say a flash drought often begins as a pin-sized swelter in one county, then expands like an amoeba across the landscape. The droughts are often accompanied by erratic precipitation over sharply defined geographic areas. The downpours can be extraordinarily intense, just as climate change is transforming routine rain events into mega-storms.
Oct 3 2019, E&E News
Flash drought: ‘Really wet to really dry, really fast’ | Daniel Cusick As a member of the Agriculture Department team that compiles the U.S. Drought Monitor, Luebehusen created what looked like an omelet on a map of the United States. Yellow and brown swirls covered much of Texas and swaths of the Southeast, with splotches of red mixed in. “Here you have a divergent signal where many of these folks have had near-historic wetness and drought all within 60 to 90 days,” he said, describing a kind of weather whiplash. “People went from really wet to really dry, really fast.” Luebehusen plotted what experts call a “flash drought.” While not fully understood, these quick-developing droughts might be another signature of climate change. Experts say a flash drought often begins as a pin-sized swelter in one county, then expands like an amoeba across the landscape. The droughts are often accompanied by erratic precipitation over sharply defined geographic areas.
The downpours can be extraordinarily intense, just as climate change is transforming routine rain events into mega-storms. On Luebehusen’s drought map for Sept. 24, two small areas popped out like red ripe tomatoes in Shelby County, Ala., and Dallas County, Texas. Both were experiencing “extreme drought,” one category shy of the highest rung on the drought severity scale. In Shelby County, a fast-growing suburb of Birmingham, more than 200,000 people experienced near-record temperatures and extreme dryness, what scientists call D3 drought. Less than 30 miles away, Birmingham was at D0, or “abnormally dry,” but not in drought. The same thing happened in Texas, where moisture and temperature gauges in Dallas County measured dangerously dry conditions, while seven surrounding counties were not in a drought. […]
Svoboda said droughts didn’t always behave this way. The term “flash drought” first appeared in a 2001 research paper by Svoboda and was not widely used until after 2012, when a fast-forming drought enveloped the Great Plains, he said. And yet some conditions that make a “flash drought” are not new. In the Gulf South, dry conditions can form and dissipate quickly, especially in late summer and early fall. The same is true of thunderstorms, which can form over tightly drawn areas and miss nearby areas — sometimes within a mile — altogether. What’s changing is the variability and intensity of these precipitation and temperature conditions, said John Nielsen-Gammon, the Texas state climatologist and professor of atmospheric science at Texas A&M University. Dallas County, for example, has two primary monitoring stations, at Dallas Love Field Airport and Dallas/Fort Worth International Airport about 15 miles away.
In Houston, a rash of storms tests the limits of coping with climate change
The New York Times | Christopher Flavelle ]Houston’s challenge reflects the dilemma facing cities everywhere: As the climate changes, disasters aren’t just becoming more severe, but also more frequent. So even as the amount of damage increases, governments and residents have less time to repair before the next storm hits. And structural changes that might reduce cities’ exposure require years or decades to complete. […] Shortly after Harvey, the county and city each increased the so-called freeboard requirement for homes, which dictates how high a building’s ground floor must be above the height of an expected 100-year flood. But those rules affect only new or rebuilt homes, and so will take decades to ripple through to most houses. And large-scale infrastructure projects, such as deepening drainage canals or building pits to store rainwater, often take years to complete. In August 2018, Harris County voters approved a $2.5 billion bond to fund such projects. But most are still in the design phase. Then environmental permits must be obtained, as well as the acquisition of property rights. Only then can construction begin. “You run into environmental permitting timelines that we can’t speed up,” said Ms. Hidalgo. “Even though we have 254 projects or so slated, you can’t do them all at the same time.” The rush of disasters has strained the Harris County Flood Control District, which had finished repairing just one-quarter of the flood infrastructure damaged by Harvey when Imelda hit. And now it has to manage a 10-fold increase in spending. […] It’s not just construction projects that move slowly. Officials have sought to buy the homes of some people flooded after Harvey, with the intention of tearing those homes down so they can’t flood again. But the average buyout funded by the Federal Emergency Management Agency nationwide takes more than five years, according to data compiled by the Natural Resources Defense Council. In the meantime, many homeowners give up and instead repair or rebuild in place — setting themselves up for future pain when the next storm strikes.
Exceptional heat wave topples October records across much of the U.S.
The Washington Post | Matthew Cappucci and Andrew Freedman As of 2:08 p.m., the District of Columbia had broken its all-time monthly high temperature record with a temperature of 98 degrees, easily beating the old record of 96 degrees set on Oct. 5, 1941. The high in Newark hit 94 — 24 degrees above normal — while the temperature in New York’s Central Park reached 92 degrees for the first 90-degree or higher reading in October since 1941. It’s no different elsewhere up and down the Mid-Atlantic. Baltimore reached 98 degrees Wednesday, which easily became its hottest October day on record. Wilmington, Delaware hit 96 degrees so far — both a record for the date and the month. Previously, they had never climbed above 91 in October. It’s a similar story in Atlantic City, New Jersey, where the previous October record high was 90 degrees. It has climbed to 95. Philadelphia, meanwhile, broke into the 90s as well. By Thursday, however, the city will see temperatures fall dramatically, with highs stuck in the lower to mid-60s as a cold front sweeps in with northeasterly winds and occasional rain. To the south, Greer, South Carolina shattered its former monthly record high by 5 degrees. Fulton County Airport in Atlanta did it by 4 degrees, breaking a record they set just last year; that record had broken one from 2016. […] It’s been a remarkable summer and early fall for extreme heat in Atlanta and the rest of the Southeast. The city hit 90 degrees an astonishing 23 times in September — surprising when you consider the average September high is between 78 and 86 degrees. September as a whole wound up a hair under nine degrees above normal. […] Overall, increasing global temperatures are upping the odds and severity of heat waves around the world. Along the boundary between the hot conditions in the East and cooler weather in the West, heavy rain and severe weather was firing up across the Great Plains.
Blackouts are on the rise. So Austin is making a ‘microgrid’
E&E News | John Fialka The Department of Energy and the nation’s utilities are exploring ways to make cities more resilient in the face of mounting and costly blackouts from severe storms and heat waves that are increasing with climate change. They will use of a variety of relatively new features appearing in urban grids, including large storage batteries, a rising number of rooftop solar installations, and new computer-controlled programs and switches. They will also ask for help from homeowners. Some utilities are already promoting devices such as two-way controls on air conditioners, thermostats and even electric water heaters to reduce consumer power demand on super-warm days. The most ambitious effort would give control to a local utility to make a rapid grid reconfiguration at the onset of a blackout. It will attempt to collect and distribute enough renewable energy to support an “island,” or smaller area of the grid that can quickly repower hospitals, police and fire stations, and other emergency centers. The stage for this experiment is called the Mueller neighborhood in the east-central part of Austin, Texas, a large modern housing development started in 1999 on the runways of what was the city’s former municipal airport. Mueller has many pieces of the puzzle that might be needed, including a proliferation of new homes with rooftop solar arrays and a recently installed large battery storage system that Austin’s municipal utility, Austin Energy, helped acquire with a federal grant. Austin’s first goal was to use the neighborhood and the big battery to help expand its reliance on renewable energy to 65% by 2027. Austin Energy has already started using the battery, installed on the edge of the Mueller neighborhood, to collect enough solar power to help it meet increased electricity demand during spates of 100 degree days. “We’re also using it to do energy arbitrage,” said Cameron Freberg, a strategist for the utility. The battery collects and delivers solar power for use during the day, when electricity rates are high. The system recharges at night with cheap wind power from the grid, so it’s ready for the next day’s struggle to keep up with air conditioning demands. […] The arrival of a powerful storm, such as Hurricane Harvey, which shut down more than a dozen power plants in 2017 and left 100,000 Texans without power, gives relatively little time to prepare. Planners hope that forming an island, or what some call a “microgrid,” will give them more tools to restore power. “Every year we’re installing more and more solar, so we need to understand how these things interact with each other,” Hinson said. The Mueller neighborhood “provides a very nice test bed to do that.”
