Warm in the West, but not as dry as you might have thought

update: Jeff Lukas, in the comments, notes that I missed something important, which is the distinction between statewide averages and the east-west precip divide. As he correctly points out, that statewide blob of wet-looking Colorado hides the fact that it’s been extremely wet to the east, and relatively dry west of the continental divide. Here’s …

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Lake Powell spring runoff forecast this year now less than half of average

At the risk of nickel-and-diming you with bad forecast news, today’s Bureau of Reclamation mid-month report is bad forecast news. April-July flow into Lake Powell is now forecast to be just 3.4 million acre feet, 47 percent of average (pdf). That’s down from 3.75 maf (52 percent) just two weeks ago. Runoff for the full …

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Precipitation-runoff relationships in sustained drought

This paper is measuring stuff in Australia, but seems to mimic the dropoff in runoff we’re seeing on the Rio Grande and other western U.S. rivers compared to the precipitation deficits we’re experiencing: Annual rainfall and runoff records from south-eastern Australia are used to examine whether interdecadal climate variability induces changes in hydrological behavior. We test …

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Southwest monsoon!

Sorry, that was a clickbait headline. Let me walk it back: Odds shifted slightly toward a wetter Southwest monsoon this summer!   The usual forecast explainer: this shifts the odds from the climatological one-in-three-years-is-wet statistical binning to a 33-40 percent chance of wet in the light green area, upwards of 40 percent in the dark …

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What do we mean by drought?

Darren Ficklin at Indiana University has a new paper exploring trends in drought in the United States which notes that the trends are not universal: [F]our regions of increasing (upper Midwest, Louisiana, southeastern United States (US), and western US) and decreasing (New England, Pacific Northwest, upper Great Plains, and Ohio River Valley) drought trends…. But …

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On the Rio Grande drought, not exactly optimism, but not pessimism either

Michael Wines in Monday’s New York Times: The perils of drought are on ample display along the Rio Grande, where a rising thirst has tested farmers, fueled environmental battles over vanishing fish and pushed a water-rights dispute between Texas and New Mexico to the Supreme Court. But you can also see glimmers of hope. Albuquerque, …

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