The National Oceanic and Atmospheric Administration (NOAA) predicts this winter will be a dry one for much of the South and the Southwest, suggesting that droughts already impacting those regions are likely to intensify, reports Henry Fountain for the New York Times.
The parts of the Southwest and Intermountain West currently experiencing drought comprise nearly half of the continental United States, reports Jeremy Jacobs of E&E News. And NOAA’s new winter outlook has those drought conditions, the most widespread since 2013, expected to spread west.
"The big story is likely to be drought," Mike Halpert, the deputy director of NOAA's Climate Prediction Center, tells E&E News. "The winter forecast doesn't bode well. Drought is likely to develop in central and Southern California."
NOAA’s precipitation forecast predicts a dry winter for the entire southerly portion of the U.S., stretching from North Carolina to Southern California, reports Seth Borenstein for the Associated Press (AP). A wet winter was only predicted for the most northern states: “Oregon and Washington to Michigan and dipping down to Illinois, Indiana, Ohio and other parts of the Ohio Valley,” writes Borenstein for the AP. The remaining horizontal band of states across the U.S. are predicted to experience normal levels of rain and snow.
Temperature-wise, the majority of the U.S. will be warmer than usual this winter, per the AP, with only Washington, northern Idaho, Montana, the Dakotas and northwestern Minnesota predicted to be colder.
According to the Times, NOAA also says 2020 has a roughly two-thirds chance of unseating 2016 as the warmest year on record for the entire planet, and is “very likely” to be in the top three.
For the Southwest, the forecast, and the drought it’s predicted to exacerbate, is a continuation of the parched conditions that have plagued the region for much of the last two decades, per the Times.
In a paper published in April in the journal Science, researchers suggested that the Southwest is in the grips of an emerging megadrought, of a piece with dry spells that have stretched for as long as 40 years. The most recent megadroughts were in the late 1500s and in the ninth century. “This appears to be just the beginning of a more extreme trend toward megadrought as global warming continues,” the researchers wrote.
In fire-ravaged California, the dry winter will do little to dampen an already historically destructive fire season that traditionally extends into the colder months.
NOAA’s predictions for parched soils are largely driven by the La Niña conditions that appeared in the eastern tropical Pacific Ocean in August and are expected to stick around through winter, according to the Times. A La Niña is declared when water temperatures on the surface of the central Pacific are cooler than normal, which occurs on average every two to seven years.
Cooler surface waters at sea impact atmospheric circulation, which can alter weather around the world and typically results in warm, dry weather in the American South and cool, wet weather in the North, according to the AP.
Right now, NOAA sea surface temperatures suggest a moderate to strong La Niña is coming, but, speaking with the Times, Halpert emphasizes that NOAA’s winter predictions are just that, and could fail to materialize.