WASHINGTON—The El Niño effect is about to hit US weather, but it is not the primary cause of the ferocious storms that brought death and flooding to much of the South over the weekend, scientists said on Monday.
El Niño could, however, bring temporary relief to Midwesterners plagued by the violent weather.
It is predicted to cause a relatively dry winter from the Ohio Valley to the Mississippi River Valley, said Nicholas A. Bond, the Washington state climatologist and a senior researcher at the Joint Institute for the Study of Atmosphere and Ocean at the University of Washington.
“It is just sort of a fluke event,” Bond said of the weekend storms that brought tornadoes and violent storms at a time when people normally hope for a white Christmass. “Sometimes you can get these big troughs of lower pressure and ridges of higher pressure that set up in particular places and stay there, and end up steering the storms different than they usually are for this time of the year.
“There is just randomness in the weather that is always there,” he said. “And impossible, really, to predict with much lead time.”
Missouri State Climatologist Pat Guinan agreed, but said that even with the dry forecast, winter’s short days, cold temperatures and dormant plants are not conducive to evaporation.
“We are not going to dry out anytime soon regardless of what happens over the next few weeks,” he said.
While much-needed precipitation is forecast for the American Southwest from California to Texas, an El Niño effect about to kick in on North America will bring relief from saturated grounds elsewhere, according to the latest government forecast. “Seasonal outlooks indicate an increased likelihood of above-median precipitation across the southern tier of the US, and below-median precipitation over the northern tier of the US,” the National Oceanic and Atmospheric Administration said in a mid-December El Niño report.
“In terms of dryness, it is kind of the Ohio Valley extending…to the Mississippi, including the Saint Louis area,” Bond said.
El Niño describes a meteorological pattern spawned from unusually warm equatorial Pacific Ocean temperatures. Temperatures in that vast belt of water are unusually high already, and some scientists predict that the effect from them this winter is likely to be stronger than the last similar El Niño, which occurred in the winter of 1997-1998, and at least the third strongest since 1950.
This El Nino already has wreaked environmental and economic havoc in the Southern Hemisphere, disrupting the Australian cattle industry by parching pastures, hurting rice crops in Vietnam, hitting South Africa and parts of South America with drought, and sparking wildfires from Australia to Indonesia.
The effect on the United States so far has been milder weather in the northern half of the country, a typical El Niño trait. But other anticipated effects have not yet begin.
“When you kind of really dive down into the details, and look at what the situation has been like so far this winter, it isn’t a close match with what we have seen in the early winters of El Niños previously,” Bond said. “But what I should say also is that the computer models that we use to forecast the weather over the next week or two are showing a switch in the pattern to one that is very similar to what we have seen during previous El Niños.”
He said that “El Niño’s effects on the weather in the US tend to be…more prominent and reliable after the first of the year.”
Image credits: G.J. McCarthy /The Dallas Morning News via AP