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US El Nino Forecast: California, East to Bear Brunt of Impacts This Winter

By by Jillian MacMath, Staff Writer
October 22, 2015, 4:26:27 AM EDT

Since the first indication that a powerful El Niño was set to develop, there has been significant speculation about what impacts it would have within the United States.

El Niño is defined by above-normal sea surface temperatures in the eastern and central equatorial Pacific Ocean.

Occurring every two to five years, El Niño's most significant effects on North America occur during the wintertime.

However, the resulting weather varies depending on where the warm water temperatures are centered.

"Confidence continues to grow that this El Niño will be one of the strongest El Niños over the past 50 years," according to AccuWeather Meteorologist Brett Anderson.


Expected to mimic a similar pattern as the winter of 1997-1998, this year’s El Niño could mean big impacts to California and the eastern half of the United States.

The most likely, and most impactful, scenario during this winter is that California will get significant precipitation in the form of both rain and snow.

“California will be much more active weather-wise this winter than last winter,” AccuWeather Meteorologist Ben Noll said.

Copious amounts of rain from systems over the same area, a theme which occurs often during this type of weather pattern, can lead to problems for California.

Locals may be faced with flooding and mudslides, which could prove devastating for home and property owners. This will be especially problematic over recent burn scar areas, where rampant wildfires have charred millions of acres.

However, it won’t all be bad. California is expected to receive much-needed mountain snow, which is necessary to fill reservoirs in the spring.

According to AccuWeather Expert Long-Range Forecaster Paul Pastelok, the 2015-2016 season may yield triple the amount of snow than that which fell last year in the central and northern mountains.

This will allow locals to breathe a sigh of relief since April 1 measurements revealed snowpack across the Sierra Nevada was at its lowest level in 500 years.

“The current deficit is too large for this winter to end the drought,” according to Noll. “But this would certainly put a dent in it.”

On the opposite coast, the Northeast and Southeast will also help bear the brunt of El Niño’s effects.

Above-average storminess will greet cities such as Boston, New York City, Philadelphia, Newport and Raleigh, but the million dollar question remains: In what form will the precipitation fall?

The weather pattern threatens to send chilly air masses into the Eastern U.S., which could result in a corridor of snow from Texas up into the spine of the Appalachians.

However, the wild card will be whether the timing of the cold air matches up with the timing of the precipitation.

“If so, there could be a few big storms that blow our forecasts out of the water,” Noll said. “That’s a risk right there.”

2015-2016 US Winter Forecast
El Niño May Intensify Into Strongest in 50 Years Winter Weather Center

While it’s a precarious position for the mid-Atlantic and Northeast, there’s a good deal of certainty that the Great Lakes region will get less lake-effect snow than usual.

Climatologically, some of the driest years on record have occurred during El Niño years, according to Noll. Less lake-effect snow is typical, especially for the upper lakes.

Farther south, forecasters are concerned El Niño will lead to exceptional storminess.

“These big storms that will be barreling across the southern Plains and Southeast often drag fairly impressive cold fronts across the Gulf Coast,” Noll said.

“Once they head into Florida, you can be talking about explosive thunderstorms and very heavy rainfall.”

Additionally, El Niño may prolong the drought across the interior Northwest and promote milder days with less snow across much of the northern tier of the country.

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