Winter in VS 2012/2013 - Meer sneeuw en storm op komst

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Op zondag 7 oktober 2012 19:21 schreef Klonk het volgende:
Toch grappig dat het zuiden van Alaska een vergelijkbaar klimaat heeft als Nederland, zo zonder erbij na te denken denk je bij Alaska aan kou

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Elusive El Niņo challenges NOAA’s 2012 U.S. Winter Outlook
October 18, 2012

The western half of the continental U.S. and central and northern Alaska could be in for a warmer-than-average winter, while most of Florida might be colder-than-normal December through February, according to NOAA’s annual Winter Outlook announced today from the agency’s new Center for Weather and Climate Prediction in College Park, Md.

Forecasters with NOAA’s Climate Prediction Center say a wavering El Niņo, expected to have developed by now, makes this year’s winter outlook less certain than previous years.

“This is one of the most challenging outlooks we’ve produced in recent years because El Niņo decided not to show up as expected,” said Mike Halpert, deputy director of NOAA’s Climate Prediction Center. “In fact, it stalled out last month, leaving neutral conditions in place in the tropical Pacific.”

When El Niņo is present, warmer ocean water in the equatorial Pacific shifts the patterns of tropical rainfall that in turn influence the strength and position of the jetstream and storms over the Pacific Ocean and United States. This climate pattern gives seasonal forecasters confidence in how the U.S. winter will unfold. An El Niņo watch remains in effect because there’s still a window for it to emerge.

Other climate factors can influence winter weather across the country. Some of these factors, such as the North Atlantic Oscillation, a prominent climate pattern, are difficult to predict more than one to two weeks in advance. The NAO adds uncertainty to the winter outlook in the Northeast and Mid-Atlantic portions of the country.

Areas ravaged by extreme drought over the past year are unlikely to see much relief from drought conditions this winter.

Warmer-than-average temperatures in much of Texas, northward through the Central and Northern Plains and westward across the Southwest, the Northern Rockies, and eastern Washington, Oregon and California, as well as the northern two-thirds of Alaska.
Cooler-than-average temperatures in Hawaii and in most of Florida, excluding the panhandle.
Drier-than-average conditions in Hawaii, the Pacific Northwest and Northern California, including Idaho, western Montana, and portions of Wyoming, Utah and most of Nevada.
Drier-than-average conditions in the upper Midwest, including Minnesota, Wisconsin, Iowa and northern Missouri and eastern parts of North and South Dakota, Nebraska, Kansas, and western Illinois.
Wetter-than-average conditions across the Gulf Coast states from the northern half of Florida to eastern Texas.
The rest of the country falls into the “equal chance” category, meaning these areas have an equal chance for above-, near-, or below-normal temperatures and/or precipitation.

This seasonal outlook does not project where and when snowstorms may hit or provide total seasonal snowfall accumulations. Snow forecasts are dependent upon the strength and track of winter storms, which are generally not predictable more than a week in advance.

NOAA's National Weather Service is the primary source of weather data, forecasts and warnings for the United States and its territories. NOAA’s National Weather Service operates the most advanced weather and flood warning and forecast system in the world, helping to protect lives and property and enhance the national economy. Working with partners, NOAA’s National Weather Service is building a Weather-Ready Nation to support community resilience in the face of increasing vulnerability to extreme weather. Visit us online at weather.gov and on Facebook.

NOAA’s mission is to understand and predict changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Visit us at www.noaa.gov and join us on Facebook, Twitter and our other social media channels.

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A series of storms into early next week will bring tremendous high country snow and the risk of avalanches to the West.
Yards of snow will fall on the northern Sierra Nevada, and feet of snow will accumulate in the Cascades.
Snow levels will vary during the siege of storms and will dip to pass levels at times, especially over the northern Cascades.
At elevations above 7,500 feet in the northern Sierra Nevada, the storms are likely to bring between 6 and 10 feet of snow with blizzard conditions at times due to winds topping 100 mph. Similar conditions are in store for Mount Shasta.
High winds, even below snow levels, could cause some high-profile vehicles to roll over.

Conditions may get much worse than this over some of the passes in the Cascades this weekend.

Through the weekend and into early next week, from 2 to 4 feet of snow is forecast to fall over the high country in the Cascades of Washington and Oregon, as well as the Bitterroots of Idaho and Montana.
Wintry Travel
For a brief time, snow will fall down to the high spots on I-80 at Donner Pass, where a half a foot to a foot of wet snow can fall through Friday. Over the weekend, snow levels will rise above pass level in the northern Sierra Nevada.

Farther north, rounds of snow will end up being more of a problem for travelers.
Initially, through Friday, accumulating snow will be above most passes in the Cascades of Washington and Oregon. Snow levels during this period will generally be above 4,000 feet. A mixture of rain and snow can occur over I-90 through Snoqualmie Pass through Friday.

However, over the weekend, snow levels will lower as the air turns a bit colder. This will bring accumulating snow to many passes Sunday into next week. By Monday, snow levels may lower to near 2,500 feet.
The storms and their snow through much of next week will avoid the Arizona Rim Country, the Wasatch and central and southern Rockies.
in the northern Sierra Nevada, snow levels will rise significantly Sunday, before falling back early next week. That could bring a rapid meltdown of the snow at rather high elevations for a time and add to the risk of flooding and other problems.
Avalanche Danger
The series of storms with their high country snow will raise the risk of avalanches.
Feet and yards of snow accumulating in rapid fashion, combined with locally high winds and fluctuating temperatures, will make the slopes very unstable.

While avalanches are more common in the late winter and spring, they can occur in situations like this during the late autumn and early winter.
There is a possibility of significant snow slides especially over the weekend into next week.
By then the weight of the snow will be tremendous and any surge of warmth next week can cause the snow on the slopes to give way.

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A potent winter storm will impact the region for the rest of this weekend. Moderate to heavy snow is expected tonight across eastern South Dakota and western Minnesota. This will be followed by lighter snow, but increasing northwest winds by early Sunday morning. With the increasing northwest winds, wide-side blizzard conditions are expected for locations along the North Dakota, South Dakota border.

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OKLAHOMA CITY - The Oklahoma Highway Patrol and local police departments responded to several Christmas morning car accidents, including a major crash involving 20 vehicles on westbound Interstate 40 near Interstate 35.
Check on road conditions in Oklahoma City

Freezing rain turned highways and roads across central Oklahoma into slick messes. Around 4:30 a.m., cars began losing control on a westbound I-40 overpass at I-35. The weather created black ice on the overpass and drivers were taken by surprise.

Three semi trucks and 17 cars crashed into each other. State troopers shut down westbound I-40, and shuttled drivers to a nearby hotel while they investigated the multi-car crash and tried to clear away the wreckage.

It's not known when the highway will reopen.