Talk of a Storm Next Week; It's Complicated

By Alex Sosnowski, Expert Senior Meteorologist

November 23,2012; 9:06PM,EST

There are indications a storm will affect all or part of the eastern third of the nation next week. However, multiple scenarios are on the table.
AccuWeather.com meteorologists have been cautiously monitoring global weather patterns, including a parent storm over the northern Pacific Ocean. That storm will take a route into the Northwest and across the Rockies over the weekend.
What happens from there remains a question for the extent of clouds and precipitation over the Midwest, South and Northeast Tuesday into Wednesday. The storm could split into two parts or merely dip to the south.
One scenario has two very weak storm systems, one running across the south with rain showers and one well to the north along the U.S./Canada border with mostly lake-effect snow and flurries. In between, over most of the populous, zip.

A second scenario is for a single storm to be produced (or remain stronger than the other) that travels from the lower Mississippi Valley toward the coastal Northeast. Such a path would bring a period of rain along the way with the possibility of thunderstorms to its south and perhaps a band of snow or wintry mix on its northern fringe.

The exact track of this storm and its strength will determine how heavy the rain, snow and thunderstorms are, and where the battle lines for the precipitation are drawn.
In any case, a powerful storm system with excessive precipitation does not appear likely this time. The pattern favors nothing worse than an average storm next week. However, an average storm for this time of the year can still bring some minor travel disruptions due to rain and snow and perhaps spotty strong thunderstorms in the South.
With a weaker storm idea, the cold air would be less likely to leave easily from the Upper Midwest to New England and much of the mid-Atlantic.
Updates on the storm, be it a period of rain or snow or just patchy clouds, will follow on AccuWeather.com into next week.
Otherwise, despite the seemingly warm feel for November, temperatures have averaged significantly below normal for the month.
According to Expert Senior Meteorologist Bob Larson, "This is largely due to clear skies in recent days and weeks, resulting in large temperature swings from day to night."

The sun felt nice and warm during the day, but the long, clear nights have allowed temperatures to plummet, overwhelming the daytime positive departures.
"Normally, there is a great deal of cloud cover acting as a blanket or insulation from big extremes," Larson said.
With light winds, there has been no lasting flow of cold air over the Great Lakes prior to this weekend. The Great Lakes are a major source of cloud cover in the Midwest and Northeast this time of the year.

The chill this weekend and beyond will add to the below-normal temperatures in some areas and extend the departures farther north through the end of the month.

Thumbnail image by photos.com.