You know that burst of frigid air and snow we had last week?

That was a sneak peek of December.

The first month of winter likely will be cold and may bring us a significant snowfall, Millersville University meteorologist Eric Horst said today, in his annual outlook for the upcoming winter.

"It's a signal that we've locked into a colder pattern," he said, "a pattern that I'm fairly certain continues into December. It will be cooler than normal with some early-season snow, perhaps a significant snow between now and Christmas."

As for the rest of winter, Horst said the signals are not quite so clear. He expects the early part of the season to be the coldest, with February and early March maybe a bit milder.

"It's perhaps more of a front-loaded winter," he said.

The signals for the upcoming season come from several global indicators.

One of the most reliable indicators is the temperature of the surface of the sea in the equatorial Pacific Ocean.

Warmer temperatures are an El Nino phase, which gives us colder winters here. Cooler temperatures are a La Nina phase, which gives us milder winters here.

La Nina was setting the stage for last winter, which was a real dud in terms of snowfall. Only 13 inches fell, half of the usual 26 inches we get in a winter. Temperatures also were several degrees above normal.

This year, the equatorial Pacific water temperature is at its average, meaning it's neither warmer nor colder than usual.

"That's kind of an anything-goes winter," Horst said.

Those kind of winters can offer a full gamut of weather conditions: snowy or dry, freezing or balmy.

Fortunately for all of us who want to know whether we need to gas up the snow blower, there is another weather indicator meteorologists can examine.

That indicator is barometric pressure cycles over the north Atlantic Ocean.

These pressure cycles are more short term, lasting several months, and indicate warmer or colder conditions.

Right now, we are in a phase that began in late summer and is closely correlated to colder conditions in the Northeast.

"Right now," Horst said, "things are set up for a good start to winter .... which means the door is open to an early snowfall."

Decembers generally are not snowy months here — 4.5 inches of snow is the average.

But the 2000s have brought some significant December snowfalls: 8-inch snowfalls occurred in both 2002 and 2003 and a 6-inch snowfall occurred in 2005.

Beyond that, the pressure cycle may be due to change and milder weather may move in for the last half of winter.

And what are our chances for a monster storm?

Snowfalls of a foot or more happen three or four times a decade. Snowstorms of 20 inches or more happen once a decade.

In the past 10 years, we have had two snowfalls in the range of 12 inches: 12 inches fell Jan. 25, 2000, and 14 inches fell Feb. 12, 2006. We had a 24-inch snowfall Feb. 16, 2003.

Horst won't predict whether we'll get a big one this winter.

But he said, "In relationship to last winter, it's highly likely this winter brings more snow and cold."


Staff writer Cindy Stauffer can be reached at cstauffer@LNPnews.com or 481-6024.