Wintry mix in travel forecast for D.C. area
Thursday, December 24, 2009
People waiting to make a last-minute dash out of town Christmas morning may face the region's two most cursed weather words: wintry mix.
Thousands of Washington area drivers had relatively smooth going as they made their escape Wednesday, but the weather window for comfortable winter travel is expected to slam closed on Christmas morning.
After more than 24 hours of subfreezing temperatures, a rain-sleet mix could fall on frozen pavement and turn to ice faster than salt trucks can get to it.
"We're hopeful it falls as rain. Wouldn't that be great?" said Karyn LeBlanc, spokeswoman for the District Department of Transportation. "But we're encouraging people who are going to visit family or friends to go the night before."
The Christmas morning forecast calls for ground-level temperatures several degrees below freezing, but warmer temperatures at higher elevations mean that precipitation will emerge from the clouds as rain.
"That's a recipe for ice," said Jason Samenow, chief meteorologist for the Capital Weather Gang. "It's looking like an icy mix at least until noon, and as you go west into the Shenandoah Valley it may last into the afternoon."
Samenow said the approaching storm was large enough to drop an inch of rain, which could combine with melting snow to cause flooding in some places.
With road crews exhausted by days of 12-hour shifts, highway officials were eyeing that forecast and trying to clear snow from drains.
"Our concern would be that with all the snow still out there, an inch of rain would cause flooding," said Charlie Gischlar of the Maryland State Highway Administration. "We've got people out there right now clearing drainage areas so the rain and melting snow have some place to go."
LeBlanc said a coating of ice on unshoveled sidewalks would make them doubly treacherous, and she urged property owners to clear sidewalks before the big snow becomes the big freeze.
Although traffic was slow in spots on Interstate 95 north and south of the Capital Beltway on Wednesday, the flow suggested that many of the 2.2 million drivers expected to depart for the holidays had left already or were waiting until Thursday.
But if most Washington drivers were having a relatively easy time three days after the big snow, people leaving by plane and those headed to New York and New England by train appeared to have more to worry about.