Storm edges into Sunday, track still uncertain
The most definite thing that can be said about the prospects for a Christmas snowstorm in Baltimore may be that the storm mostly likely won't get to the East Coast by Christmas. But nobody is sure yet whether Central Maryland should prepare for a near miss, or a serious day-after-Christmas winter storm.
The best news is that, if you're traveling in the region on Friday or Saturday, the chances are you'll be able to make the trip without worrying about getting stranded in a ditch, or at the in-laws' house.
Forecasters say the storm - still coming ashore in California on Wednesday afternoon - looks like it will be moving slowly enough to put off any snowfall in the mid-Atlantic states until Sunday and Monday.
What happens then remains a frustrating meteorological cliffhanger - all the more so because so many millions of Americans will be traveling this weekend into the path of this cross-country storm.
"To give you a number, an exact snow total, wouldn't be a great forecast because there is such uncertainty with the storm," said Jared Klein, a National Weather Service forecaster in Sterling, Va. "It's a very complex pattern" that is still coming together.
The complex computer models that forecasters use to predict the evolution of such storms days ahead of the actual events simply have not been able to reach agreement on this one. Some have been predicting a track that would take the bad weather off the southeast coast of the United States and out to sea. Others bring it off the Virginia Capes by Sunday, tracking up the coast with a major snowstorm for the mid-Atlantic.
"There are some models that are showing a light dusting, and there are some systems showing heavy snowfall ... six inches or more," Klein said.
It's not like last year, he said. "With the December and February storms, five or six days out we saw this coming. We didn't give amounts this far out, but there was a lot of agreement on a big storm."
That should begin to change as the Pacific element of the storm gets ashore in California, and more surface observations and analyses can be made. "Usually, when you start getting three days before the event, you start getting higher confidence," Klein said.
One issue on which there was increasing agreement Wednesday, in addition to the later arrival, was on the storm's intensity. "There is increasing confidence it is going to be a strong storm," Klein said. But "it may be out to sea, too."
As the hours went by Wednesday, the models, and forecasters, could do no better than offer a choice between two possible scenarios.
The afternoon online forecast discussion from the weather service in Sterling, said, "The first scenario is that low pressure intensifies as it tracks along the coastline, producing a significant snowstorm across the area. The second scenario is that the low remains far enough off the coast for little or no snowfall across our area."
"Latest guidance [Wednesday] has trended a bit towards the first scenario, but [computer model] guidance still remains divergent in the overall solution," forecasters said.
The forecasters at AccuWeather.com, in State College, Pa., took a similar, two-choices (map at left) approach: "The first is the storm will quickly strengthen, tracking northward along the coast and spreading heavy, accumulating snow through the I-95 mid-Atlantic and New England. Snow could extend back to the Appalachians with this track."
"The second," they continued, "is the storm will drop accumulating snow on part of Georgia and the Carolinas, but then head out to sea. However, this track could still allow the storm to hook back into New England with heavy, windswept snow."
Other meteorologists have weighed in with their own ideas about how this storm will behave four or five days out. Eric the Red, a professional forecaster from Baltimore who contributes his predictions anonymously to the Maryland Weather Blog, said, "The trend is ominous ... There is going to be a whale of a storm moving up the coast Sunday into Monday. Its final final track means everything ... but I'm starting to get that sinking feeling about Monday."
Foot's Forecast, a forecasting web site manned by high school and college students who did well with last winter's storms, was saying this on Wednesday:
"Abundant surface and upper level cold air in place across the eastern U.S., combined with the expected influx of Pacific moisture may increase the possibility that energy from [the] northern jet stream phases with an already active subtropical jet. This scenario would produce a significant to major winter storm along the U.S. East Coast."