There's not much more certainty today about the prospects for a snowstorm on Christmas Day. It does look like the system is likely to slow down, but the computer models are still divided over whether it will steer south and east of the mid-Atlantic, or crank up off the Virginia Capes for a real jingle bell-ringer.
Here's what UMBC's Prof. Jeff Halverson is saying this morning:
"The shorter-term models have started to take the storm farther south and out to sea, and slowed down the timing, which would mean a reprieve on Christmas Day.
"But the European model (ECMWF) bucks the tide, developing a massive, rapidly deepening storm that stalls just off the Delmarva Christmas Day night into Sunday-Monday, the type of storm that would bring the Mid Atlantic and New England to its knees, and a contender to be a historic high wind and heavy snow event.
"It seems that HPC is buying into this solution, at least for now...this is getting to be a very interesting late holiday forecast...stay tuned!"
For their part, the forecasters at the National Weather Service's Baltimore-Washington Forecast Office in Sterling have bought in to the idea of this storm slowing down. They expect we won't see anything until Saturday night at the earliest. Their seven-day forecast calls for sunny weather through Friday, with a mostly cloudy day on Christmas Day.
They give the snow a 50 percent chance on Saturday night, followed by more of the same Sunday. Daytime highs Sunday would be near the freezing mark.
In their morning discussion Wednesday, the Sterling folks see the storm center moving out of Texas early Saturday, then east across the Deep South at about the same time that another storm system moves out of the Great Lakes toward the mid-Atlantic.
"The southern jet should induce cyclogenesis across the northern Gulf, or along the southeast continental U.S. Saturday night. But future evolution and interaction with the northern system [is] highly uncertain at the moment."
"The GFS [computer model] keeps [the] two systems from phasing [combining and strengthening] ...and weak low pressure moves quickly northeast, well offshore Sunday.
"ECMWF [another model] keep low pressure moving slower, and strengthens it rapidly ... Latter solution would provide for [more moisture] , much better chance for measurable snow across mid-Atlantic Sunday, possibly into Monday."
"Due to unusually high uncertainty and potential for significant snow over holiday weekend and busy travel period, monitor forecast closely."
AccuWeather.com is hanging on to the possibility of a snowy Christmas for the mid-Atlantic:
"The storm may not head completely out to sea. Computer models have been consistently turning the storm northward Saturday night into Monday. As a result, there is a chance of snow spreading up the I-95 corridor in the Northeast.
"The cold, dry roadblock that shunted snow to the east over much of the I-95 Northeast this past weekend is still present. However, it does not look to be as strong and could allow accumulating snow to run up the coast late in the Christmas weekend."
Ain't this fun?
(SUN PHOTO: Jed Kirschbaum, December 2009)