Several inches of snow possible Thurs. night
Forecasters are weighing the chances we'll see some more snow showers tonight, along with what should be mostly rain showers. But there's a more significant chance that the next few inches of snow we see will arrive late Thursday into Friday.
AccuWeather.com sees a pattern here, and predicts more storms like these - and maybe a bigger one - right into February.
Tonight's disturbance in The Force will come with a little system due to swing throught the region early Wednesday morning. Forecasters and their computer models aren't sure whether much or
any of it will fall as snow. Temperatures will hang right near the freezing mark. But the snow and ice cover could drop temperatures in some locations low enough to allow some flakes to form.
In any event, there's not much moisture with the system, NWS forecasters say. So they're not terribly concerned about accumulations. "If there were to be any snow accumulation, it would be spotty along the Pa. border," the discussion from Sterling advises.
Eric the Red urges caution when you step out Wednesday morning: "Be alert ... for pockets of freezing rain ... Most urban areas will be rain, but outside the beltways could be dicey."
More intertesting is the next system, which arrives late Thursday after a sunny break Wednesday afternoon and Thursday daytime. The NWS is giving it a 50 percent chance of snow showers
Thursday night, slipping to 40 percent Friday morning.
The weather service describes the storm as carrying more moisture than tonight's, but dropping down from the Great Lakes and intensifying off the coast to our east Friday.
"Low-level thickness [of cold air] supports wintry precipitation further south than the mid-week upper wave," Sterling says. "Chances for snow a bit better across the area, but again only light [precipitation] expected, and of a scattered and intermittent nature."
Eric the Red sees it this way: "...[A] swath of snow north of the storm center and a mixed mess along and south of the storm track. This would put much of northern VA and central/northern MD in line for several inches of snow. The [model] consensus is 2-4"... with some heavier (the WRF/NAM looks more like 4-8", and the Canadian is heavier too), while the GFS is a bit lighter (1-3").
"I kinda like the 2-4" forecast meself ... Friday morning rush hour looks like fun."
Much depends on the storm tracks. Eric lays down three scenarios: "1) Storm is faster and weaker, and produces a quick-hitting trace to an inch... if that. 2) The storm tracks farther north, and gives us sleet and freezing rain instead of snow. 3) The storm deepens more rapidly than expected, which would push totals up."
Foot's Forecast advises: "This potential second round of winter weather would understandably wreak havoc with school schedules in areas just affected by today's event. School administrators faced with the task of rescheduling mid-terms are advised to continue monitoring statements by their local NWS forecast office as well as our regional facebook forecast centers for the latest developments on this possible "round two."
(SUN PHOTO: Jeffrey Bill)








Comments
Frank,
What is the difference betweek sleet and fronzen rain.
Thanks.
FR: The difference is the temperature profile between the altitude where the precipitation forms, and the surface. Sleet occurs when warm air aloft produces raindrops, which then fall through a thick layer of much colder air, freezing into little ice pellets on the way down. Sleet can accumulate like snow. Frozen rain occurs when the cold layer at the surface is thinner. The rain forms in warm air aloft, then falls intact to the surface. where it freezes on contact, putting a thin layer of ice on streets, sidewalks, handrails, cars etc.
Posted by: Linda Tanton | January 18, 2011 3:35 PM
I've heard sleet described as Mother Nature dropping bb's out of the sky (they can sting, but don't hurt like hail). Freezing rain, I've heard, can be compared to Mother Nature painting everything in ice, a thin layer at a time.
Posted by: Mike | January 19, 2011 4:13 AM