Foot's Forecast | Weather Intelligence

WILL A SHORT WEEK BE EVEN SHORTER?

TUE 2/19 10:00 PM. For those of you in the school system, whether students, parents or teachers, the answer is MOST LIKELY YES. Since we are approaching the onset of this 2-3 day event, I have condensed the main ideas down to just a basic overview. If you need more detail, scroll down below this post for the analysis from this past weekend.

THE WEEK AHEAD: A clipper arrives Wednesday afternoon in the Baltimore Metro area, but most likely late enough in the day to affect evening traffic more than closing schools early. This system may produce accumulations similar to that of the Dec 5 storm which caused a 2 hour delay the next day in many school districts. There could be 1-2" across the region by early Thursday morning, prompting another round of delays. The second event will be a series of weak Low pressure systems moving toward the Mid-Atlantic from Thursday night through Saturday morning. Given that snow, sleet and freezing rain are projected starting Thursday night, it is becoming increasingly likely this will interfere with the school schedule on Friday.

THE BREAKDOWN:

WHEN? First round arrives Wednesday afternoon in the Baltimore Metro region and may produce up to 2" before departing late evening. Slick roads may cause schools delays Thursday morning. Second round moves in Thursday night and continuing through Saturday morning, total period accumulation for the DC-Baltimore Metro region by Friday morning could near 4" which includes 1/2" or more of sleet/freezing rain.

WORST PART? Well that's hard to say because it ALL looks bad for commuters. Friday morning is likely to be the most difficult travel period of the week.

HOW LONG? Majority of precipitation will exit the region by Saturday afternoon, and may even change to rain Friday afternoon before it does.

WHAT ABOUT SCHOOL? I suspect delays Thursday morning, and many schools closed Friday across the region from Virginia to Maryland to southeastern PA and New Jersey.

QUESTIONS ABOUT THE STORM SITUATION POSED BY READERS

1. Why isn't this going to be a coastal storm and give a lot of precip to the mid Atlantic?

Highly unlikely the current setup will result in a single coastal storm like Jan 22, 1987 or Dec 4-5, 2002 to name a few. Too much upper level energy spread over a large area is going to prevent any one Low pressure system from wrapping up all that energy and turning into a classic Nor'easter. The high is not projected to be in the best spot for that anyway. The best comparison could very well end up being the Valentine's Day Massacre of 2007, where some areas of the Mid-Atlantic got near equal amounts of snow AND sleet/freezing rain. There will be a lot of precip, but along I-95 and north/west of the cities, it is likely to be a kitchen sink storm.. snow over to ice and maybe even back over to snow before ending Saturday. Adding the variable of ice always cuts down on snow accumulations, but precip there will be for sure.

2. In the 03 storm the temps were becomming marginal for snow or ice and it snowed. Could it be anything like 03 and a huge suprise to everyone?

I just came across an intriguing map posted on the Eastern US Weather Forums, and I'll post it here for you to see shortly. It's all about the high. In that situation the high was clearly sliding over the Great Lakes and into southeast Canada. Not so this time, though the models are having trouble dealing with where that high is going to place Thu and Fri. Secondly, the air mass coming is cold, but not super incredibly such. I remember here in bayside Baltimore County it was 17 F and snowing teensy tiny little crystals. I had never seen such heavy snow at such temperatures in the coastal plain. The high that's coming may give us a day in the low 30's with overnights in the 20's...comparatively way warmer than the Feb 03 storm. The surprise could be in the prolonged period of icing that may develop Friday into Saturday.

3. If an arctic air mass is coming down then wouldn't that create lots of cold air damming to take place?

There is already deep concern about the cold air damming signature that's developed on some computer models for Thursday into Saturday. Even though a higher sun angle this time of year might negate some of the storm's effects by warming cloud tops, incoming solar radiation warming roads and parking lots...there is still going to be plenty of cold air to keep the ground cold. It's already arrived in force, for Monday at noon in Dundalk I observed 75 F while we were having lunch on our deck, and now at 9:30 PM it has dropped to 42 F. I think NWS offices are picking up on the potential for a major ice storm to follow the first round of snow, and you'll see this reflected in Special Weather Statements starting to fly by Wednesday morning with Winter Storm Watches posted by Wednesday night.