WEATHER BLOG: Ball Rolling

We 'started the ball rolling' yesterday by predicting a general 1-3 inches of new snow out of this upcoming event, knowing that some 'fine-tuning' would be in order... Some of the questions we had to address included: "Will a southeast wind developing near the coastal plain cause snow to mix with, or even change to rain?" and "Could there be a swath of heavier snow, bringing greater than 3 inches to some parts of the mid-Atlantic or Northeast?"

Addressing that first item, the vertical temperature profile still looks plenty cold enough to support snow at the onset of precipitation across eastern Pennsylvania, New Jersey and New York tomorrow morning, so we would tend to look for 'a bump in boundary layer temperatures' during the day to try and determine precipitation types beyond lunchtime... And, that appears as if it will happen near greater Philadelphia, along the Jersey Shore, in Delaware and across central and eastern Maryland tomorrow afternoon...

That tendency for 'mixing' will cut down on the accumulation potential somewhat... But, the European's median precipitation totals (the liquid equivalent) have been CONSISTENTLY HIGHER than other model sources within the last 24 hours in: the Lehigh Valley, the Lower Susquehanna Valley, many of Philadelphia's northern and western suburbs and in northwestern New Jersey... In this "sweet spot", where there should be mostly snow (and very little, if any rain), we believe there'll be a 3-6" accumulation through early tomorrow night.

Saturday, some sun returns and it will become milder, but Sunday and Monday should be dry and cooler again...