monsoonmartin

Here’s an update on the storm expected this evening into Monday morning, with my own predictions about snowfall totals and cancellation probabilities.  As new guidance comes in and the storm continues to develop, I may send out an additional alert later on today.

Track is most important here. If the expected track shifts 20 miles to the east, we’ll get an inch or two. If it shifts 30 miles to the west, we’ll get 10 inches or more. If it stays on target according to the latest model guidance, we’ll get 3-4 inches. Temperatures are plummeting, increasing the “fluff” factor and nudging totals upward. Here’s what I think is going to happen:

Philadelphia and Bucks County, as well as much of New Jersey: light snow (perhaps mixed with rain at first) arrives around 5 or 6pm, heaviest overnight, tapering toward early Monday afternoon. Expect blustery conditions, particularly overnight and into Monday. Accumulating 12-15 inches, with isolated spots getting as much as 18-20 inches. Probability of school delay: 20%. Probability of school cancellation: 95%.

Chester and Montgomery Counties: light snow arrives around 6 or 7pm, heaviest overnight, tapering toward noon Monday. Expect blustery conditions, particularly overnight and into Monday. Accumulating 10-12 inches, with isolated spots getting as much as 15 inches. Probability of school delay: 25%. Probability of school cancellation: 90%.

Berks and Lancaster Counties: light snow arrives around 7 or 8pm, heaviest overnight and into early morning hours, tapering around mid-morning Monday. Expect blustery conditions, particularly overnight and into Monday; drifting will become an issue, especially in colder locations where the snow is dry and fluffy. Accumulating 6-8 inches, with isolated areas getting more. Probability of school delay: 30%. Probability of school cancellation: 85%.

Looking ahead... really cold on Monday night (low around 10) and on Tuesday (high of only 28) before we get gradually milder conditions throughout the week. Expect a high in the upper 40s and a bit of rain on Friday the 6^th. Even milder with a few showers over the weekend, and highs in the upper 40s to low 50s. Temperatures drop a bit for the following week, but nothing like the frigid conditions that will predominate from this evening through Tuesday evening...

Monsoon