It has been a very polarizing day for the forecast models today. Last night, after I posted, all the models showed the storm heading out to sea, sparing the area of snow/wind. But, today the models have shifted west and many have been showing a fairly substantial snowstorm for the area. If you read my last post, scenario 1 looks to be the most likely and the one I am predicting.

About the storm:

A piece of energy sitting off the North Carolina coast will phase with a negative trough and form a nor’easter. This nor’easter, from the influence of the trough, will stay close enough to the coast for precipitation to fall with heavy ne winds in our area. Even though surface temperatures will not start out at 32 degrees tomorrow afternoon, dynamic cooling will occur when the snow starts to fall. This is when cold air aloft comes down to the surface and lowers the temperature to near 32 degrees. The snow that falls will be very wet and heavy; large snowflakes.

Timing: 

12 PM-2PM: Light rain starts to fall

2 PM-8 PM: Eventual changeover to sleet/snow as dynamic cooling occurs

8 PM-6 AM: Snow and wind

6 AM-12 PM: Snow winding down and may end as some rain

Snow Totals:

I am calling for a general 2-4 inches of snow to fall in the Philly area tomorrow. A few models have shown totals upward near 8-12 inches, but considering the time of year and snow ratio, totals should stay lower than what the models project. In north jersey and Catskills I called for 3-6 inches because of elevation. The shore and NYC should have a mix, which will keep their accumulations near zero. Of course things could change over the next 20 hours or so…so stay tuned.

Repercussions:

Much like the Halloween storm last year, wet heavy snow will fall with some trees still having leaves on their branches. As a result, widespread power outages could occur on Wednesday night/Thursday morning as the snow weighs down these trees and power lines. There will be a few school delays/closings Thursday. Because most roads will be snow free (it has been too warm recently to support much snow to stick on the roads), most schools will make the decision based off of how much damage the snow will cause.