Accumulating Snow/Sleet & Ice, Likely Friday into Saturday AM. My Call for The Del.Valley & M/A.

My Call: For The Delaware Valley and M/A Regions.

For: 2/22 - 2/23 Snow and Ice event.

Issued: Wednesday Evening 6:00 PM

Discussion:

As we celebrate George Washington's Birthday on Friday, it looks like He's worth more than a Dollar Bill, with this event. As many of you know, I've been talking about an Accumulating snow event for much of the Central and Northern M/A States for later this week. I have no big changes to my first general discussion, as this is a classic overrunning event, with front end snow moving into the Delaware Valley, for Later Thursday night and Friday morning.

My initial estimates were for a general 3" to 6" of snow across the Delaware Valley Region.

Now for my Final Call on this storm. This is what I'm going with, for Total Snow and Sleet Accumulations, from Later Thursday night through Saturday.

3" to 6" for areas North and West of PHL. This from RDG/ABE to just north of TTN and much of Northern Most NJ.

I'm going to trim this back in the southern zones to: 2" to 4" in PHL, Extreme SE PA/ Much of Southern NJ and Northern DE. This extends to northern MD and near the BWI area. NYC expect about the same amounts with 2" to 4".

From Extreme Southern NJ to Central/Southern DE and into the DCA areas: 2" or Less of Snow and sleet can be expected.

I'm very concerned with precip mixing with and changing to Sleet and Freezing rain, by later in the morning on Friday in these southern zones. But further north, this occurs during the late afternoon hours. This quicker change over, will hold back on snow and Sleet accumulations, especially near the PHL area, and Nearby SJ and DE.

WAA (Warm Air Advection) has not been a very good friend to snow lovers in the NYC, PHL, and the DCA areas this winter season, as most of the previous storms have cut to our west or North. The sad part is this storm system(weak) will pass to our south and slide to the VA Coast. We still can't keep it all snow, thanks POS NAO ! The NAO being Neutral to POS the entire winter season has also contributed to the "Well below average" snowfall for the respected areas. I do think NYC and Northern NJ, will do better this time around, as I'm forecasting a general 3"-6" snowfall for them.

So, Let's talk more about this setup. This is all about the interaction of cold arctic air, and an upper Level Split Flow pattern, that'll produce an overrunning situation to begin in the Southern Plains and Southern States, tomorrow and furthern east tomorrow Night. A strong flow due to both streams (P/J and STJ) coming together, from the Lower midwest and Tenn Valley, east to the M/A Coast, will allow this precip to stream eastward Thursday night and Friday.

With cold air in Place and High Pressure overhead and to our NW, this will allow this precip to be Snow initially, From the lower Ohio Valley, eastward to parts of the Central M/A, and all the Northern M/A States. A weak area of low Pressure will develop over the Mississippi Valley and move ENE to the VA coast by Friday Evening. It appears a second weaker wave of low pressure will follow behind the main storm, and prolong the precip over the Northern M/A States for Friday night into Early Saturday. This precip will likely be a mixed bag for the Del Valley to NYC and could change back to a period of light snow before ending Saturday morning. Some light snow and sleet accumulations are possible with the second wave.

Enjoy and Take Care,

Ruggie

TOTAL ACCUMULATION OF SNOW & SLEET

MAP FOR: 2/22 through 2/23

Click on map to enlarge.