Thursday Storm Outlook: A Thread The Needle Situation for Sunday

Good morning. I want to expand on what I discussed yesterday regarding possible winter storm development Saturday night into Sunday.

I see many places simply saying we have a snow event coming and posting maps like this...

I would be very careful with this however as it really is a "thread the needle" type storm. What I mean by that is we do not have cold air that will be locked in ahead of this system. That means the track, intensity and precipitation type will all depend on the exact timing how how the northern and southern jet stream interact. The energy we are speaking about is seen below...

Few things to note here when looking at these two circled areas:

1. If the flow becomes too fast they do not interact and you get a very weak precipitation event or nothing at all
2. If the northern piece is too slow and more amplified then the southern piece brings in too much warm air ahead and we get rain for the mid Atlantic and even southern New England
3. If the northern piece if just fast enough but not too fast, allowing it to interact with the southern piece at just the right time, then we get what the GFS is showing below...

In the image above we have a northern Mid-Atlantic to southern New England snow event with a general 2-5 inches of snow. Areas to the south (Phili, Balt, SNJ) see mixing and rain Saturday night into Sunday morning.

So what I think happens? 

At this time I favor Southern New England being the main target zone with Northern NJ and central to NE PA getting in on the action as well for a light to moderate snow event. I do not like the prospects for CNJ and the big Cities (ex Boston). It appears a storm will develop but the cold air is too marginal in my opinion. The timing is Saturday night into Sunday morning.

Lets see how this evolves.

I will have a map out tomorrow if necessary.