In the 3-6+" area don't be surprised to see over 6" but also don't be surprised to see just 3" The mesoscale set up is going to set up banding that trains over the same are resulting in some high amounts.  The latest SREF guidance wants to edge that a little more NW and I caved in a little bit by extending the 3-6+" area more NW.  But I didn't go too far because I think the best set up will be somewhere where I have highlighted.  

I see arguments for this area being more NW and SE.  The radiational cooling tonight could complicate the exact spot a little bit by messing up the thermal fields.  the thinking behind this is that precip starts as snow further east than modeled and stays snow shifting the rnsn line to the se and best forcing se.  However, I do not expect this to be a major shift (aka keep a close eye Philly and South of Trenton).

The stronger system might argue for more NW movement of the dynamics like SREFalluded to but if this were to occur I still like my dark blue shading regardless.  

This map cannot be worse than the eagles...I hope :)

Here is a nowcasting blog to hold you over until my nowcasting starts after the eagles game!:

NOWCASTING

-----------------PREVIOUS BLOG AT 6:50PM-----------

It is that time...

Before I show you the map, Important things to know:

1) UPDATING map at 11pm with nowcast

2) Basing this forecast off trends and adjusting favorable models to those trends. It is a lot harder than it sounds!

3) This storm will overachieve for snow lovers in some areas and be a disappointment in others as always. 

The Instability

Banding is going to be likely right along the rn/sn line extending to portions N and W with the storngest frontogenetic forcing.  However, one of the wildcards I have been talking about is the potential for this low to develop closer to the coast and be stronger! This would allow for a longer duration of the precipitation.  

Models have hinted at some convective instability aloft mainly on GFS, but other guidance is highlighting slantwise convection.  This would only be possible if this system were to slow down and develop more.  The ingredients are certainly present for such phenomena.  

First thing to note is the location shaded in blue (at this time) is very strong lifting and on the anticyclonic side of the jet streak in the northern stream.  This not only leads to the stronger lifting but provides weak intertial stability...

And also reflected on the SREF here:

Why is this important?

This could allow for a few hours of 1-2"hr rates of snow training over a particular area.  I bring this up because of guidance hinting at a stronger coastal and the fact the NAM has shown an inverted trough across a similar area.  This could lead to a snow jackpot somewhere in my highest totals.  

Other Wildcards:

-Southern stream is more active and convection will get going shortly over E TX/AR/LA.  This could continue to lead to a more amplified set up resulting in a chain reaction of deeper trough and stronger coastal low.  This could bring more cold air into the situation making me bust in areas of rain.

- Dynamic cooling and melting induced cooling.  I factored these two in as best I could but with models adjusting it will most likely need to be adjusted again!

THIS WILL BE ADJUSTED 11PM TONIGHT!