I'm watching a very interesting system that may be developing for the Wednesday/Thursday time frame here in the DC area.

Most models show a phased system moving out of the Southeast, off the coast of the Carolinas and then up the coast.

The GFS run for Wednesday night shows a low pressure system rapidly intensifying off the coast

and throwing moisture back into our region.  The temperatures here are noteworthy.  The blue line is sub-freezing temperatures and we are north of that line.  This model suggests that the precipitation that falls will fall in the form of snow.

Interesting.

The total precipitation forecast from the same model through the duration of the storm for us looks like this:

It's a little tough to see but our area falls within the 0.1 - 0.5 range with a very sharp gradient towards the coast.  Using the old 10-to-1 ratio for liquid precipitation to frozen, this implies 1-5 inches of snow for our area.

More interesting.

As always, this is dependent on a lot of things but especially on storm track.  A track closer to the coast would mean more precipitation but also warmer temperatures as air is pulled from the relatively-mild Atlantic.  A track further from the coast would mean less precipitation - and a few solutions have a total miss with the storm moving off the coast too far to affect our weather.

Here's the GFS estimate for snow cover after the storm:

In this scenario, Delaware gets the bulk of the snow but you can see how close the areas of heavier snow are to this region.

The bad news in all of this is that the storm is likely to slow down and pound areas affected by Sandy (the Jersey shore especially) with winds, rain and surf.  Just what they don't need.

Let's see what the evening models hold but for now, there's a chance that some rain will start Wednesday, possibly changing to snow as nightfall approaches with better chances of snow north and west of DC but less overall precipitation the further west you go.

That's the weather forecaster in me being careful with the forecast.  The GFS above has no such hedging.  If I made a forecast entirely based on that, I would say "plan for snow Wednesday night".

We wait for the evening model run.