This is A Really Difficult Forecast - Maybe Less Snow?

Here we are, a few hours from the onset of precipitation and things aren't very clear yet.  This sort of storm setup has so many things that could make a forecast go wrong.

This scenario is very complex and I don't envy the official forecasters at the National Weather Service who have to make a final call that will affect so many people.

I have some concerns based on the latest models and radar.

The newest model runs show the heaviest axis of precipitation shifting somewhat to the north and east.  They also show the low pressure area itself forming closer to the coast - which could give us problems with mixed precipitation.  Finally, some of the upper-level patterns suggest that we in the DC area could experience issues with the dry slot again (like we did early Saturday morning which cut down on accumulations somewhat).

On the other hand, the storm that is expected to develop will be intense and slow-moving.  Models continue to put out a lot of QPF for us which increases the confidence for a major snowstorm.

I'm going to watch things develop for a bit.  In no way am I suggesting that this storm will not happen.  There's just much more uncertainty about exactly how all of the elements in the atmosphere will come together - a process that's happening even as I type this.

But I think there's a chance we get less snow than is forecast.  Right now, the forecast is the same as it was last night:

8-12 inches from about Fredericksburg north to DC
12-16 inches from DC to Baltimore and points west
16+ from Baltimore northward to Philly

but after looking at things this morning, I think those amounts may need to be lowered some in the DC area and southward.  Maybe to an average of 10 inches in the immediate DC metro, less south, more north.

In fact, if I had to do it right now, I'd just shift those values northward and put in a new range for south of DC.  So:

4-8 from about Fredericksburg north to DC
8-12 from DC to Baltimore and points west
12-16 from Baltimore northward to Philly

More information when I have it!