Some Rain, Some Snow, Some Cold.

Today’s Discussion:

Got some issues to deal with today. To start last night’s snow turned out pretty much right on target, and it melted quickly: no surprise there. But on to what looked like an easy forecast, that is turning out to be one big challenge: Tuesday/Tuesday night.

That old SW low is moving now and will move NE toward our area and develop a new low pressure system off the VA capes. This means that warm air will not get highly involved, but there will be some good moisture transport. With a bubble of High pressure sitting to our NE in Canada, and with it not moving much that will really help to hold in the “cool air”.

Could it then snow tomorrow?  Well, the computer models are now showing it. The short range more detailed models are showing rain developing, then as precipitation gets heavier, it changes to snow for the afternoon and evening. In fact, most are showing anywhere from 2-5” snow!  I remain skeptical. Why?

1. Atmosphere is too warm. The lower 5000 feet must be below freezing. This will be done via #2.  
2. The precipitation must be heavy and steady enough to cool the atmosphere to become isothermal. There is some doubt regarding this.
3. Surface temperatures will be a little too warm. Mid-30 temperatures during the time when it might snow makes for more difficult accumulation IF it snows.

Thursday: Winters arrival.  The slowness of this SW upper low moving through is causing the trough to the west to “catch up” to it (not exactly correct but it gives you the idea), and thus there is little room for a wave to develop and bring us some rain/snow. There will be some rain/snow showers, but nothing too substantial.

​There is also a chance for light snow Sun night and Mon followed by a warm up for 36 hours and then more cold. Winter is here for now.