Very Unsettled this Week, Turning Colder with Some Frozen Precip possible for Tuesday Night.

Discussion and Forecast:
Monday AM: 12/15/08
For The Delaware Valley Region.

An Unsettled and rather Damp week is likely for much of this week. We start out with very Mild temperatures today as temps reach the low 60's. A strong Southwest flow, and approaching Cold front will help to surge very mild air into the area today. A strong cold front and High pressure will begin to move in tonight and tomorrow, as temps fall quickly into the 30's and 40's behind this cold front for later tonight and Tuesday. Some showers will develop later today and this evening ahead of this front.

On Tuesday a northerly flow of colder air will filter in behind this front, as strong high pressure moves into the Eastern Great lakes, then moves east into Northern and Central New Engalnd Tuesday night into Wednesday. Temps will remain in the Mid to Upper 30's, north of PHL and in the upper 30's to low 40's, south of PHL. Periods of rain are likely for much of Tuesday as well.

Tuesday Night things get very tricky, as some frozen precip along with colder temps are in the cards for many areas north of PHL. I expect a mix of snow/Sleet and some Freezing rain to begin later Tuesday afternoon into Tuesday evening over the Lehigh Valley and spread south into the northern and western suburbs of PHL during the evening and continue into the overnight before tapering off and ending. Temps will be in the lower 30's.

Some light accumulations are possible north and west of PHL, My best estimate is for a Coating to 2".

For areas south of PHL some of this rain will also mix with some sleet and possible wet snow later Tuesday evening into the overnight hours. This will occur mainly over northern DE and Interior sections of Southern and Central NJ. Temps will be in the low to mid 30's. Little or no accumulations can be expected in these areas.

For Wednesday the frontal boundary lifts slightly north of the area, but we remain chilly and some scattered showers will continue. Highs will be in the Upper 30's to low 40's.

Thursday: Mostly Cloudy skies and continued chilly with highs in the low to mid 40's. A shower or two is also possible.

Note:
Tomorrow I'll have more on this potential of Snow and Ice event for Tuesday afternoon into Tuesday night. As I said this is a very tricky setup and some changes will likely be applied to my forecast tomorrow. Stay Tuned !

Take Care,
Ruggie