My Weekend Outlook: The Cold Continues, With Storm Madness Approaching For Sunday. Most Of Us Will See Wintry Precip.

Discussion:
Friday AM: 11/30/07

A very complex and tricky storm will threaten much of The Delaware Valley Region later this weekend. A Classic Battle between Cold Air Damming (CAD) East of the Apps, and Warm Air Advection (WAA) will converge on Sunday, As cold High Pressure over Quebec, and An approaching storm from the Southwest produce an nice overrunning setup. The cold air supply will be very fresh, and will likely hold tight with a classic CAD signature for much of the Northern M/A States and The Northeast.

At this time the NAM Model is continuing a trend to the Colder solution, as the GFS Model is also catching the strength of this CAD signature. With a 50/50 Low (Newfoundland Low) and a Cold Surface High Pressure over Quebec. This will help to flatten the flow and suppress the storm, from moving too far NW of the region, and prevent any WAA to overtake the cold air in Place.

In addition, this setup will support the main low moving through the Ohio Valley and Lower Lakes, to transfer it's energy to a Secondary Coastal Low, just off the Northern M/A Coast. It now appears this will occur, later Sunday Night, between the NJ Coast, and Long Island. This would quickly cut off, and prevent and additional WAA from NE PA into Southeastern New England, and begin the Cold Air Advection (CAA) process to begin NW of the Center, as Heights begin to lower quickly. So from NE PA and NW NJ into the Hudson Valley of NY, if any changeover to Ice or rain occurs it would be Brief on Sunday Night.

On Monday morning, the storm strengthens off the Southern New England Coast, and moves NNE to the Gulf of Maine, where it bombs out to a Sub 980mb low, during Monday Evening. This will drive and pull in very cold air, for much of the M/A States and The NE for Monday Through Wednesday. Strong NW winds will occur throughout the region, with CAA and LES machine turned on, some snow showers and flurries will reach the coast on Monday night and Tuesday, from the Delmarva and on northward into the NE.

Overall, I see this storm producing the Heaviest Snow Accumulations, from The Hudson Valley(Interior Southern New England) to much of Central and Northern New England. I'll have My Final Call out with a Snowfall Map on Saturday.

For The Delaware Valley Region:
My best estimates for Snow and Ice Accumulations: For Sunday into Sunday Night.

1. A general "Coating" to 1" for PHL and the surrounding Suburbs of SE PA, NJ, and Northern DE.

2. Areas further N & W from RDG to ABE into Central and Northeastern NJ, could see 1" to 3" of snow and Ice.

3. NE PA(The Poconos) into NW NJ: 3" to 6" amounts are possible.

The Ruggie Weather:
Weekend Forecast for The Delaware Valley Region.

Friday:
M.Sunny and Cold. Highs in the mid to Upper 40's

Tonight:
M.Clear and Cold. Lows in the mid to Upper 20's.

Saturday:
M.Sunny early, then increasing Cloudiness during the afternoon, continued cold and Breezy. Highs in the Upper 30's to low 40's

Saturday Night:
Cloudy and cold with Light Snow developing later at night and towards morning. Low in the mid to Upper 20's.

Sunday:
Cloudy and cold with snow early, then mixing with and changing to Sleet and Freezing rain, south of PHL, towards noon. Precip changes over later in the day, or evening N&W of PHL.
Highs near 40 from PHL S&E to the mid 30''s N&W of PHL.

Sunday Night:
Cloudy with mainly Rain from PHL S&E tapering off late at night. lows in the Upper 30's
Mixed Precip and Rain, N&W of PHL. Lows in the low to mid 30's.

Take Care,
Ruggie