Temps gradually moderate with some mix to rain on Sunday ! Then "THE POLAR EXPRESS" Rides In for next week ! So, when do we get some Snow ?

Date: 12/8/2010
Wednesday: 6:00 PM
For: The Delaware Valley Region.

Full Discussion:

After several days of unseasonably cold temperatures and plenty of wind, things begin to calm down and gradually moderate, as we approach the weekend. High Pressure over the Midwest and Ohio Valley, will move east and settle over the region for Thursday and Friday. Temperatures will remain cold both days, but we can expect more tranquil conditions with lighter winds. Highs both Thursday and Friday will remain in the mid to Upper 30's, and overnight lows in the upper teens to mid 20's. Plenty of Sunshine can be expected on Thursday, but more in the way of cloudiness for Friday, as a warm front and weak clipper pass by to our north and west. A few scattered flurries or sprinkles are possible Friday afternoon and evening, mainly for points north of PHL. No big deal.

On Saturday, temperatures will moderate to near normal levels for this time of the year, as highs reach the low to mid 40's. So with P.Sunny skies and light winds, it should be a nice day.
Then my attention is focused on a developing storm system in the lower Midwest on Saturday and strong u/l energy. This storm and amplified deep trough, will spin up a surface low that will track into the Ohio Valley and Apps. on Sunday.

Snow, increasing winds, and very cold temperatures will occur north and west of this storms track. Parts of the Midwest and Ohio Valley will see significant snowfall amounts of 4"-7" along with howling winds and temperature in the teens and 20's for Saturday night into Sunday.

For us folks here in the Delaware Valley, and places east of the Apps, we will be on the east or warmer side of this storms track, so a southerly flow of milder air will move in for Sunday. Precip could start off as a period of sleet and snow later Saturday night or Sunday morning. This will quickly change to rain on Sunday as temps rise into the mid 40's to low 50's. Overall Sunday will be Cloudy with periods of rain, that will continue into Sunday evening.

As this storm pulls northward into New England Sunday night and Monday, a strong cold front will move through during Sunday night, ushering in colder air and increasing winds. Temps will drop back into the 30's later Sunday night and some showers changing to flurries and snow showers are possible into much of Monday. Some areas could see a coating to 1" of snow, mainly north and west of PHL. The Pocono's and NW NJ mountains could see 2"-4" on the backside of this storm for Sunday night and Monday.

As we head into next week, "The Polar Express" returns and will be here to stay for the entire week. A very deep trough and Polar Jet stream, will park itself over much of the Eastern US, as a strong block continues over the North Atlantic and Greenland. This is what we call a Classic Negative NAO. With this blocking in place, the trough will have no where to go, and will park itself here in the East. Plenty of very cold air will pour southward from Canada, into the Great Lakes/Midwest and drive Southeast to engulf the East.

For The Delaware Valley Tuesday through Friday, We'll see our highs struggle to get past the upper 20's to mid 30's, and overnight lows in the teens. Also, windy conditions can be expected from Monday through Wednesday. A few flurries are possible on Tuesday from the LES machine kicking in once again, but overall next week will once again be fairly dry.

Our friends in the SE States and Florida will once again have unseasonably cold conditions, and possible damage to citrus crops, due to freezing conditions during the early and middle part of next week. The good news, by later next week the SE and Florida should moderate and return to more near normal temperatures.

So, with all this unseasonably cold weather this month, many are asking me Where's the snow Ruggie ?? This type of pattern has produced the cold, but also dry conditions due to the u/l setup. I do see some changes coming with the Upper Level pattern and teleconnections that could favor our first measurable snowfall between the 18th and 22nd. As the trough and block begin to relax somewhat later next week, this will allow for a possible WWA (Warm Air Advection) overrunning event, and wave of low pressure to track to our south.

With enough cold air in place, and this system tracking from the Tennessee Valley to the M/A coast, I'm thinking this time frame (18th-22nd) is where parts of the M/A States and The Delaware Valley, could see our first 1"-3" or even 2"-4" snow event.

So stay tuned, I'll keep a close eye on this potential and have more on this threat sometime next week. Until then, stay warm because the overall pattern for the next 2 weeks will remain unseasonably cold. BTW, my winter forecast is off to a very good start, as I've forecasted a cold December and cold start to this winter, along with an intense LES machine, so far, so good. ;-)

Take Care,
Ruggie