Wednesday, December 30, 2009

My New Years Forecast. A Possible (2) Part System with A Mixed Bag Of Precip. Windy & Very Cold For The Weekend.

11:30 AM Update
Thursday 12/31/09

Round #2 on the way For Tonight into Early Friday AM !

Many areas across the Delaware Valley to NYC areas received anywhere from 1" to 2" of snow with this mornings thump of wet snow and mixed precip. Here in Pittsgrove 1.1" of snow, so the Coating to 2" call was good, and a general 1"-3 for NW burbs to NYC also verified. Much of the NYC area is mainly reporting 1.5" to 2.0" coming in up there. Reports between 2"-3" across parts of Eastern PA to Northern NJ. This has now ended in most areas and is pushing offshore. The remainder of today will remain cloudy and cold with a few patches of light drizzle, Highs will remain in the mid to upper 30's.

NWS Mt Holly: Snowfall Reports

The part # 2 that I spoke of yesterday is a good bet now, but will be moving in a little earlier than I forecasted yesterday. So as I said it's tweak time, and I'm now updating part #2 of this call. This will cause some problems for travelers tonight into Friday morning. A second round of precip will be moving back in during the evening hours tonight. Many areas will start as light rain or mixed precip, then change to wet snow and mixed snow/sleet/freezing rain from west to east later this evening into the overnight hours. Temps will drop to the upper 20's and lower 30's overnight, so untreated roads will become slippery and hazardous later tonight.

I'm forecasting and additional Coating to 2" of snow to fall tonight, with some NW suburbs of PHL seeing 1"-3". These higher amounts are most likely to occur from LNS to RDG to just NW of PHL.

From PHL into NE MD, Northern DE and interior Southern/Central NJ, I'm forecasting a Coating to 2" from later this evening into early Friday AM.

A Coating to 1" from Central DE to Extreme Southern NJ and this includes coastal regions of SJ and DE with the exception of Southern DE where little or no accumulation can be expected. Most of these areas will see light rain, changing to snow and mixed precip, before ending overnight into early Friday morning. So I don't expect any real travel problems down there.

New Years Day:
Expect some left over light snow and mixed precip during the early morning hours, then remaining Mostly Cloudy with a few periods of light snow/sleet/and rain during the day. This will be spotty and light and cause no problems. Highs will be chilly and temps remain between 35-40 degrees.

Saturday and Sunday:
Windy and much colder with clouds and some sunshine during both day, and Considerable cloudiness at night. Some flurries are possible on Saturday with Highs in the upper 20's to lower 30's.

On Sunday we could see a round of snow showers and flurries during the afternoon and at night. A coating to 1" is possible for some spots, so this need to be watched, as our big storm off the northern New England coast, begins to retrograde West and SW towards central New England. So, Some backlash snow showers/flurries could work there way into the PHL and NYC areas Sunday into Sunday evening. Very windy and cold conditions remain with Highs in the upper 20's and lows in the teens and lower 20's.

Have a Happy and Safe New year !

Wednesday 12/30/09

As I've discussed over the past several days, the system for Thursday into New Years Day is quite tricky and complex. This continues to be the case and could turn into a nowcast situation, especially for New Years Day. Taking all things into account, with the pattern, models, teleconnections, and past coastal storms over the past month, this could be one system with some surprises. I have enough information to put out a general forecast and idea at this time, but this could be tweaked or updated as I see exactly whats going on tonight and tomorrow morning.

This system will likely come in 2 parts for our region. The first and more substantial part, will come from a weak area of low pressure moving Northeast from the Mississippi and Tennessee Valley during tonight into tomorrow. This will then exit off the M/A coast and bring a period of snow and mixed precip to the Delaware Valley later tonight into Thursday afternoon. Temps at the surface and aloft will be just cold enough for mainly wet snow at the start, but then change to some mixed precip and light rain by noon. This changeover to rain is most likely for areas mainly south and east of PHL. Only a change to mixed precip can be expected for areas NW of PHL, before precip tapers off during the early afternoon.

Across much of SE PA/Interior Southern/Central NJ and Northern DE, Most of these areas will see a Coating to 2" of snow accumulation during Thursday morning, but some far NW suburbs of PHL could see 1"-3" of snow.

Further south and east over the remainder of DE and Extreme southern NJ, only a coating can be expected, but most areas will see little or no accumulations down at shore points. Temps will rise above freezing during the late morning and afternoon hours into the mid and upper 30's. Skies will remain cloudy for Thursday afternoon and night with only a chance for a few periods of light rain and possibly some Mixed precip south and east of PHL. Expect a period or two of mixed snow and rain/ or even Freezing rain for points NW of PHL during this time frame. Lows will be in the low to mid 30's for Thursday night.

New Years day and Night become tricky and this is where many models are having the most problems. Most are developing a second system, near the SE coast and moving it too far east and well offshore during Friday and Friday night. I'm thinking the models are having big problems in handling some key u/l features. So with that, I'm going with a storm closer to the coast and a few periods of rain and mixed precip, then changing to some wet snow/snow showers for Friday afternoon and early evening.

Even if the second feature doesn't materialize as I think, I'm still thinking just enough u/l energy moving through, will at least cause a few periods of mixed precip and snow for Friday afternoon and evening. Highs on Friday will be in the mid to upper 30's NW, and in the upper 30's to lower 40's SE of PHL, then temps fall later in the day.

Some light snow accumulations are possible from this second system and u/l energy as well. It's too early to say for sure if this amounts to anything, but at this time I don't think we see much, but this needs to be watched closely. I'll also tweak this more tomorrow or tomorrow night, if needed.

Over the weekend, windy and very cold temperatures return. Some flurries or snow showers are possible for Saturday with highs only near 30 and wind chills in the teens. Sunday expect P.Sunny skies with a flurry or two during the afternoon. Continued windy and very cold with highs in the mid to upper 20's.

Have a Safe and Happy New Year.



Anonymous said...

Long island snow amounts???




For Thursday:

1"-3" for NYC and LI
This also includes Interior Central and Northern NJ, down to near Trenton.

SE PA & NW Suburbs of PHL = 1"-3"

For PHL and Points S & E into Northern DE and much of Southern NJ 1" to 2"

For Extreme Southern and coastal southern NJ into Southern/Central DE a general Coating to near 1"


Anonymous said...

I don't know why I see this... but I really do see the 2ed half of the winter being more snowy then the first half... Glenn might be on to something.. Do you see this happening???