The weather for New Years Eve will dry, as a weak cold front is expected to move through with showers early Thursday morning and things dry out for New Years Eve. 

However a warm front associated with a low pressure system in the Midwest brings in rain New Years Day (Friday) to start out 2021.

The general pattern this week is for our area to be under the influence of an upper ridge pattern and a mild moist flow from the southwest ahead of this low pressure system moving up  to the west of us through the Great Lakes on Friday—

After the rain moves out Friday night, Saturday should turn out dry and mild with high temps in the low to mid 50s.  I should mention that average temps are 41 º high,  25º low ( Blue Bell) this time of year. 

Yet another system moving in Sunday brings more rain as a coastal system tries to develop off the coast.  The upper air pattern does NOT favor development of a nor’easter or any snow from this system. 

In fact, snow lovers right now will have to wait for a pattern change. As mentioned in several posts recently, my pattern assessment is “lack of very cold air” to our north. 

Thursday evening, Christmas Eve, is looking quite rainy and windy. Friday cold, windy with clouds. The weekend looks to be dry and cold.

A very strong cold front will move through Thursday evening and night, Christmas Eve.

An extremely sharp dip in the jet stream will usher in a cold front, that most models have moving through between 1 and 2 AM Friday morning.  Preceding and accompanying the the actual frontal passage will be fairly heavy rain (1+ inch)  but also very high wind gusts. 

Rain starts late Thursday afternoon and gets heavier during the evening and night-time hours. Winds will pick up as the evening progresses. Wind gusts of 50-60 mph are predicted with the highest winds with the front passage about 1 AM Friday morning.

There was some thought over the weekend that low pressure might develop along the front, but all models have ruled out snow here with the exception of snow flurries.

Cold air filters in during the day Friday on brisk winds. The early morning temperatures will be the high temperatures of the day and temperatures will fall during the day. Wind chills in the teens.

Instability cloudiness will also be with us Friday and a snow flurry can’t be ruled out.

Saturday will be cold and still a bit windy. Highs will struggle to reach 30º. Right now it looks to be sunny, but it’s difficult to time upper air disturbances which may bring periods of clouds.

An approaching storm from the Midwest will bring some increasing cloudiness during the day on Sunday.

The weather has been mild and quiet recently.  However,  changes are expected over the next week as a highly amplified pattern develops. The trend is a change to much colder weather next week.

Tomorrow, Monday, will be a rainy, windy day.  Jet energy from both the northern jet and southern jet will phase and result in deep low pressure development over the Great Lakes.  Some of that energy will move down to cause GUSTY WINDS (up to 40 mph)  for us on Monday—

It will still be mild on Monday, but colder air moves in later Monday and Monday night.

Notice that the jet flow makes a loop over high pressure in the Mid-West and another high energy impulse is waiting in the wings for later in the week.

There’s much uncertainty about timing of this next impulse with how these things are going play out later in the week, but some models are showing snow for central and western Pennsylvania.

For us, it will be rainy, windy and cold Friday and unsettled and cold next weekend. NO SNOW for us at this time. Stay tuned.