Update Thu @ 7:34 AM — Last night’s models continue with a generalized 3″ snowfall starting about 10-11 PM tonight and ending about 7-9 AM Friday.

Blue column is the latest model forecast. The NBM has a large range of possibilities from 2.5 (25 percentile)- 6.0″ (75 percentile)

Updates later today. Stay tuned

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Updated Wed @ 8:38 PM — Tonight’s models continue with a generalized 2-3 inch snowfall from a low pressure system expected to form and move off the coast Thursday night into Friday morning.

Here are some current raw model snow forecasts for Blue Bell, PA as of Wednesday afternoon —

After the storm departs on Friday, gusty winds are expected.

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Updated Wed @ 7:23 PM— Another quick update for Thursday night’s expected snowfall. Models are predicting snow in the range of 2.5-3.5” of snow over the area. Snow starts between 8 and 11 PM and tapers off around noon Friday. Another update later this evening.

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Updated Wed @ 7:09 AM— Just a quick update for Thursday night’s snowfall. Latest GFS has 1.5 inches for snow, the NAM has 3” of snow by Friday morning for the immediate Philadelphia area. I’ll update this evening in more detail.

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Updated Tues @ 10:25 PM— Regarding Thursday night’s snowfall, tonight’s models (NOAA server is back up) are trending towards lesser snow amounts, in the 1 inch range. Stay tuned.

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Update Tue @ 8:53 PM — Light freezing rain possible early Wednesday morning according to the NBM. Just a slight chance.

Temperatures below freezing at 7 AM and ground temperatures will lag surface temperatures. Doesn’t take much to have slippery conditions.

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Updated Tues @ 6:59 PM— One of the two main NOAA’s servers that I use to auto download weather model data has been down today. So I haven’t been able to look at most models. I’m working on switching over to another server. (Easier said than done.)

I did manage to get the NBM model and it shows good chance of freezing rain early morning Wednesday for areas north of the city.

This afternoon’s Canadian GEM show very light freezing rain moving from south to north from 5 AM through 9 AM Wednesday.

I hope to have more to say later this evening.

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Updated Tues @ 01:40 PM— The possible snow late Thursday is, as usual, is too far in the future to pin down yet. As always, there’s considerable model spread. The GFS has the most snow for us and the NAM the least right now.

Just to give a sense of things, this most likely will be a 2-3 3-4″ range snowfall based on the current GFS and NBM, starting Thursday evening and ending Friday morning. It currently isn’t expected to intensify like the storm this past Monday.

I’m sure the details will change. Stay tuned.

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Previously Posted Mon 8:05 PM —

A dip in the jet stream has brought colder temperatures. Another dip will spawn another low pressure system later this week, just as it did Sunday night into today, Monday.

The models are uniformly forecasting another low pressure system to affect our area from Thursday night into Friday morning. This storm may again affect eastern areas into NJ more than areas in Pennsylvania. Precipitation will be all snow.

It’s too soon to assess specifics.

Cold weather following the Friday storm will last into Saturday. Next Sunday may be briefly milder.

Updated Fri @ 9:58 AM — Some higher-resolution data coming in for Sunday’s forecast. Rain in the early morning. Then a break in the showers early afternoon, with even some sunshine.

Temperatures in the 60s! Becoming very WINDY. A line of showers moves through 4-6 PM with the cold front. Temperatures drop with gusty winds. Showers may linger into after midnight, then possibly change to snow showers.

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Updated Fri 9:29 AM — Last night’s NAM and Canadian GEM and European ECMWF have followed the GFS in predicting another area of low pressure developing. However, for snow lovers, this low pressure system will, at most, brush us as it departs northeastward. Currently, at most, a coating of snow possible at daybreak Monday. This coating is most likely possible in southern NJ, Cape May—

Just not a large enough cold air mass or amplification of the jet stream for it to give us snow here. But I’ll keep an eye on this. My regular weekly, “Weekend Weather Forecast” will be posted this evening.

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Update Thur 6:40 PM— The GFS forecast below for Sunday is currently an outlier, with the European (ECMWF) Canadian (GEM) and German (ICON) models have the precipitation missing us, exiting to our south. This is an evolving forecast.

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Cold air, which has been conspicuously absent this past month, has been building up in northern Canada and indications are that it has reached enough critical mass to plunge (at least temporarily) down into the continental US and into our area by the end of this weekend.

A strong frontal boundary has developed separating the very cold air from unseasonably warm air. Low pressure systems have been developing and ejecting towards us in this warm sector, giving us the clouds and occasional showers these past few days.

Currently, the cold air is expected to plunge southward and then eastward. Depending upon how far southward vs eastward will determine the shape of the jet stream and the path of low pressure expected to develop on the front.

New Years Eve

Cloudy and mild. Rain doesn’t get here until 2-5 AM Saturday morning.

Saturday

Some rain in the morning. Heavier rain by mid afternoon.

Sunday

This forecast is still evolving. This is preliminary. Some rain early, becoming WINDY. The front comes through either mid afternoon or later, somewhat influenced by the degree of low pressure development. If the low tracks northward, the usual rain-snow dividing line may set up here.

Here’s the latest GFS model, just available —

Stay tuned.