The latest models are just becoming available this evening. Most models have it too warm for snow in the immediate Philadelphia area.  Some snow accumulation is possible far western areas.  The NBM (National Blend of Models) 75 percentile snow accumulation captures it well. (75% of the constituent models and their statistical members are equal or below this accumulation amount)—

 

The latest HRRR and NAM, just available, is consistent with this NBM forecast. There may be some snow mixed with rain in areas that show zero accumulation towards the mid afternoon.

Rain starts around 6-8 AM Monday and ends about 3-4 PM.  It may briefly mix or change to snow in the western suburbs as it ends.

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As for Thursday—

 

The models continue to show a major storm for Wednesday into Wednesday night.  It will be a stormy day by Wednesday afternoon with high gusty winds.  (At one point today, it appeared that warm air might move in, but the newest models are showing significant snow accumulation for Wednesday afternoon and night.) Here’s the latest GEFS snow totals by late Wednesday night—

 

Here’s the NBM 75 Percentile snow totals—

 

Very clear is the sharp cut off in NJ as temperature will be too warm for much accumulation there.

I’ll be updating during the week. Stay tuned.

The dip in the jet flow that gave us the thunderstorms Monday and the colder weather today will be an ongoing feature of the weather pattern this week and this weekend.

Low pressure developing near the Gulf of Mexico at the end of the week will move up the coast this weekend. Any other year, this would be a recipe for snow with the track of this storm, but the theme of this year so far is what I call “the lack of really cold air”. 

There’s much uncertainty with the development, track and timing of this low pressure system. The current GEFS model shows the low pressure system at 1 PM Saturday—

The German global ICON model has a more intensified low pressure system that takes a faster, more coastal track—

The Canadian global is somewhat similar to the GEFS—

All the models keep the storm warm enough for the precipitation to be RAIN for us on Saturday. (Some snow flurries early Sunday morning possible.)

Either way, Saturday looks stormy and Sunday looks to be windy and unsettled. This is an interesting scenario. Stay tuned.