Once again this winter we are heading into storm mode , for a major and prolonged winter storm expected to hit the area Sunday afternoon possibly lasting through early Tuesday
First off I just want to touch on tonight’s weather, a arctic cold front is swinging through the area , and with it will come clearing skies , very windy conditions and record cold temperatures , temperatures tonight will fall into the negative 0s for NE PA/ NW NJ and parts of the Lehigh Valley , 0-5 degrees for most of the remainder of the area and upper 0s to low 10s along the immediate coast, this will shatter records and make for dangerously cold conditions tonight through tomorrow with winds 15-20 gusts up to 30 wind chills will range from -5- -10 along the coast , to -15 to -25 for the rest of the region at times.
Jumping to the storm threat:
One piece of the storm developing from the sub tropical jet is approaching the west coast , this system is expected to merge with a arctic cold front/disturbance dropping from Canada. What’s going to happen is as the disturbance drives into the west coast a trough will dig into the middle of the country, this will pump up a bit of a ridge over the southeast and pump up heights
An arctic cold front will slowly drop south but will be forced to stall out in the vicinity of the area, where this front stalls will be crucial for the forecast as it will determine the track of the storm, there is general agreement of somewhere between southern NJ and just south of the Mason Dixon line, this will depend on how fast the sub tropical disturbance intensifies the quicker it intensifies the farther north the front will stall out and the warmer the storm will be
But overall I expect a major snow and ice event for most of the area besides maybe extreme southeastern NJ and with the stalled out boundary and enlongared orientation of the storm it will be very long duration
Model of choice for tonight is the GFS due to good consistency
We should start to see light snow and snow showers slowly fill in Sunday afternoon, as the front stalls out, with arctic cold to the north of it and warm air trying to clash in the precipitation will come come moderate to heavy by early Monday and last through late Monday night and perhaps lasting through Tuesday morning , any areas that get either rain or ice will turn to snow Monday night and areas that get mostly or all snow , it’s going to really pile up.
It’s too early for exact totals so I just came out with a storm threat map for now, the disturbances will be better sampled tonight and I will likely have more details on accumulation and location by tomorrow afternoon