2ND CALL POSTED >> https://paweatheraction.com/second-call-forecast-for-mondaytuesdays-major-winter-storm-amounts-timing-included
A significant Winter Storm is targeting the area beginning Monday and lasting until at least the first half of Tuesday. For those only interested in the First Call Map/Key, that is at the bottom. Here is an in-depth discussion.
Snow will overspread the area from the Southwest part of the state towards the Northeast part of the state beginning mid-morning Monday. The system should wrap up by Tuesday noon time.
Here’s the latest model guidance breakdown.
Like all guidance, GFS has all of us starting off as snow. However, it shows a changeover to rain for the Southeast part of the state and a mix of sleet and freezing rain for our Central areas. Farther to the Northwest is an all snow event.
The Canadian model is much colder than the GFS. This shows a major snowstorm areas points North&West of a line from Harrisburg to the Poconos. This would also indicate significant freezing rain for Eastern PA.
Although the European still starts everyone else as snow, it quickly turns most areas in Pennsylvania to Rain. This is the warmest of all models. Notice where the arrows are pointing in the above map. That is your rain/snow line. Notice how areas in far Western PA are the only ones cold enough to support snowfall. We do not believe this will be the case..let us explain.
Here’s a look at the upper air pattern up at 500mb via the European Model: Notice the highlighted red box. This is a second piece of energy that will help “kick” this system coming Monday into Tuesday further East. It would be nearly physically impossible for the low pressure to cut far enough west that nearly the whole state rains. Now if this second piece of energy trends further west, then yes it is possible. However, that does NOT look to be the case.