Bolaris: Nor'easter in the wings?
Another polar shot will arrive Monday night sending readings tumbling down between 10-15 degrees, colder north and west.
Tuesday will be the coldest day of the week with temps in the mid-20s and lows by Wednesday morning in the single numbers along with a few record lows.
The big concern for Wednesday night and into Thursday is the growing threat of a Nor'easter.
Models have come closer in agreement with a storm system ejecting from the Gulf of Mexico and moving it north along the East Coast, intensifying as it does so.
The European model, which is usually one of the more reliable, has it as a full-fledged Nor'easter complete with the threat of heavy snow, sleet, freezing rain (although at this time the freezing rain does not appear extensive) and a change to rain in places.
Global models have come around and indicate a storm tracking up the East Coast but more offshore, meaning a colder conclusion with less precipitation possible, but more in the way of snow and not as intense.
Snow would start Wednesday night for everyone, before changing to a mix of snow, sleet, freezing rain and rain on Thursday and then ending sometime later in the day on Thursday.
It's real tough to determine rain/snow line with this storm right now, but if I were to take a look at climatology for these type of storms, the line would usually be north of the Pennsylvania Turnpike and across northern Chester County, central and northern Montgomery County, through central Bucks County and cutting east through northern Mercer County, into northern Burlington and Monmouth counties in New Jersey.
Across southern New Jersey, central and southern Delaware and all coastal sections it would be snow to mix to rather quickly all rain.
Philadelphia could have an extended period of snow and sleet before a changeover to rain.
Again, this is an extremely complicated system, starting to take shape, and I'm sure I will be adjusting quite a bit over the next 48 hours, but I wanted to give you some sort of time frame and general outlook so you can start thinking about your alternate plans, just in case.
I have increased my possible snow accumulating level to moderate, meaning a 50-60 percent chance.
Will keep you updated.