So we made it through the first snowfall of the year(it's the second of the Winter season as who could forget the December 8th snowfall? The "snow bowl" at the Linc with the Eagles dominating the Lions in the second half for a comeback victory!) and although there was just 3.4" recorded today(which is a new record, shattering the old record of 1.5" set back in 1988) overall at Philly International Airport 9" was recorded from the Thursday evening to Friday morning event(interestingly enough the liquid precipitation altogether was 0.45".....that equates to a 20:1 snow ratio!). Here are the complied snowfall totals from around the region(courtesy of The National Weather Service in Mount Holly): http://mesonet.agron.iastate.edu/wx/afos/p.php?pil=PNSPHI&e=201401032039
Now the issue comes with fresh snow pack, a clear sky overnight, and calm winds; the temperatures tumble thanks to perfect radiational cooling(just think of it as you have a TV dinner and you cook it with the film on top; once you take the film off the heat escapes). Lows will be in the single digits and there is the potential for record lows to be broken overnight; granted these record lows are for January 4th as the coldest part of the day is just after sunrise(also of note is that almanac data is recorded from 12:00am-11:59pm):
Philly Int'l: 2 set in 1918
Trenton: -1 set in 1918
Wilmington, DE: -1 set in 1918
I also included some other major cities nearby as well as the data was available from both NWS offices in Mount Holly NJ and Upton NY:
Atlantic City: 0 set in 1918
Islip, NY: 10 set in 2008
La Guardia: 4 set in 1981
JFK: 8 set in 1981
Central Park: -3 set in 1918
Newark Liberty Int'l: 1 set in 1981
After a cold start we'll have plenty of sunshine for Saturday with high pressure directly on top of us so at least the wind will be light. Usually we meteorologists call this "ineffective sunshine" as although we have plenty of sun we have an Arctic air mass on top of us PLUS fresh snow pack that leads to a high albedo(the snow basically takes the sun's rays and reflects it back into the atmosphere). Highs will just be on either side of freezing. Now as high pressure pushes further to the east we'll get more of an east-to-southerly wind for Sunday as highs will jump into the lower and middle 40s with sunshine giving way to clouds in the afternoon in wake of our next system(which will be all rain so the snow pack shall be all history) pushing through late Sunday night into Monday morning. Overnight lows Sunday night will be rising through the 40s and into the middle 50s before falling down into the teens by Monday night ask more Arctic air filters in from the north.
This will lead to highs on Tuesday just into the middle teens with lows in the lower to middle single digits! Wednesday will be the transition day with highs in the upper 20s with high pressure settling offshore and then Thursday we'll be back in the lower and middle 40s in wake of our next system(which will also be rain Thursday night into Friday morning). At this moment behind that system we stay seasonable with highs in the lower 40s and overnight lows in the middle and upper 20s.
Until then enjoy your weekend(I'm not a fan of saying "stay warm" or "be careful outside with the dangerous driving conditions, etc.; you hear it everywhere else and why should I repeat it all? Besides, if you are reading this you are already intelligent enough and have plenty of common sense!) and of course you can check out the 7-day forecast any time at www.scottderekwx.com/forecast.html.