Tuesday wasn’t the nicest of days weather-wise, with abundant clouds that eventually produced some scattered showers and areas of drizzle as the day progressed. Nevertheless, it wasn’t a washout, and afternoon highs around 40 to 45 degrees were still above average for mid-January. Keep in mind, our average high for the first four weeks of winter should be in the mid to upper 30s, and we’ve only had two days this entire winter with a 30-something-degree high temperature.
Now there’s finally a long-lived cold snap in our future, one that will arrive late Thursday into Friday, set the stage for some snow to start the weekend, and one that will also stick around through most of next week as well. But before winter finally checks in for an extended stay, there’s still another mild day-and-a-half to enjoy first. So be sure to soak up some 50° highs on Wednesday before they check out for good, or at least for quite a while.
Get your Vitamin D here! This will be the pick day of the forecast in terms of warmth and sunshine, as a weak area of high pressure builds in and delivers a partly sunny, mild, and dry day. That's after we get rid of a little low level cloud cover or areas of fog in the morning. Highs will bounce back into the low to mid 50s for most (mid to upper 40s from the Poconos into northwestern New Jersey), likely the last 50-something-degree day we’ll see for quite a bit. But as many of us have seen upwards of 10 days with highs above 50 degrees so far this winter, there’s little room for complaint.
A cold front will sweep through the area and off the East Coast late Wednesday night and early Thursday morning. Out ahead of it, there’s nothing more than a shower or two. While a snow shower may linger behind it as well in the higher elevations, the more significant impact this front will have for everyone is to deliver our return to reality starting Thursday afternoon. So while highs on Thursday reach the mid to upper 40s, it’s likely early in the morning as temperatures begin to slowly fall in the afternoon as blustery northwest winds gust as high as 45 miles-per-hour and deliver some arctic air that will really make its presence felt by Thursday night and Friday.
Arctic high pressure over eastern Canada will give us plenty of sunshine and plenty of cold to wrap up the week, with highs on Friday only around 30 degrees despite lots of sun. A still brisk northwest breeze will keep wind chills colder and well below freezing throughout the day, but it won’t be as windy as Thursday was. Remember this cold air that’s in place come the weekend, as it’s one big ingredient for our impending Saturday storm.
All eyes are on Saturday for what could be the first accumulating snow of 2020. A light (for most) to moderate (higher elevations) snow is looking likely across much of the area north and west of Interstate 95, with the typical winter storm stereotypes in place. The farther north you travel and higher up in elevation you go, the more snow you will see, like the Poconos and northwestern New Jersey. The farther south and east you travel and closer to the coast you get, the changeover to rain occurs sooner and limits snow totals.
Right now, it looks like a period of snow will develop from late morning to early afternoon on Saturday from west to east across the area, a bit later than first thought. As a result, this shield of snow will be fighting the midday and afternoon sun angle, which is why snow accumulates less readily during the middle of the day than at night. Plus, the air will also be very dry initially so the snow will have to put up a fight just to reach the ground at the onset, which could also hinder accumulations.
Despite these obstacles, some accumulating snow is likely for most, with a C-2” more likely towards the Interstate 95 corridor, 2-4” towards the Interstate 78 corridor, and then more than 4” along the Interstate 80 corridor through the higher elevations.
Most of the snow looks to fall Saturday afternoon, with a change to sleet, freezing rain, and rain late in the day and through the overnight, especially from the Lehigh Valley south and east. Of course, timing and amount ideas can always change if the storm track or strength changes, so stay tuned as the week progresses. Cold, windy, and drier weather follows our storm for Sunday.