PHILADELPHIA (CBS) — Buckle up for a wild weather ride this week as temperatures surge to near-record levels, followed by the increasing threat for accumulating snow just 12 hours later.
Our week started off on a great note Monday, with temperatures around 15 degrees above average and lots of sunshine. And while you won’t need the heavy coat for the next two days, keep it handy. By Thursday, winter will remind us that it’s not going anywhere just yet.
We are tracking two separate systems this week. The first arrives early Tuesday in the form of scattered showers, which could lead to the risk for icing in the Poconos and higher elevations of Northampton county.
This system doesn’t have a ton of moisture with it, but will produce pockets of steady rain through the mid-morning and early afternoon hours across the area, with the most rain (around .25″) occurring in the north and west suburbs and just a few scattered showers to the south of Philadelphia. We’ll also have to be on alert for dense fog as temperatures will stay mild – near 60 for highs in the city.
This system departs and we get a few bonus hours of spring-like warmth on Wednesday as the sun peeks out and temperatures soar into the 60’s. Our record in Philadelphia is 63, and there’s a good chance we get very close, if not tie or break that record on Wednesday. But late Wednesday night, that all changes as a second storm forms off to our south. This will coincide nicely with a surge of cold air from the north and west, and the system will rapidly intensify overnight Wednesday into Thursday morning, leading to a quick changeover to snow.
There are many things to watch with this system. First, temperatures will be very warm in the days preceding the system, so the ground (especially the roads) will be warm. This could cause some initial melting upon changeover. However, if the snow falls heavily enough, as it looks like it will, once you get a layer of snow it can pile up quickly. Another limiting factor will be temperature. The storm is arriving at the coldest part of the day – overnight into the early morning – but after highs in the 60’s the preceding day, it will be hard to get temps to really drop quickly below the freezing mark.
So, you’re looking at temperatures around or above 32 during the duration of the snowfall. Again, that’s not to say it can’t happen – as long as the air aloft is cold enough and the precipitation rates are high, snow can and will accumulate, though it will be a pasty wet snow with high water content that won’t fluff up as much.
As of now, it’s looking likely that much of our area, especially the city on north, could pick up several inches of wet snow overnight Wednesday into Thursday morning, leading to the potential for a slushy commute and possibly even school delays in spots if it pans out the way it looks now. That said, the setup has to be perfect on the heels of this warmth to get significant snowfall, so it’s an evolving forecast and one we’ll continue to work on over the next 24-36 hours.
Make sure you stay tuned!