The last time we had a low below 20 degrees was one year ago tomorrow—Jan. 22, 2012. The last time we had a low below 15 degrees was also last year—Jan. 4, 2012. We will likely have at least two mornings this week with lows below 20 degrees, probably Wednesday and Thursday mornings. Our best chance for a low below 15 degrees will be Wednesday morning.
Temperatures like these are really not all that uncommon around here...it is January, after all. Just like we get temperatures 15 degrees above average on the 100-degree days in the summer, we also get temperatures 15 degrees below average on the 25-30 degree days in the winter. If you really think about it, highs in the 20s and lows in the teens is nothing compared to somewhere like Syracuse in upstate New York (where I spend most of my year at college...40 miles north of there, actually, in Oswego). I'm actually heading back there Wednesday, and I'll be waking up to below zero temperatures Thursday morning, so that is where the true "bitter cold" airmass is.
Today will be the warmest day of the week with a high in the mid 30s. We'll see a mix of sun and clouds and perhaps a few snow showers this afternoon. Tonight, as a disturbance moves through, some of us could receive a dusting of snow, so you may need to give yourself a little extra time to brush off the car on Tuesday morning.
Tuesday and Wednesday will be the coldest days of the week with highs in the mid 20s. On top of the cold temperatures will be the wind, creating wind chills of 10 to 15 degrees, so dressing in layers would be a good idea.
Thursday stays cold but with less wind. By Friday, I am watching a developing nor'easter that has the potential to give us some snow. It's much too early to provide any specifics, but be aware that you might need to shovel on Friday.
This weekend looks chilly but precipitation-free. Any snow that falls on Friday should slowly begin to melt by the second half of the weekend as temperatures rise a few notches above freezing.
Be sure to check in with Phillyweather.net throughout the week for updates on our potential nor'easter!