After a beautiful New Year’s Day with mostly clear skies and high temperatures 7 to 10 degrees above normal, changes moved in overnight.
A low pressure system to the south developed and moved in overnight, bringing us widespread precipitation. The associated front is a warm front, and it will lift northward as the low develops.
The National Weather Service issued a freezing rain advisory for Monday morning for New Jersey (except Cape May County) through Philly, Montgomery, Chester, Delaware, and Bucks Counties, starting at 4 a.m. until 8 a.m.
Due to the potential for early partially clear skies and minimal wind leading to significant radiational cooling away from the coastline, there will be areas to the north and west where temperatures will fall near the freezing mark, but as models indicate, this seems to be more precautionary for the metro and areas south and east.
Be on the lookout for untreated surface areas in the early morning hours, but I don't see this being an issue after 9 a.m. Locations near the water will benefit from a slight onshore flow which will gradually be shifting around to the southeast, bringing slightly warmer temperatures in from the ocean. This would explain why Cape May County is not under the Advisory.
The RAP model has cooler solution for the freezing rain, while the RDPS and HRRR have temperatures warmer across the region. Either way, we’re issuing a First Alert, focusing on the early morning commute.
Apart from that, the next story is the widespread rain, which could bring us half an inch to just over 1 inch of rain by Tuesday. Then we track a cool down, a major cool down for the rest of the week. I'm still keeping Wednesday at 50 degrees and watching the reinforcing cold front that will sweep through by Wednesday. As the Polar Jet dips down, temperatures will be at or below freezing by the end of the week into the weekend.