This pattern will continue for tomorrow with highs expected in the 50's. But the jetstream will begin to dive south by Wednesday and those mild southerly winds will be replaced by cold northwest winds with wind chills near zero. A coastal low will develop Thursday off the Carolinas. This will move moisture north into this cold air and set the stage for the possibility of some snow by Thursday Night. The question is just how close the storm tracks along the coast.
Most raindrops begin as ice crystals high in the clouds.
They develop at altitudes where the temperatures are below freezing. When ice crystals collide, they form snowflakes. As these snow flakes fall through lower layers of the atmosphere they encounter warmer air and melt into raindrops. Late tonight after midnight, colder air will begin to work it's way into the region. This may allow for a brief changeover to snow showers in the Lehigh valley before the rain moves out and colder air moves in with strong gusty winds.