Tonight’s NAM and GFS model data just rolling in…. an interesting weather possibility for Thursday just showing in both models.
A cold front moves through late Wednesday and low pressure develops on the front as it moves up along the coast. This might be our first real snowfall on Thursday. Amounts don’t appear too significant, maybe 3-4 1-3 inches.
This is a new development. Too early to be sure about details. I’ll keep an eye on it.
Wed 6PM: A quick update- latest models depict this low pressure system evolving further north; temps will likely be too warm for snow in the immediate PHL area.
A fast moving disturbance will bring rain about daybreak on Saturday. Much of the morning will be wet, but the rain stops early afternoon and clearing is expected by mid afternoon . High 49.
Christmas Eve will be dry and clear with lows in the mid 30s.
A zonal flow jet stream will keep temperatures above average for Sunday, Christmas Day and the next several days after. Sunday will be sunny and mild. High 51.
Look for things to become much colder and stormier next weekend, around New Year’s Eve.
Latest NAM FOUS data just became available. This will be mostly an ice storm rather than a snow event.
Temperatures in the upper atmosphere become too warm for snow before daybreak. Light snow starts after midnight but changes to sleet and freezing rain by daybreak in PHL.
Heavy freezing rain, likely with temperatures remaining near or below freezing at the surface, continues until late morning with a significant “cold air damming” effect. A significant ice storm is possible with heavy precipitation causing dynamic cooling, prolonging the freezing rain event.
Difficult travel during much of the morning, especially north and west of the city. Temperatures rise above freezing by the late morning or early afternoon as the precipitation tapers off.
