Monday Evening Technical Discussion

Synopsis:

                A cold Arctic air mass has overspread the state and will continue to provide cold air for the next few days. Lake effect snow showers should continue for northwest portions of the state with a couple more feet possible over the next two days. Expect a weak clipper to move north of the region Wednesday afternoon, allowing for some light snow in northern Pennsylvania. A stronger system should move through on Friday possibly providing a moderate to heavy snowfall for the state.

Short Term: Tue-Thu

                Cold air has overtaken the state of Pennsylvania as an Arctic front passed through the state on Monday. The northwest breeze and warm lakes have created lake effect snow for northwestern Pennsylvania where as much as 15" has fallen by Monday evening. Models show the lake effect continuing through Tuesday with a much as 2' of additional snow possible. The models also show extreme cold moving into the state with surface temperatures stuck in single digits and teens, while 850mb temperatures fall below -10^oF. Breezy northwest winds will lead to wind chills below zero at times. This is a true Arctic air mass that Jack Frost has sent down to the state of Pennsylvania. A weak clipper system should push north of the state on Wednesday bringing a touch of light snow to northern Pennsylvania. Cloud will move back in later Thursday ahead of our next system for Friday.

Long Term: Fri-Sun

                Yet another snowstorm will be pushing through the state on Friday. A clipper dropping in from Canada will phase with energy in the south to provide a storm for the mid-Atlantic. Models are in disagreement of the timing as the NAM brings the snow as early as 12z Friday and the EURO/GFS hold off until around 18z Friday. The models also disagree with the precipitation amounts as the NAM gives much of the state 0.5"+ of liquid precipitation. The GFS/EURO are much drier with an average of 0.25"-0.5" liquid across the state. The EURO/GFS is favored at this time as the NAM is in its long range right now and seems to be phasing the northern and southern branches of the jet stream too late. One thing that the models are agreeing on is that temperatures will remain cool in the teens to lower twenties. This will allow for higher than normal snowfall ratios of possibly 20:1. Once the storm passes through, high pressure will move in and provide a reinforcing shot of cold air for the weekend.

Zachary Fasnacht