Technical Discussion

Synopsis

Lake effect snow showers will continue across the Northwestern portions of the state Wednesday before coming to an end early Thursday due to the approach of a high pressure system. Expect dry conditions on Thursday before a clipper system moves in from the west on Friday, providing some light snow later Friday evening and overnight. Expect temperatures to warm up a few degrees Friday and Saturday as the high pressure slides to our east. Skies will clear Saturday before a larger storm approaches the region early on Sunday.

Short Term (Wed-Early Thursday)   

The retrograding low pressure providing the northwest winds over the past few days, will lift into northern Canada tomorrow switching our winds more WNW and leading to weaker lake effect snow showers on Wednesday. Temperatures remaining well below average Wednesday across the state with the winds from the northwest advecting in cold air. As the low pressure moves away a high pressure system will begin to push into the region from the south later on Wednesday. The high pressure will lead to weaker winds on Thursday ending any lake effect snow showers by midday Thursday.

Mid Term (Thur-Sat)

High pressure will lead to dry conditions on Thursday and Thursday night. The high pressure slides east on Friday providing some warm air advection early Friday before a clipper system moves in later Friday leading to light snows across northern Pennsylvania Friday evening. Skies will clear behind the clipper on Saturday as high pressure remains just east of the region. A southerly flow on Saturday will provide more warm air advection on Saturday bringing temperatures closer to average. Saturday will be "the calm before the storm".

Long Term (Sat Night-Sun)

A low pressure system will move up from the Mississippi Valley later Saturday increasing cloud cover overnight Saturday. This storm will move into the region on Sunday but the models are conflicting on whether the storm will move to our west or east. A more westerly track would lead to mainly rain with some mixing with snow possibly across western Pennsylvania, while an eastern track would lead to rain in eastern portions of the state and snow from Central Pennsylvania west. At this point leaning with a western track, but future model runs will hopefully lead to more confidence. Cold air advection will reestablish itself behind the storm leading to cooler conditions and some more lake effect snow early next week.

Zach Fasnacht