Technical Discussion

Synopsis...

High pressure remains in control through early Thursday before storm system moves towards region from Midwest.  Few lake effect clouds/showers (esp. NW/NC) today due to cold air aloft and W'ly winds.  Rest of region will stay nice and sunny with temps near or just above seasonal levels in most places.  After rain Thursday evening/night Friday will cool down a bit before a pleasant Saturday.

Short Term (Tues-Wed night)...

A nice day in store for the Commonwealth with only a few scattered showers and clouds in northern zones due to lake effect.  Temperatures remain seasonable today and tomorrow nighttime lows in 40s and 50s with highs in the 60s and 70s.  Fairly quiet weather until Thursday.  Went with MOS as it seemed reasonable, especially given climatologically normal conditions.

Long Term (Thurs-Sat)

Low pressure moves into region during the day Thurs from Midwest.  Expect increasing clouds throughout the day with showers developing in the afternoon across western zones and evening in the east.  Although timing of system is fairly consistent between models, large discrepancies exist between GFS and other models.  GFS brings sfc low over central PA allowing for some overrunning precip associated with warm front.  Also keeps wave/system fairly flat leading to less of a pressure gradient and not much of a cool down on Friday.  WRF and CMC however are much more aggressive with the system and farther north.  This leaves PA in line for cold front precip (more convective and possibly more spotty).  Also, Friday is much cooler given these two models (esp. WRF which has temps in low 40s across W zones Fri morning).  Leaned toward the WRF/CMC solution for now but did not throw out GFS solution completely due to weak nature of precip events in the past month or two.  However, agreesive Pacific shortwave that will spawn the area of low pressure could very well lead to a stronger disturbance and the WRF/CMC model solution.  Definitely something to monitor is the coming days.  No matter what solution you believe, Saturday will be a great day with seasonable (or slightly below average) temps under sunny skies.

-Dan DePodwin