... There is a chance for a shower or thunderstorm with the passage of a weak front tomorrow, mainly south and east of Pittsburgh, but most of the region will remain dry for the bulk of the weekend. Temperatures will remain above average through the weekend.
NEAR TERM /THROUGH SATURDAY/... No changes needed for the evening update...
Surface high will maintain its influence overnight though an increase in mid-low level moisture should keep temperatures slightly elevated, which should keep lows in the upper 50s/low 60's.
Ridge will continue to migrate west and build as an upper troughs drop south over New England. A weak cold front will drop south-southwestward toward the upper Ohio Valley on Saturday, though the bulk of the forcing will be focused north and east of the forecast area. Still, marginal instability and moisture, and the help of terrain for additional lift, will support some shower and thunderstorm activity across the region. Coverage looks to be best south and east of Pittsburgh, which is where both the synoptic and mesoscale models highlight precipitation chances. QPF should be rather minimal across the region given coverage.
SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... Mainly dry conditions are expected Sunday and Monday as subsidence resumes. Height falls and weak cold advection should allow for temperatures to moderate closer to seasonal normals.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... The central CONUS ridge is progged remain parked and become less broad as the upper level trough deepens further over the northeast as the jet core rounds the base. This with lower heights and temperatures aloft, will result in a downward trend in temperatures...below normal by mid-week. The cooler temperatures aloft and periodic shortwaves could also result in spotty rain showers, mainly during the afternoon with diurnal heating. Latest NBM probs show no greater than a 20% probability of greater than 0.10" during any 24hr period next week....around 10% for 0.25"