In the 500 mb pattern, we currently have a bit of a ridge building over the east as our Canadian high pressure has shifted east off the coast and we have a trough/cold front to the west leading to now more of a southwest wind developing, this will help to keep some mild air in the forecast for the next 2 days with temperatures near to slightly above average, this is not a very powerful ridge thanks to the -NAO developing so no real big impressive warm up is expected ahead of the next cool down
So temperatures both today and tomorrow will be in the mid to upper 70s for most of the area, lower 70s in the higher elevations and perhaps some urban areas such as Philadelphia or Newark NJ hit 80, low temperatures will be in the lower 50s NE PA, mid to upper 50s elsewhere tonight , lows will be warmer tomorrow night as clouds and rain are expected so mid 50s for NE PA , upper 50s to mid 60s elsewhere for lows
On Saturday night a potent cold front will slowly come through the area
The potential for heavy , significant rainfall is high with this cold front as an area of low pressure develops along it over the Tennessee River Valley and moves north and east , no severe weather is expected but rain/weak thunderstorms will begin tomorrow evening west and gradually move east through the area through Sunday morning/early afternoon , there could be some localized flash flooding.
The good news is for next week the storm threat we advertised for Monday-Wednesday looks to be a non-threat now as a powerful NAO block should keep it well to the south and east of the area so cool but dry and tranquil weather can be expected early/mid-week as Canadian high pressure and another trough takes hold with highs generally in the mid 60s to mid 70s Sunday through Thursday and lows returning to the 40s for most, lower to mid 50s , over southern and eastern portions of the forecast area and some 30s for NW portions and higher elevations, another stretch of below average days.
As a trough dips into the western US later next week and weekend there could be a fairly significant warm up in the east depending on if the NAO block holds or if it shifts east before that trough swings east bound a few days later but generally temperatures are expected to be near to below average through the period.