We have a very active pattern developing today, and will remain in place through Monday along with rather chilly temperatures after today
Today, a cold front is slowly dropping south, and with it will come a SW wind with pretty warm temperatures, with highs in the lower 70s interior to mid to upper 70s along the coast.
It will also bring increasing cloud cover and the threat for scattered showers as we head into the afternoon and evening hours. The front will drop south of the area overnight tonight, letting a much cooler air mass into the region for tomorrow through next week. Lows tonight will be in the mid 50s to around 60 with dropping humidity
Late this afternoon/evening
However, the frontal boundary will not continue dropping south but instead will stall over Southern PA , southern NJ and Maryland/Delaware. Meanwhile, as seen on the radar above, there are disturbances riding this front , these disturbances will lead to a raw, chilly and wet Friday-Sunday time period
Thursday, isolated to scattered showers will be possible as a very weak disturbance rides this front through the area, most likely in the morning and then agin late at night, but overall a relatively nice day (especially compared to how Friday through Sunday will be) is expected with cloudy to partly sunny skies and highs in the low 60s NE PA to around 70 along the coast. Lows will fall into the lower to mid 40s NE PA to low 50s along the coast.
By the overnight hours Thursday and Friday morning, a MUCH stronger disturbance will be moving in , showers are expected to fill in by Friday morning and a steady rain is likely from Friday afternoon through Saturday afternoon, this disturbance will be a very slow mover as we are in a “split flow pattern” where the sub tropical jet is well south of the area and the polar jet will be well north of the area, so there’s not much wind aloft to push this by quickly
The exact track and thus exact location of heaviest rain will depend on exactly where this front stalls but the area will be up anywhere from 1-3 inches of rain through the forecast period, most of which will fall Friday and Saturday. Latest models suggest the heaviest rain will fall from Allentown through Long Island including Northern NJ but I will be watching over the next 36-48 hours.
Highs Friday through Sunday will only be in the mid to upper 50s NE PA to low to mid 60s along the coast with lows in the mid 40s to low 50s
More weak disturbances will move through the area Sunday and Monday, leading to cloudy skies, easterly winds cool temperatures and the threat for scattered showers, before Canadian high pressure drops south and pushes this frontal boundary south
Tuesday and Wednesday the polar air mass will remain in place with highs in the upper 50s to low 60s NE PA to mid to upper 60s along the coast before a slight moderation begins by Thursday.