We turn the page to October and the gradual transition of seasons continues. However, it's going to be a mild week and not very Fall-like despite the rather Fall-like weekend that we just experienced.
A large storm system in the southern U.S. will push northeast for the middle of the week, pulling moisture and warmth northward into the Delaware Valley. Showers and storms are possible for Tuesday afternoon into Wednesday as the system moves through. With a pretty significant surge of moisture coming north from the Gulf of Mexico, the prospect for heavier showers is in the forecast for some locations as this system moves in.
With the pull of warmth into the region, some 80 degree weather can't be ruled out on Wednesday afternoon before a cool front nudges through and brings us a bit closer to reality for Thursday and Friday. Both of those days look really nice, with temperatures in the 70s both afternoons. October does indeed start on a pretty mild note as the average high at this time of the year is drifting down towards 70 degrees.
However, a second cool front will push through at some point this weekend. There's some uncertainty on the timing of the front moving through: one of the big models we use suggests Saturday, the other suggests Sunday. I'm leaning towards Saturday for now, which would result in a cool Sunday with highs in the 60s. Right now, it does not seem like there will be much rain with the front but it will usher in a more pronounced taste of Fall.