By Lauren Casey

PHILADELPHIA (CBS) — Plan for a witch’s stew of weather on Halloween with rain, lightning, wicked winds and a dramatic temperature drop. A potent storm system is set to impact the Delaware Valley on Thursday into late Thursday night.

The daytime hours will feature rounds of rain as the system’s warm front crosses the region. Expect temperatures to surge into the 70s on the backside of the front, resulting in the warmest Halloween in Philadelphia in 15 years — with a forecast high of 74 degrees.

(Credit: CBS3)

Temperatures will remain in the 70s into the nighttime hours and trick-or-treaters have a shot at keeping their costumes dry as a lull in the rain appears likely during the evening, most likely after 6 p.m. and until the cold front arrives, when things get a bit batty.

(Credit: CBS3)

Expect a round of heavy rain with embedded thunderstorms possible after midnight. Passage of this strong cold front will be very apparent with widespread wind gusts of 50-plus mph. Localized power outages may occur and definitely bring in those outdoor decorations prior.

(Credit: CBS3)

With the intense winds comes a fast and dramatic temperature drop, potentially from 70s to 50s in less than one hour, likely to occur between 1 a.m. and 4 a.m. Friday, from west to east.

Temperatures may bottom out in the upper 40s by Friday morning’s commute. Eeeek! Any lingering rain wraps up for most by then.