SUNDAY: A front separating a much drier air mass over upstate New York from the humid air over our region lies near the N.Y. border. The proximity of the front will spark a few thundershowers, though about half the region will remain dry.
A band of thunderstorms is firing north of the city in the pre-dawn hours as a weak jet stream disturbance passes over the aforementioned front. These storms will bring downpours to those traveling into Southeast Pennsylvania and New Jersey.
Additional t-storms will pop up across the area Saturday afternoon as the sun destabilizes the atmosphere. Otherwise, we can expect a mix of sun and clouds.
The most likely place to receive a cooling p.m. thundershower will be over the higher ground north and west of the city.
Temperatures will peak in the upper 80s. Any evening thundershowers should end by midnight, with partly cloudy and mild conditions expected. Patchy fog will form in the humid air.
MONDAY: On Memorial Day, high pressure off the Atlantic Coast will direct sultry air over the region on breezes from the southwest. Temperatures will soar to near 90, with the exception of the shore and along the Bay. A cooling thundershower could erupt in the heat of the day in a few places.