Today's forecast is one of relatively high confidence in generality but low confidence in terms of specifics in your backyard in the city. An active storm complex is currently (as of 4 AM) in Western Ohio and Western Pennsylvania, pushing east and southeast towards us. This complex of storms may weaken some as it approaches but the threat for heavy rain and thunder will exist. Ahead of it, scattered areas of thunder are around to the north and northeast of a warm front boundary that extends roughly from Pittsburgh to Philadelphia at this hour.
This warm front is the boundary of weather war today -- north of the front, heavy rain is the larger impact with a lesser consideration of severe weather. South of the warm front, severe weather odds are higher.
The morning thunderstorm complex moves through, with the stuff in Western PA hitting us between 8 and 10 AM with a morning round of rain and thunderstorms, more numerous north of the city than south. There will probably be a break in the activity for the city and south, with continuing rain and thunder north, for midday and the early afternoon hours. More thunderstorms will develop this afternoon, especially south of the city, with the threat for severe weather increasing in Delaware and Maryland as we work towards dinner.
North of the city, rainfall is the big story with a couple of inches of rain likely. South, less rain but a better chance of damaging thunderstorms in the mid/late afternoon hours. In the city, as the warm front generally gets to about Philadelphia this afternoon before the low/disturbance responsible for all of this gets to us, some heavy rains later this morning and a thunder chance in the afternoon but the severe risk is not as robust as further south.
Needless to say, a fun day ahead.
Highs today range from the 60's in Allentown to near 90 in Dover (south of the warm front). There will be a pretty marked temperature spread from 30 miles south of the warm front to 20 miles north, on the order of 15-20 degrees this afternoon. It wouldn't shock to see Wilmington at 85 and Quakertown just above 70 at some point this afternoon. For the city, we're thinking just shy of 80 although the warm front may graze north enough to get the Airport and Center City north of 80.