5 days ago
Flood watch in effect for Philadelphia region as heat, humidity and storms make comeback
We knew it wouldn't last. The somewhat cooler and drier start to the week is over, and the muggy air is now making a not-so-subtle return.
High pressure over the western Atlantic, what we call the "Bermuda High," is pulling warmer, stickier air into our region today. Dew points will climb into the low to mid 70s, and with afternoon highs in the upper 80s to low 90s, it will feel more like the upper 90s.
No heat advisory is in effect, but the combination of warmth and humidity will make it feel noticeably uncomfortable compared to the past week.
A cold front pushing in from the west will be the trigger for late-day and evening showers and thunderstorms. The setup favors slow-moving storms, meaning heavy downpours could quickly lead to localized flash flooding.
The Storm Prediction Center has us in a marginal risk for severe weather, while the Weather Prediction Center flags the area for possible excessive rainfall. Damaging winds are possible, but flooding is the main concern.
The National Weather Service has issued a flood watch from 2 p.m. until 1 a.m. for most of the CBS News Philadelphia coverage area through late Wednesday night.
The watch includes Philadelphia, Delaware and parts of Chester and Montgomery counties in Pennsylvania, Camden, Gloucester, Mercer, Middlesex, Salem, Somerset and parts of Burlington counties in New Jersey and New Castle County in Delaware.
The front won't fully clear right away. It's expected to stall nearby Thursday. This means clouds will hang around, and scattered showers or storms could pop up again during the day.
Temperatures will still be warm, topping out in the mid to upper 80s, though the humidity will stay high.
By Friday, the system will finally drift offshore, and high pressure from the north will start to move in. That will help lower humidity levels, especially north and west of the city, but it will still be seasonably hot with highs near 90 degrees.
The comfortable stretch is over, at least for now. We're in for a classic August combo: heat, humidity and the chance for drenching thunderstorms, before things dial back just a touch heading into the weekend.
