A heat advisory is in place across the Northeast, from Maryland to Maine, where residents are bracing for temperatures 5 to 15 degrees above average. The heat index -- what the temperature feels like with humidity -- could reach 103 degrees in Philadelphia on Wednesday and Thursday.

Lehigh and Northampton counties, as well as neighboring Bucks and Berks counties, will be under a heat advisory from 10 a.m. until 8 p.m. In the Lehigh Valley, a high of 92 is expected, but forecasters said it will feel closer to 102.

Thursday: A slight chance of showers and thunderstorms, mainly between 4 and 5 p.m. Mostly cloudy, then gradually becoming sunny, with a high near 93. Heat index values as high as 102. West wind 5 to 10 mph. Chance of precipitation is 20%.

On Wednesday at 1:59 p.m. an updated heat advisory was released by the National Weather Service in effect until Thursday at 10 p.m. for Passaic, Hudson, Bergen, Essex and Union counties.

The advisory is in effect until 8 p.m. Seek cool shelter: Opt for an air-conditioned room to stay comfortable. Avoid direct sun exposure: Protect yourself and check on vulnerable relatives and neighbors.

A heat advisory is in effect for the New York City area Wednesday and Thursday, with feels-like temperatures expected to exceed 100 degrees as more storms threaten the forecast. Air quality is also a concern for vulnerable groups.

A Heat Advisory is in effect for portions of inland Northeast Florida until 6 p.m. WATCH THE FORECAST \| DOWNLOAD THE APPS. The First Alert Weather Team says this is the first heat