Friday's heat index values will hover around 105 for Broward and Miami-Dade counties, but "feels like" temperatures could climb to as high as 111 degrees in parts of Southwest Florida. The heat advisory is in effect from 11 a.m. to 6 p.m.

The NWS Greenville-Spartanburg SC issued a heat advisory at 12:27 a.m. on Friday valid between 2 p.m. and 7 p.m. The advisory is for Mecklenburg, Cabarrus and Union counties.

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.

A heat advisory continues for parts of central Pennsylvania until 8 p.m. Thursday, with temperatures and humidity creating potentially dangerous conditions for residents. Isolated thunderstorms are possible this afternoon, particularly in southern counties, before a cold front brings relief and lower humidity.

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.