PHILADELPHIA (CBS) — The Philadelphia area is under a heat advisory until 8 p.m. Saturday as the area enters its fourth heatwave since the beginning of June. A flash flood watch will be in effect from Saturday afternoon until 2 a.m. Sunday due to the risk of storms.

There will be dangerous heat once again Saturday with highs in the mid-90s and a heat index feels-like over 100. The high will be 96.

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Afternoon and evening thunderstorms will develop ahead of a cold front approaching from the west. Some of these storms could turn severe with wind and flooding the primary threats.

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Torrential downpours are expected with any storms and localized flooding is possible during the evening.

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Scattered showers remain on Sunday, but it will also be a cooler and less humid day in the mid 80’s following the passing of the front. The high will be 87.