We’re officially heading into a heat wave, with Philadelphia in for another hot and humid day Saturday. Saturday we can expect 91 degrees and the chance for scattered afternoon and evening thunderstorms, some packing heavy rain and gusty winds. We are two out of five on our severe weather r isk scale with timing expected between 3 and 7 p.m. Sunday is drier but still as hot and humid. Our heat wave will continue until Tuesday. Next week, we will see temperatures returning seasonable with slightly lower humidity. ...read more read less