Philadelphia August 26, 2018 6:47 pm NBC10 First Alert Weather: Heat Wave Begins Monday Another heat wave is set to begin in our region Monday. NBC10 First Alert Weather meteorologist Steve Sosna has the forecast. US & World Videos 2:44 Cloudy, chance for rain this weekend 2:41 The weekend kicks off with mostly cloudy skies and passing showers 2:31 Back to cooler temperatures 2:36 Back to spring temperatures 3:09 Departure from hot weather with cloudy conditions and cooler temps