Philadelphia June 28, 2018 11:48 pm NBC10 First Alert Weather: Heat Wave Begins Thursday The heat wave begins Thursday. NBC10 First Alert Weather chief meteorologist Tammie Souza lets us know how long it will last. US & World Videos 2:55 Warmer summer-like temperatures return for Tuesday 3:19 Keep your rain boots handy, rain chances everyday this week 2:44 Gray, warmer Monday 2:24 Gray Monday 2:00 Dreary Monday weather