Philadelphia May 23, 2019 4:48 am First Alert Weather: Tracking Severe Thunderstorms NBC10 First Alert Weather meteorologist Bill Henley is tracking the potential for severe storms Thursday. A First Alert will be in effect this afternoon. US & World Videos 2:36 Back to spring temperatures 3:09 Departure from hot weather with cloudy conditions and cooler temps 3:04 Seasonable temperatures return to end the week 2:44 One last warm, sunny day before changes this weekend 2:22 Another warm day as high temps flirt with record