What to KnowA hot and humid Tuesday will give way to the threat of severe storms across Philadelphia and the surrounding region with damaging winds, hail, isolated tornadoes and flash flooding all possible.A First Alert is in effect from 4 p.m. to midnight Tuesday, Sept. 1 with the greatest threat f or severe weather arriving late in the afternoon and especially during the evening.The unsettled weather continues Wednesday, which is expected to be mostly cloudy, warm and humid. A First Alert is in effect from 4 p.m. to midnight Tuesday, Sept. 1 with the greatest threat for severe weather arriving late in the afternoon and especially during the evening. Follow along below for live updates. Get the latest weather updates by downloading the NBC10 app and following the NBC10 First Alert Weather team. ...read more read less