Residents across the Philadelphia area face a dual weather hazard Tuesday as a heat advisory takes effect and severe thunderstorms are expected to develop by evening.
Temperatures are forecast to climb into the low 90s, with humidity pushing the heat index to around 98 to 100 degrees, according to CBS Philadelphia.
The heat advisory covers the urban corridor from noon to 8 p.m. Parents sending children to school should pack extra cold water. Some schools in the region are releasing students early because of the heat.
Storm Timing and Threats
NBC10 Philadelphia meteorologist Bill Henley reports a First Alert is in effect from 4 p.m. to midnight. Daytime hours bring only a passing shower risk, but the storm threat intensifies sharply through the evening.
The dangers include damaging wind gusts, hail, isolated tornadoes, and heavy downpours capable of triggering flash flooding.
Severe weather is not guaranteed for every neighborhood. Many areas will not see storms until after dark. Still, residents with evening plans this week should plan around potential disruptions. evening plans this week
Flooding Risk
Patch.com reported that in the most extreme scenarios, rainfall rates could reach 1 to 3 inches per hour where the heaviest storm cells set up. The National Weather Service noted that widespread flash flooding remains unlikely, but the localized threat is real.
Forecasters acknowledged relatively low confidence in the exact storm track because the system is fast-moving.
Low-lying streets and stressed drainage systems are the primary concern. The standard caution applies — do not drive through flooded roads.
Wednesday Through Thursday
NBC10 Philadelphia forecasts that Wednesday will stay mostly cloudy with temperatures in the low 80s and a chance of strong to severe afternoon storms.
Thursday brings another humid day with a high near 90 degrees and a heat index in the mid-90s, along with a further chance of isolated severe weather.
Relief Arrives for the Holiday Weekend
The stretch of unsettled weather is expected to break by Friday, according to CBS Philadelphia. A cold front clears the region and ushers in lower humidity.
Saturday should reach about 81 degrees under mostly sunny skies, with Sunday and Labor Day Monday sitting in the upper 70s to near 80 with comfortable conditions.