Severe thunderstorms are forecast to impact millions of residents across the Northeast and Mid-Atlantic regions, including major cities along the I-95 corridor, for four consecutive days starting Tuesday. The storms bring the threat of destructive winds, large hail, and the possibility of isolated tornadoes.
This prolonged period of severe weather is considered rare for September. Philadelphia, for instance, has not experienced three consecutive days of at least a Level 2 out of 5 severe storm threat in September since 2023, with similar occurrences only noted in 2008. The FOX Forecast Center noted that this pattern marks a significant event for the region.
The multiday severe weather event begins Tuesday afternoon as a weak disturbance moves across New York, New Jersey, Connecticut, and southern New England. Storm energy is expected to increase throughout the day, fostering organized storms capable of producing damaging winds and severe hail. Late Tuesday night, a more significant disturbance is predicted to move around a heat dome positioned over the Central Mississippi Valley, potentially merging with storms originating from the Great Lakes into a complex that will track southeast toward the Mid-Atlantic coast. Damaging wind gusts and hail are expected to be the primary hazards as this system moves through Pennsylvania and into Wednesday morning.
By Wednesday, scattered thunderstorms may already be occurring in parts of Pennsylvania and points southeast. As the morning storms clear and the atmosphere warms and humidifies, an increasingly unstable environment is expected. A potent upper-level disturbance moving across the region will support the re-organization of storms, with damaging wind gusts and large hail being the main threats. The FOX Forecast Center anticipates that Wednesday could be the day with the most damaging wind reports and potential power outages. A Level 2 out of 4 flash flood threat has also been issued for Wednesday, including New York City.
The severe weather pattern is expected to continue through Thursday and Friday. On Thursday, the heat dome to the south is forecast to strengthen and shift westward, while jet stream dips along the East Coast will enhance the conditions for severe thunderstorms across the Mid-Atlantic and potentially the Carolinas. Record high temperatures are also possible in the areas expecting storms. The focus for Thursday's severe threats may shift slightly south, affecting Washington, D.C., and areas along the Delmarva Peninsula.
As the Labor Day weekend approaches, the ingredients for severe storms are expected to persist. Friday could bring another round of severe weather, with the focus shifting to the southern Mid-Atlantic states, where damaging wind gusts are anticipated to be the primary concern. By Saturday, the potential for severe storms may extend farther south into the Carolinas before the atmospheric pattern begins to break down.