As several disturbances ride along the northern edge of a heat dome anchored over the Central Mississippi Valley, a stormy stretch will take shape across the Northeast, Mid-Atlantic, and Great Lakes, including the increased threat of severe storms capable of destructive winds, large hail, and perhaps a tornado or two.

Storms could bring down trees and power lines, while flash flooding will become increasingly likely, especially in urban areas where runoff occurs easily.

As of right now, there are four consecutive days of at least a Level 2 out of 5 severe storm threat for portions of the region. 

This is likely the first time areas like Philadelphia have been under a Level 2 out of 5 storm threat for three consecutive days in September since 2023. 

The last occurrence in 2023 was the only other time, along with a stretch in 2008, where a span of severe weather days had occurred, making this a rather rare stretch for some, the FOX Forecast Center said.

The multiday severe weather event kicks off on Tuesday and carries through to Friday.

Tuesday

The initial setup begins Tuesday afternoon as a weak disturbance moves over New York, New Jersey, and Connecticut into southern New England.

Storm energy will greatly increase throughout the day, which will support organized storms capable of damaging winds, severe hail, and perhaps a couple of tornadoes.

A second, more pronounced disturbance will dive around the top of the heat dome late Tuesday night, with storms originating around the Great Lakes during the day expected to merge into a storm complex that tracks southeast toward the Mid-Atlantic coast. 

As this complex sweeps through, damaging wind gusts and hail will remain the primary hazards, particularly across central and southern Pennsylvania into Wednesday morning.

Wednesday

According to the FOX Forecast Center, scattered thunderstorms may already be underway across Pennsylvania and points southeast early Wednesday. 

As clouds and morning storms begin to break up, enough heating should develop through the afternoon to create a warm, humid, and increasingly unstable atmosphere, and with a more potent upper-level disturbance moving across the region, it will provide the support needed for storms to re-organize.

The main threats will be damaging wind gusts and large hail, although a couple of tornadoes will also be possible in the strongest storms. 

“This will likely be the day with the most damaging wind reports and potential loss of power,” the FOX Forecast Center said.

Additionally, a Level 2 out of 4 flash flood threat has been issued for Wednesday, which includes New York City.

Thursday and Friday

On Thursday, the heat dome to the south will continue to strengthen and shift back west, while more dips in the jet stream will deepen along the East Coast, creating a more favorable pattern for severe thunderstorms across the Mid-Atlantic and eventually the Carolinas. 

In addition, numerous record high temperatures will be possible in the exact areas expecting storms.

Thursday’s severe threats shift slightly farther south in the Mid-Atlantic, encompassing Washington, D.C. Storms may develop near the Delmarva or areas farther west along boundaries left behind by earlier storms. 

“All the ingredients from the previous two days will come back into play as we head into Labor Day Weekend,” the FOX Forecast Center noted. 

Come Friday, another round of severe storms is likely as the dip in the jet stream strengthens further across the East Coast. The focus may shift into the southern Mid-Atlantic states, where damaging wind gusts would be the primary concern yet again.

By Saturday, some severe potential could linger farther south across the Carolinas before the pattern breaks down.