Storms, heat wave, outages: Americans gear up for flash flooding after weather dampens Fourth of July celebrations

The Fourth of July celebrations marking America's 250th anniversary were marred by deadly storms and a heat wave across large parts of the United States, leaving hundreds of thousands of utility customers without electricity. Forecasters have also warned that severe weather is expected to continue through the week.

Severe weather conditions dampen Fourth of July celebrations

CBS News on Sunday (local time) reported that millions of Americans across the Northeast experienced record-setting temperatures, while thunderstorms in the Midwest toppled trees, brought down power lines, and disrupted travel across several states.

In the capital city, Washington, D.C., thunderstorms compelled thousands to temporarily evacuate the National Mall, which was hosting the Freedom 250 Fourth of July celebrations, including US President Donald Trump's address, which was delayed by over an hour, and a massive fireworks show.

Attendees in the capital were asked to evacuate and seek shelter in buildings near the National Mall after the organisers delayed the commencement of the "Salute to America" events. In a statement, Freedom 250 spokesperson Danielle Alvarez said, "The safety of our guests, performers, and staff is our top priority. Due to approaching severe storms, Freedom 250, the United States Secret Service, the United States Park Police, the National Park Service, the Federal Emergency Management Agency, and all public safety partners are asking all guests to evacuate the event grounds and seek temporary shelter in a nearby building."

On Sunday, roughly 797,000 utility customers were left without power, with most outages being reported in Pennsylvania and Michigan, according to data from the utility tracking site PowerOutage.us.

New Jersey reported at least 25 suspected heat-related deaths, with the ages of those affected ranging from their mid-30s to their 80s. Both New Jersey and Atlantic City recorded their highest July temperature at 105 degrees.

The intense heat across the region helped in the development of severe storms, bringing wind gusts of up to 70 mph to areas including Perth Amboy, New Jersey. The weather disrupted rail services to New Jersey, causing cancellations and delays, while hundreds of trees were either damaged or uprooted.

Meanwhile, hundreds of utility workers from 12 states and Canada were deployed to Michigan on the afternoon of the Fourth of July to accelerate power restoration efforts, according to CBS Detroit.

Intense weather conditions also led multiple cities to cancel fireworks displays and reschedule them for later, along with canceling festival holidays.

34 million Americans under flood watch

The report said severe weather is forecast to persist throughout the week, with flood watches in effect for nearly 34 million residents across the Northeast until late Monday.

Between Monday and Tuesday, persistent heavy rainfall in the mid-Atlantic region could lead to flash flooding in the country's Northeastern urban areas. Some areas, such as New York City and Philadelphia, are likely to receive up to four inches of rain.

As a cold front pushes through the area, additional showers and thunderstorms are expected to persist across northern parts of the country and parts of the Great Basin, with strong to severe storms forecast from the mid-Atlantic through the northern Plains.

Additionally, scattered tornadoes are likely in the Plains, although the main threats will be wind gusts and hail.

Forecasters continue to monitor the evolving weather system as millions across the country remain at risk of further severe weather in the coming days.