Powerful thunderstorms and severe weather conditions are expected to impact the Northeast and other parts of the United States ahead of the Fourth of July holiday. The storms, which include damaging winds and flash flooding, are causing travel disruptions, particularly at major airports in the Northeast such as Philadelphia International Airport, where a ground stop has been implemented. Travelers in Florida, Washington, D.C., New York, and Pennsylvania are advised to check flight statuses due to delays and potential cancellations. Authorities have also issued warnings about beach safety, with some popular beaches across the country potentially closing due to harmful bacteria and hazardous conditions like rip currents. The weather is anticipated to affect millions of people celebrating Independence Day, with officials urging caution and preparedness for the severe weather expected throughout the holiday weekend.