Over 1,300 flights in and out of the Northeast have been canceled as storms continued to batter the region over the weekend.
More than 1,320 flights into and out of the U.S. were canceled as of Sunday afternoon, with over 350 of those arriving and departing Newark Liberty International Airport, according to the online tracker FlightAware.
Severe weather prompted ground stops at John F. Kennedy and LaGuardia airports in New York and Newark Airport in New Jersey, according to the Federal Aviation Administration. Both airports announced on Twitter that they were experiencing flight disruptions due to weather conditions and encouraged travelers to check with their airlines before heading to the airport.
Thunderstorms and heavy rain battered the Northeast over the weekend, with the heaviest rainfall expected to target New York, New Jersey, Pennsylvania, Delaware and Maryland.
Flash floods in Bucks County, Pennsylvania, killed four people Saturday. Authorities were still searching for three people who disappeared after the floods, including a 9-month-old and a toddler.
The storm system also brought heavy rain to other parts of the Mid-Atlantic, including Virginia and West Virginia, according to the National Weather Service.
Flash flood warnings have been issued for parts of New York, including Queens and the Bronx, and Connecticut, including Danbury.
Significant river flooding is possible along New York's east coast, New Jersey and Delaware. Some of the highest rainfall totals recorded were 6 inches in Bay Shore, New York, and 4 inches in Danbury.
The National Weather Service also issued a tornado watch for parts of Connecticut, Maine, Massachusetts, New Hampshire, New York and Rhode Island on Sunday morning through 3 p.m. ET.
Hail up to half an inch in size and wind with gusts up to 60 mph are possible in the tornado watch area.
