1 dead as heavy rain prompts flash flood emergency in parts of New York state

Heavy rain from the Mid-Atlantic into the Northeast prompted flash flood alerts in parts of New York state Sunday.

A flash flood warning and a flash flood emergency were both issued in the lower Hudson Valley, New York, by the National Weather Service.

Southeastern Orange, western Putnam, Rockland and northern Westchester counties continue under flash flood warnings through 12:15 a.m. Monday, meteorologists said. Thunderstorms are impacting the area, which has already seen 5 to 8 inches of rainfall.

County Executive Steve Neuhaus declared a state of emergency in Orange County, New York, due to Sunday's storms.

Neuhaus later confirmed the drowning death of a woman in her mid-30s he said was trying to leave her house with her dog when she got swept up. Officials are trying to rescue a number of people trapped on U.S. Route 9W, Neuhaus said.

New York Gov. Kathy Hochul declared states of emergency in both Ontario and Orange counties late Sunday night.

Over the next few hours, rain showers and thunderstorms will continue to make their way east to New York City, according to the National Weather Service's New York division.

As the storm system slowly moves through the northeast Sunday and throughout the day Monday, there is a concern for catastrophic flooding in parts of New England, according to meteorologists.

The Weather Prediction Center, a division of the National Weather Service, issued a rare high-risk warning for excessive rainfall for Monday in Vermont and parts of New York. These areas could see up to 5 inches of rain through Tuesday.

The already-soaked ground could lead to major flooding, especially in the morning hours.

Parts of New York, Pennsylvania, Connecticut, Vermont, New Jersey and Maryland are under a flood watch, with impacted areas seeing a possible 1 to 2 inches of rainfall per hour through Monday, according to experts.

There has already been significant flooding in the area. Norfolk, Connecticut, has issued an emergency declaration after several roads and bridges were washed out in the northwestern Connecticut town.

Extreme weather is impacting other parts of the country, as 37 million Americans are on alert for dangerous heat.

The National Weather Service issued dangerous heat alerts Sunday for residents from the Pacific Northwest to the deserts in the Southwest -- even stretching east toward the Florida Panhandle.

Phoenix has reached at least 110 degrees for nine consecutive days, with the pattern of scorching temperatures expected to continue for another week, meteorologists said.

El Paso, Texas, has set a record for the longest streak of consecutive days above 100 degrees, with Sunday marking the 24th day in a row with a temperature in the triple digits. The city broke a record on Saturday after reaching 108 degrees, exceeding 107, set in 1951.

Regions worldwide have been experiencing extreme heat in recent days, leading to the hottest temperatures ever recorded on the planet.

Earth warmed to the highest temperature ever recorded by human-created tools when the average global temperature reached 17.18 degrees Celsius, or 62.92 degrees Fahrenheit, on the Fourth of July.

ABC News' Julia Jacobo and Kenton Gewecke contributed to this report.