Flooding, tornado risks return to the Northeast 1 week after Ida

After Tropical Rainstorm Ida tore through the Northeast last week causing historic flooding and unleashing destructive tornadoes, a new severe weather threat is expected across the rain-weary region into Wednesday night.

At least 50 deaths were blamed on the former hurricane from Connecticut to Virginia, according to The Associated Press, as it unleashed torrential rainfall that inundated basement apartments in New York City, caused homes to collapse in New Jersey and put a major highway underwater in Philadelphia. Recovery and clean-up efforts in those areas could be impeded by the midweek storms.

"A ridge of high pressure provided the region with some very nice weather on Tuesday; however, [forecasters] are expecting a cold front to produce showers and heavier thunderstorms in the eastern third of the country on Wednesday," said AccuWeather Senior Meteorologist Carl Babinski.

"Most of these thunderstorms are expected from the end of the day Wednesday to the first part of Wednesday night in the big cities and near the coast," Babinski said.

Cities in the path of these storms include Montreal, Quebec, Albany and New York City, New York, Philadelphia and Washington, D.C. The entirety of Vermont and New Jersey could also experience severe weather.

More than 65 million are facing some type of severe weather risk into Wednesday night, according to the National Weather Service's Storm Prediction Center.

"We've already seen this boundary trigger multiple strong thunderstorms in the Great Lakes region," explained Babinski. There was one tornado reported Tuesday, in Kendall County, Illinois, outside of Chicago and several reports of damaging wind gusts and hail across the Midwest.

Among numerous other reports, 4.5-inch hail was measured to the north-northeast of Appleton, Wisconsin, and trees were reported damaged and uprooted near Winter, Wisconsin.

The Storm Prediction Center has over 21 million people under a "slight" risk area, which is the fourth-highest risk category, one level above "marginal." To compare, on September 1, Philadelphia, Baltimore and Washington, D.C., were all under an enhanced risk due to Ida, which is one level above a slight risk.

Like on Sept. 1, tornadoes are an expected threat across parts of the Atlantic coast on Wednesday. This time, tornadoes could reach farther north to around Albany.

"We'll need to keep a watchful eye on this aspect of the weather into Wednesday night," said Babinski.

Another weather impact residents of the Northeast aren't keen on seeing again soon is flooding. Not only is there a risk for flash flooding with the storms ahead of this cold front, but forecasters also anticipate hail and damaging winds, with some gusts forecast to reach an AccuWeather Local StormMax™ of 75 mph.

"With so much of central and northern New Jersey, southeastern New York and eastern Pennsylvania left saturated by the torrential rain associated with Ida last week, the current flood guidance implies that all it would take to renew these flooding problems is for 0.50 to 1 inch [of rain] within a period of three hours or less," said Babinski.

The flooding problems triggered by Ida were a primary cause for the high number of fatalities across the Northeast last week. Several families perished from inescapable rising floodwaters while sheltering in basements.

Since Aug. 1, New York City has recorded more than 300% of the city's average rainfall, while Boston and Washington, D.C., have had over 200% of their average rainfall. This will allow flooding to occur more easily in these locations.

This image, captured early Wednesday morning, shows the flash flood watch in effect for parts of the mid-Atlantic on Wednesday and Thursday. (AccuWeather/NWS)

Flash flood watches are already in effect across parts of eastern Pennsylvania, southern New York and northern New Jersey, including Allentown, Pennsylvania, and Trenton, New Jersey.

Babinski said he expects that the heaviest rainfall is most likely to occur between 8 p.m. Wednesday and 2 a.m. Thursday.

CLICK HERE FOR THE FREE ACCUWEATHER APP

"[AccuWeather's] outlook for rainfall totals in much of the region is suggesting a general 0.25 to 0.50 of an inch will fall, but locally higher amounts of 1 inch or more can cause flooding, especially Wednesday night," said Babinski.

Drier air will return across the Northeast's interior on Thursday, but downpours and localized urban flooding problems will linger across parts of New England and Long Island, New York, during much of the day and across southern New Jersey and the Delmarva Peninsula for a time in the morning.

Dry weather is on tap for most of the Northeast starting Thursday night into Friday, when high pressure makes a comeback to the region. However, forecasters urge residents to use caution before rushing to the beach this weekend.

"Some very nice weather is expected Friday through Sunday, but Hurricane Larry in the Atlantic Ocean is anticipated to pass to the east of Bermuda this week and produce large swells, resulting in rough surf and strong rip currents along East Coast beaches," warned Babinski.

For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.