us weather heat flood threat july 12 2021
New York braces for a fllash flood threat as the Western heat eases
02:35 - Source: CNN
CNN  — 

The Northeast is bracing for more heavy rain Monday after severe storms last week inundated New York City subways and submerged streets.

The region then took a hit from Tropical Storm Elsa, enduring even more rainfall.

A weak storm system will slowly bend southward Monday and Tuesday, carrying storms along the Northeast coast and bringing another threat for significant flooding.

“It appears the heaviest rainfall will likely be across eastern Pennsylvania and eastward towards the greater New York metro area, where some patchy 1 to 3 inch totals are possible through Wednesday morning,” the Weather Prediction Center said.

Flash flood watches have been issued by the National Weather Service from northern New Jersey up through the southern edge of Maine, including for New York and Boston.

Some watches are in place through Tuesday and Wednesday as the rain is expected to be slow-moving.

“Heavy rain in a short period of time may cause streams and creeks to rise quickly and top their banks. There is also the potential for flash flooding across more urbanized areas and those areas with poor drainage,” said the weather service in Mount Holly, New Jersey.

Flood watches span the Northeast through midweek.

The prediction center has issued a moderate risk for heavy rainfall Monday over the tri-state area of New York, New Jersey and Connecticut due to two rounds of rainfall bringing extensive flooding threats.

Heavy rain will fall on soils that are already saturated from previous rainfall in the last week, leading to more runoff and higher flood risk.

Monday evening holds the greatest flooding concern in thetri-state area, due to thunderstorms moving across the region dumping from 2 to 5 inches of rain.

Rainfall the past week from Elsa was 300% or higher than the average according to the WPC, and scenes of New York subways filled nearly to the brim with floodwater as pedestrians wade through in trash bags, attempting to stay dry are not out of the question once again.

Up to 5 inches of rainfall is possible in some areas of the Northeast through Wednesday.

The month-to-date rain total in New York is already 4.8 inches for the month, compared to the 1.5-inch average for the month-to-date July rainfall. That is a record for the highest amount of rainfall recorded so far in July.

Boston is included in a slight risk for excessive rainfall and could see almost 2 inches of rainfall in some areas.

It has already been a wet July for the city with rainfall this month making it the fifth-wettest July on record.

The month-to-date rainfall in Boston has reached a record 7.6 inches after seeing rain every day since the beginning of the month. The average month-to-date rainfall for the area is 1.2 inches.

By Wednesday the low-pressure system will push a warm front northward and leave drier weather behind for the Northeast. The dry period won’t last for long though – as the end of the week could bring even more rain to the drenched region.