Northeast: Soggy start to the week, but pattern change on the way

Although the start of the week will remain under a damp regime for some Northeast and New England locations, forecasters say that a dry and cooler pattern is on the way for some interior regions later this week.

The repeating downpours and pockets of potent thunderstorms that have developed and tracked over the Northeastern U.S. late last week and this weekend will persist into midweek.

"What is left of a stalled boundary that has been parked over much of the region will linger a bit longer. That means showers and thunderstorms will develop once again as a weak area of low pressure tries to develop off of Long Island and southern New England," explained AccuWeather Senior Meteorologist Matt Benz.

A new front approaching from the Midwest will lead to an eruption of showers and thunderstorms that will push eastward from Tuesday to Wednesday even as the storm offshore departs

Very humid air will linger across much of the Northeast through Tuesday. Coastal areas are likely to remain sticky through Wednesday.

Less humid air will begin to creep into the Ohio Valley ahead of a storm tracking over the Great Lakes region, but this will quickly be disrupted on Tuesday as a cold front associated with this storm brings rounds of rain and thunderstorms to the region.

"There may not be much of a break from the wet weather as a zone of low pressure advances eastward from the Great Lakes into Tuesday. Showers and thunderstorms will break out once again with this feature across the region on Tuesday with heavy rain possible into Wednesday, especially across portions of New England," stated Benz.

The swath of storms can stretch from parts of the Ohio Valley, mid-Atlantic and New England states on Tuesday before advancing to the coast on Wednesday. Some storms that develop in this zone from early in the week to midweek will be able to pack a punch with respect to rainfall totals.

"The moisture content of the atmosphere will remain very high, especially for this time of the year, across much of the Northeast with moisture levels more akin to July-like levels. That means any thunderstorm will be an efficient producer of rainfall which can lead to flooding for any location that sees prolonged downpours," noted Benz.

Anywhere from 1-2 inches of rain can occur from the mid-Atlantic states to New England during the first half of the week, with locally higher totals possible in the strongest storms. AccuWeather meteorologists warn that under the right atmospheric conditions, this pattern could even produce locally severe thunderstorms.

Late last week and over the weekend, the weather pattern prompted numerous travel delays across the Northeast, particularly for the main hub of New York City airports. Storms prompted ground stops, extensive flight delays and cancellations, which can continue to cascade into the days to come. Additional storms that track across the region into the start of the week can result in additional delays or cancellations, and it is recommended that travelers in the area stay up to date on any potential travel plan changes through at least midweek.

Even though many locations along the Northeast coast will continue to see storms on Wednesday, areas from the Great Lakes stretching to the interior Northeast will begin to notice a pattern of cooler and drier weather take over. A wide zone of high pressure will gradually nudge southward from Canada and play a large role in the weather to come late week and into the weekend.

Residents across the mid-Atlantic states on through New England can notice a dip in humidity levels by the second half the week, dropping from dew points ranging upwards of 60-65 degrees Fahrenheit to nearly half of that.

Temperatures are expected to fall between 5-10 degrees F in most areas by midweek compared to early week, and this cooling trend will even bring values below the historical average for mid-September for places like Columbus, Ohio, Pittsburgh, and Syracuse, New York.

For many, this pattern change bringing clear skies, dry conditions and lower temperatures will feel like autumn weather has truly arrived. Especially after the noticeably warm start to the month, conditions by late week will give residents the chance to finally break out their fall flannels and maybe even visit a pumpkin patch.


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"A cold front will finally deliver a more seasonable air mass to much of the eastern U.S. Thursday and this front may play a hand in where Lee ends up later this week and into next weekend," explained Benz.

By Friday, the weather across much of the interior Northeast will be primed for those attending outdoor activities such as evening high school football games or picnics. Closer to the coast, however, will be a different story as Hurricane Lee churns northward parallel to the Eastern Seaboard.

Benz added that this cold front may help to steer the tropical system away from the East Coast of the US, but it's all about timing. If the front can capture Lee, much of the U.S. may be spared direct impacts from the storm, but if Lee misses the front, it can swing farther west.

Rough seas and strong rip currents can spread along the East Coast as Lee tracks northward toward eastern New England and Atlantic Canada by the end of the week and the weekend. Based on the current track of Lee, gusty winds are expected to spread from coastal Massachusetts on northward to areas of Newfoundland and Labrador by the coming weekend.

Rainfall totals can range from 1-2 inches across a large swath of Nova Scotia, eastern New Brunswick, southwestern Newfoundland and even far eastern Maine, while a zone of 2-4 inches of rain is possible in central and southwest Nova Scotia from Hurricane Lee. The highest totals from Lee are expected to be within a zone of 4-8 inches of rain, located mainly to the west of Halifax, Nova Scotia.

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