Slight pattern change won't bring widespread cooldown to Northeast
By
Alex Sosnowski, AccuWeather senior meteorologist
Updated Aug 27, 2021 2:29 PM EDT
Relief from prolonged heat and humidity will take hold across the Northeast this weekend, but as the transition takes place, there will be a renewed concern for flash flooding in some locations, AccuWeather forecasters warn.
Hot and humid conditions that expanded in the wake of Henri early this week have lingered in most areas into Friday. High temperatures ranging from the upper 80s to the middle 90s F, with AccuWeather RealFeel® Temperatures ranging from the 90s to low 100s have been common most of the week.
There are some changes coming to New England this weekend, but people in the mid-Atlantic hoping for a blast of cool, refreshing air similar to mid- to late-September and October will be greatly disappointed, according to AccuWeather Senior Meteorologist Brett Anderson.
It is tough for cold fronts to reach much of the Atlantic coast during August, and that will be the case in the coming days.
"For a front to roll through with a major change to cool weather, there needs to be a significant southward dip in the jet stream to help nudge the Bermuda High out of the way. Instead, the jet stream will barely have a ripple this weekend, so the air aloft will remain quite warm," Anderson explained.
There will be some cooling in the lower part of the atmosphere that will be assisted by the Atlantic Ocean.
Water temperatures are about their highest levels of the year right now, ranging from the 60s along the coast of Maine to the lower 80s along the Virginia capes.
"Any cooling by way of a northeasterly or easterly breeze will be limited and will tend to carry some moisture along with it," Anderson said.
Some reduction in humidity is likely for New England and part of upstate New York, but the humidity drop may become progressively less noticeable farther to the south and west this weekend, due to the ocean adding its moisture contribution to the air.
"It is possible for no significant change in humidity to occur from New York City on south and west this weekend," Anderson said.
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High temperatures are forecast to take a bit of a hit, especially in New England and northeastern New York state, where highs are forecast to trend downward to the 70s and even the upper 60s.
Some of the best weather this weekend in terms of low humidity sunshine, and fall-like conditions may be in Maine, closer to the source of the cool and dry air from eastern Canada. For example, high temperatures in Bangor, Maine, reached 91 on Thursday but are forecast to only reach the lower 70s on Saturday and the middle to upper 60s on Sunday. High temperatures at that level are more typical of late-September.
Farther to the south and west, the high temperature trend may only be 5-10 degrees lower from the extremes of much of this week. By Sunday, highs are forecast to range from the middle 80s in Pittsburgh and Philadelphia to just shy of 90 in Washington, D.C.
"Any time there is a flow of air partially or fully from the Atlantic, there can be issues due to cloud cover, lingering misty conditions and even patches of rain or thunderstorms. These are also concerns for this weekend in the mid-Atlantic, central Appalachians, Great Lakes and even New England," Anderson said.
During the summer, a change in air temperature, whether subtle or extreme, can also mean the risk of thunderstorm development.
"The atmosphere over the mid-Atlantic and central Appalachians is loaded with moisture and that can be squeezed out in the form of torrential downpours and the risk of flash flooding right through the weekend," Anderson said.
The greatest risk of flash flooding will extend through Saturday, as the storms on Sunday will be more spotty in nature.
"Motorists should be especially careful after dark as it may be difficult to see flooded roadways ahead of time," Anderson said.
Spotty storms with intense rainfall erupted over the mid-Atlantic region on Thursday afternoon. Over the course of one hour, 1.54 inches of rain, drenched Fredericksburg, Virginia.
"For those heading to the beach this weekend, in addition to the potential for stubborn clouds and even some rain, a stiff breeze from the Atlantic may lead to rough surf and strong rip currents from the southern New England coast to Long Island, New York, New Jersey and Delaware," Anderson added.
Another potential concern at the beaches is that runoff from Henri's flooding on Sunday and Monday may have washed pollutants into the surf zones. People are urged to abide by any local restrictions set forth by officials due to weather or contaminants.
During the middle and latter part of next week, it may be possible for a more substantial push of cooler and less humid air to reach the central Appalachians and mid-Atlantic coast. However, potential developments in the tropical Atlantic, including Ida heading for the Gulf of Mexico, may add some level of complexity to the forecast, should a system push northward into the Southern states.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, FuboTV, Philo, and Verizon Fios.
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News / Weather Forecasts
Slight pattern change won't bring widespread cooldown to Northeast
By Alex Sosnowski, AccuWeather senior meteorologist
Updated Aug 27, 2021 2:29 PM EDT
Relief from prolonged heat and humidity will take hold across the Northeast this weekend, but as the transition takes place, there will be a renewed concern for flash flooding in some locations, AccuWeather forecasters warn.
Hot and humid conditions that expanded in the wake of Henri early this week have lingered in most areas into Friday. High temperatures ranging from the upper 80s to the middle 90s F, with AccuWeather RealFeel® Temperatures ranging from the 90s to low 100s have been common most of the week.
There are some changes coming to New England this weekend, but people in the mid-Atlantic hoping for a blast of cool, refreshing air similar to mid- to late-September and October will be greatly disappointed, according to AccuWeather Senior Meteorologist Brett Anderson.
It is tough for cold fronts to reach much of the Atlantic coast during August, and that will be the case in the coming days.
"For a front to roll through with a major change to cool weather, there needs to be a significant southward dip in the jet stream to help nudge the Bermuda High out of the way. Instead, the jet stream will barely have a ripple this weekend, so the air aloft will remain quite warm," Anderson explained.
There will be some cooling in the lower part of the atmosphere that will be assisted by the Atlantic Ocean.
Water temperatures are about their highest levels of the year right now, ranging from the 60s along the coast of Maine to the lower 80s along the Virginia capes.
"Any cooling by way of a northeasterly or easterly breeze will be limited and will tend to carry some moisture along with it," Anderson said.
Some reduction in humidity is likely for New England and part of upstate New York, but the humidity drop may become progressively less noticeable farther to the south and west this weekend, due to the ocean adding its moisture contribution to the air.
"It is possible for no significant change in humidity to occur from New York City on south and west this weekend," Anderson said.
CLICK HERE FOR THE FREE ACCUWEATHER APP
High temperatures are forecast to take a bit of a hit, especially in New England and northeastern New York state, where highs are forecast to trend downward to the 70s and even the upper 60s.
Some of the best weather this weekend in terms of low humidity sunshine, and fall-like conditions may be in Maine, closer to the source of the cool and dry air from eastern Canada. For example, high temperatures in Bangor, Maine, reached 91 on Thursday but are forecast to only reach the lower 70s on Saturday and the middle to upper 60s on Sunday. High temperatures at that level are more typical of late-September.
Farther to the south and west, the high temperature trend may only be 5-10 degrees lower from the extremes of much of this week. By Sunday, highs are forecast to range from the middle 80s in Pittsburgh and Philadelphia to just shy of 90 in Washington, D.C.
"Any time there is a flow of air partially or fully from the Atlantic, there can be issues due to cloud cover, lingering misty conditions and even patches of rain or thunderstorms. These are also concerns for this weekend in the mid-Atlantic, central Appalachians, Great Lakes and even New England," Anderson said.
During the summer, a change in air temperature, whether subtle or extreme, can also mean the risk of thunderstorm development.
"The atmosphere over the mid-Atlantic and central Appalachians is loaded with moisture and that can be squeezed out in the form of torrential downpours and the risk of flash flooding right through the weekend," Anderson said.
The greatest risk of flash flooding will extend through Saturday, as the storms on Sunday will be more spotty in nature.
"Motorists should be especially careful after dark as it may be difficult to see flooded roadways ahead of time," Anderson said.
Spotty storms with intense rainfall erupted over the mid-Atlantic region on Thursday afternoon. Over the course of one hour, 1.54 inches of rain, drenched Fredericksburg, Virginia.
"For those heading to the beach this weekend, in addition to the potential for stubborn clouds and even some rain, a stiff breeze from the Atlantic may lead to rough surf and strong rip currents from the southern New England coast to Long Island, New York, New Jersey and Delaware," Anderson added.
Another potential concern at the beaches is that runoff from Henri's flooding on Sunday and Monday may have washed pollutants into the surf zones. People are urged to abide by any local restrictions set forth by officials due to weather or contaminants.
During the middle and latter part of next week, it may be possible for a more substantial push of cooler and less humid air to reach the central Appalachians and mid-Atlantic coast. However, potential developments in the tropical Atlantic, including Ida heading for the Gulf of Mexico, may add some level of complexity to the forecast, should a system push northward into the Southern states.
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Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier, Spectrum, FuboTV, Philo, and Verizon Fios.
Report a Typo