Rounds of rain to usher in cooler conditions across East Coast
By
Courtney Travis, AccuWeather senior meteorologist
Published Sep 27, 2020 3:53 PM EDT
A change in the weather pattern this week will not only bring an area of wet weather into the Northeast, but also usher cooler air into the region.
A dry pattern has remained in place across much of the Northeast for most of September, and much longer for some locations.
Into Monday, "portions of Maine, New Hampshire, Massachusetts, Connecticut and Rhode Island were in an extreme drought, while much of New England to central Pennsylvania were in severe drought," said AccuWeather Meteorologist Ryan Adamson.
The storm bringing in the wet weather will originate in the center of the country. A huge dip in the jet stream will send that rain to the Eastern Seaboard as well as deliver a drastic cooldown in the Midwest.
With the jet stream diving so far south, this storm will be able to tap into some tropical moisture from the Gulf of Mexico and the Gulf Stream off the Atlantic Coast of the Southeast.
Rain will progress slowly from west to east into Tuesday night, with rain likely to continue across eastern New England on Wednesday.
"The heaviest rain, which could occur in two areas, is likely to bring an average of 2-4 inches with locally higher amounts," according to AccuWeather Senior Meteorologist Alex Sosnowski.
One swath of drenching rain set up over the Appalachians, while a second batch was developing along the Interstate 95 corridor in the mid-Atlantic on Tuesday afternoon.
Forecasters say motorists should anticipate travel delays, and people with outdoor plans may need to have indoor alternatives planned through the middle of the week.
In addition to the downpours, thunderstorms that erupt along and ahead of the leading edge of cooler air can be locally gusty.
"The greatest risk of thunderstorms with isolated damaging winds gusts will generally be just east of New York City later Tuesday night to early Wednesday," according to AccuWeather Senior Meteorologist Dave Dombek.
Any wind that accompanies the wet weather could also lead to additional early leaf drop, affecting the foliage later this fall. Motorists and pedestrians are advised use caution in wooded areas where leaves are coming down. The rain can make paved surfaces rather slippery.
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Several rounds of rain could be beneficial to parts of the region, helping ease some of the drought distress. However, rainfall is likely to be heavy enough for flooding to become a concern.
"Any urban area in the I-95 zone from the Carolinas to Maine could be susceptible to flooding in this pattern, while the greatest risk of small stream flooding will be in areas where heavy rain has occurred in recent weeks, such as from North Carolina to eastern Virginia," Sosnowski said.
"The ground in New England should draw in most of the rainfall like a sponge," Sosnowski added.
A second round of rain may develop over part of the mid-Atlantic and central Appalachians areas late Thursday, then lift northeastward during Friday.
Across the mid-Atlantic and southern Appalachians, some rivers are just now starting to recede following the heavy, tropical rainfall from Beta. Additional rainfall could cause water levels to rise or slow the rate of recession.
As the wet weather pulls northward into Canada, a new air mass will move into the Northeast in its place. This air mass will bring much cooler air. After the steady rain moves away, spotty showers are forecast, mainly around the Great Lakes and the Appalachians.
"As the calendar turns to October on Thursday, locations like the Adirondacks of upstate New York as well as some high ground in northwestern Pennsylvania and the Laurel Highlands may not make it out of the 50s F," Adamson said.
By Friday, afternoon high temperatures in the 50s will be even more widespread across the interior Northeast, while places east of the Appalachians remain in the 60s.
Although a drastic change from the warmth experienced early this week, temperatures are expected to be right around normal or a few degrees lower than normal for this time of year.
"The core of the coldest air will remain in the Midwest late this week, but temperatures only in the 60s are forecast to extend as far south as Raleigh and Atlanta," added Adamson.
Chilly air and mostly dry conditions are likely to stick around in the Northeast into the weekend.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo
News / Weather Forecasts
Rounds of rain to usher in cooler conditions across East Coast
By Courtney Travis, AccuWeather senior meteorologist
Published Sep 27, 2020 3:53 PM EDT
A change in the weather pattern this week will not only bring an area of wet weather into the Northeast, but also usher cooler air into the region.
A dry pattern has remained in place across much of the Northeast for most of September, and much longer for some locations.
Into Monday, "portions of Maine, New Hampshire, Massachusetts, Connecticut and Rhode Island were in an extreme drought, while much of New England to central Pennsylvania were in severe drought," said AccuWeather Meteorologist Ryan Adamson.
The storm bringing in the wet weather will originate in the center of the country. A huge dip in the jet stream will send that rain to the Eastern Seaboard as well as deliver a drastic cooldown in the Midwest.
With the jet stream diving so far south, this storm will be able to tap into some tropical moisture from the Gulf of Mexico and the Gulf Stream off the Atlantic Coast of the Southeast.
Rain will progress slowly from west to east into Tuesday night, with rain likely to continue across eastern New England on Wednesday.
"The heaviest rain, which could occur in two areas, is likely to bring an average of 2-4 inches with locally higher amounts," according to AccuWeather Senior Meteorologist Alex Sosnowski.
One swath of drenching rain set up over the Appalachians, while a second batch was developing along the Interstate 95 corridor in the mid-Atlantic on Tuesday afternoon.
Forecasters say motorists should anticipate travel delays, and people with outdoor plans may need to have indoor alternatives planned through the middle of the week.
In addition to the downpours, thunderstorms that erupt along and ahead of the leading edge of cooler air can be locally gusty.
"The greatest risk of thunderstorms with isolated damaging winds gusts will generally be just east of New York City later Tuesday night to early Wednesday," according to AccuWeather Senior Meteorologist Dave Dombek.
Any wind that accompanies the wet weather could also lead to additional early leaf drop, affecting the foliage later this fall. Motorists and pedestrians are advised use caution in wooded areas where leaves are coming down. The rain can make paved surfaces rather slippery.
CLICK HERE FOR THE FREE ACCUWEATHER APP
Several rounds of rain could be beneficial to parts of the region, helping ease some of the drought distress. However, rainfall is likely to be heavy enough for flooding to become a concern.
"Any urban area in the I-95 zone from the Carolinas to Maine could be susceptible to flooding in this pattern, while the greatest risk of small stream flooding will be in areas where heavy rain has occurred in recent weeks, such as from North Carolina to eastern Virginia," Sosnowski said.
"The ground in New England should draw in most of the rainfall like a sponge," Sosnowski added.
A second round of rain may develop over part of the mid-Atlantic and central Appalachians areas late Thursday, then lift northeastward during Friday.
Across the mid-Atlantic and southern Appalachians, some rivers are just now starting to recede following the heavy, tropical rainfall from Beta. Additional rainfall could cause water levels to rise or slow the rate of recession.
Related:
As the wet weather pulls northward into Canada, a new air mass will move into the Northeast in its place. This air mass will bring much cooler air. After the steady rain moves away, spotty showers are forecast, mainly around the Great Lakes and the Appalachians.
"As the calendar turns to October on Thursday, locations like the Adirondacks of upstate New York as well as some high ground in northwestern Pennsylvania and the Laurel Highlands may not make it out of the 50s F," Adamson said.
By Friday, afternoon high temperatures in the 50s will be even more widespread across the interior Northeast, while places east of the Appalachians remain in the 60s.
Although a drastic change from the warmth experienced early this week, temperatures are expected to be right around normal or a few degrees lower than normal for this time of year.
"The core of the coldest air will remain in the Midwest late this week, but temperatures only in the 60s are forecast to extend as far south as Raleigh and Atlanta," added Adamson.
Chilly air and mostly dry conditions are likely to stick around in the Northeast into the weekend.
Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Report a Typo