Summer and fall to play tug-of-war in northeastern US into late September
By Alex Sosnowski, AccuWeather senior meteorologist
September 20, 2018, 2:53:53 PM EDT
The northeastern United States will be in the middle of an atmospheric battle zone into the end of September as waves of cool air begin to push out of Canada and tropical air fights back.
Cool air has been building across central Canada over the past week and is forecast to bulge southward at times in the coming days.
The pattern for the next couple of weeks or so will translate to long stretches of dry weather, but there is still the potential for some days with drenching rain ahead.
It is the type of pattern that may require shorts and short sleeves in the afternoons, long sleeves and jackets on certain nights and even rain gear once in a while.
Shots of cooler, less humid air to follow Florence
Following Florence's flooding rainfall, dry air has settled into part of the Northeast.
The vast majority of the region can expect rain-free weather through Friday morning with lower humidity and noticeably cooler nights, when compared to much of the month so far.
However, the tug-of-war between warm air and cool air will just be getting started.
Warmth and humidity are forecast to surge on Friday ahead of another push of cool air into the first part of the weekend.
The leading edge of the cool air may be accompanied by showers and locally heavy thunderstorms centered on late Friday and Friday night.
Temperatures will climb well into the 70s to the middle 80s on Friday, before temperatures are then slashed by Saturday.
"The most pronounced cooling this weekend will be from New England to the upper part of the mid-Atlantic, central Appalachians and eastern Great Lakes," according to AccuWeather Lead Long-Range Meteorologist Paul Pastelok.
"Nighttime temperatures will dip to the chilly middle 30s to lower 40s across the northern tier [of this region] during Friday and Saturday nights," Pastelok said.
Along with the occasional cool days will come the risk of widespread late-night and early-morning fog. The fog is likely to be common in the river valleys, but it can occur anywhere the sky is mostly clear and winds are calm at night.
'There is still more of hurricane season to go': Expert warns another tropical threat may make US landfall
By the numbers: Florence's devastating blow to the Carolinas
'Why didn’t you evacuate?': Expert explains why fleeing Florence’s wrath wasn’t a privilege everyone could afford
Volunteers, charities help victims to rebound from Hurricane Florence so they don't have to 'face this tragedy alone'
Rising floodwaters, potential dam failures threaten North Carolina communities in Florence’s wake
The boundary separating the cool air across the north and steamy air to the south is likely to stall over part of the Ohio Valley and southern Virginia this weekend.
"As a storm moves eastward along that boundary, rain may spoil the second half of the weekend in the central Appalachians and mid-Atlantic," Pastelok said.
Another cycle of warmth followed by a major cooldown is likely to follow next week with rain in the offing during the transition.
Additional tropical threats, temperatures during early autumn may depend on strength of Bermuda high
"Later this month, the cooldowns are likely to be more robust over the North Central states with more of a tendency to push to the Atlantic coast," Pastelok said.
There is a chance that a persistent Bermuda high pressure area may flex its muscle once again and delay or mitigate that major widespread Atlantic coast cooldown.
It was a very strong Bermuda high that created tropical conditions during early September and allowed Florence to reach the Carolina coast this past Friday.
Such a pattern may allow another tropical feature to move up from the Caribbean and drift near the Atlantic coast around the start of October before much cooler air punches through.
Even with the waves of cool air en route to the Northeast, as temperatures are tallied for the entire month, September is likely to be one of the warmest on record for the Northeast, according to AccuWeather Senior Meteorologist Brett Anderson.
Warm and muggy nights during the first two weeks have probably tilted the scale so much that the cool shots forecast during the second half of the month are not likely to erase the overall warmth.
Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.
More Weather News
Weather News - December 13, 2018, 1:48:54 PM EST
Thanks to a quick response and around-the-clock work, road repair crews completed their work in just a few days.
Weather News - December 13, 2018, 2:04:41 PM EST
Owen continues to strengthen and is on track to make a second landfall in northern Queensland with flooding rain and destructive winds at the start of the weekend.
Weather News - December 13, 2018, 12:28:55 PM EST
The recent calm and chilly spell in the United Kingdom will come to a screeching halt this weekend as a potent storm unloads blizzard conditions, soaking rain and strong winds.
Weather News - December 13, 2018, 2:12:38 PM EST
Large storms and cold air are likely to take a break over much of the nation during much of next week ahead of the Christmas holiday.
Weather News - December 13, 2018, 8:40:06 AM EST
The volcanic area west of Naples, Italy, is stirring with early signs of a new caldera cycle for one of the world's most menacing supervolcanoes, according to new research.
Weather News - December 13, 2018, 8:08:04 AM EST
A newly formed depression in the Bay of Bengal is expected to develop into a tropical cyclone in the next 48 hours and threaten parts of eastern India this weekend.