A strange split in the weather pattern is setting up across the United States this week, with the Northeast facing an unusually early nor’easter and a sharp burst of fall air while the desert Southwest deals with a growing flash-flood threat tied to deep tropical moisture.
Meteorologist Jonathan Kegges, host of the JustWeather YouTube channel, said the atmosphere is producing two very different hazards at the same time, with one storm system strengthening off the East Coast and another surge of moisture pushing into the Southwest from the Pacific.
“The first nor’easter of the season is expected to slam the Northeast,” Kegges said, adding that the system could also deliver the coldest air many areas have felt so far this season.
At the same time, he warned that flooding could remain a serious concern farther west as tropical moisture continues to stream north.
An Early Nor’easter Takes Shape
Kegges said one of the most unusual pieces of the pattern is the development of what he called a “very early season, very rare nor’easter.”
The system is expected to take shape between the Carolinas and Bermuda around Wednesday before moving northward.
A dip in the jet stream is helping the storm develop, while cool high pressure pushes south into the eastern third of the country.
That combination is expected to usher in a much more fall-like air mass.
Kegges said the storm should strengthen as it moves up the Eastern Seaboard, but the exact track remains uncertain.
That uncertainty matters because even a small shift toward the coast could greatly increase the impacts.
A track closer to shore would likely mean stronger winds, heavier rain, and a greater risk of coastal flooding along parts of the I-95 corridor and into New England.
If the system remains farther offshore, those impacts could be more limited.
That is one of the more interesting parts of this forecast because the basic storm looks increasingly likely, while the exact severity still depends on a track that has not fully locked in.
Coldest Air of the Season Pushes South
The nor’easter is also expected to drag a much cooler air mass southward.
Kegges said this should be the coldest air of the season so far for much of the East.
By Friday morning, he said places such as Pittsburgh and Syracuse could fall into the 40s, with Roanoke also dropping into that range.
He added that temperatures in the 60s could reach surprisingly far south over the weekend, potentially even into parts of Florida.
“I would not be surprised if we had 60s as far south as Orlando,” Kegges said, suggesting the cooler air could arrive by Saturday or, more likely, Sunday morning.
The Plains, however, may not see the same relief.
Kegges said Houston and San Antonio could still wake up to temperatures in the 70s and 80s because a strong upper-level ridge will keep hot air locked over much of the central and southern Plains.
That contrast makes the national weather map look almost split in two.
While the East gets its first real taste of fall, parts of the central United States may still feel more like summer.
Heavy Rain Could Target the I-95 Corridor
Rainfall is another major part of the nor’easter forecast.
Kegges said areas along the I-95 corridor could receive significant rainfall, with the strongest signal stretching toward Cape Cod and Boston.
Some forecast maps showed more than two to three inches in parts of the region.
The exact totals will depend heavily on how far west the storm tracks.
“If it wants to trend a little bit further to the west, that is where we’re going to have the problems,” Kegges said.
A westward shift could bring more rain inland, along with stronger winds and a greater coastal flooding threat.
The European ensemble guidance showed a wide spread in possible low-pressure positions, which Kegges used to illustrate how much uncertainty still remains.
Several different model members placed the storm at different points offshore, meaning forecasters still have some fine-tuning to do.
Still, the setup is worth watching closely because a relatively small movement could turn a manageable coastal system into a much more disruptive one.
Southwest Flood Threat Keeps Growing
While the East watches the nor’easter, the desert Southwest is dealing with a completely different danger.
Kegges said a dip in the jet stream over the West is pulling deep tropical moisture northward.
That moisture is expected to continue feeding into Arizona, New Mexico, West Texas, and areas near the Mexican border.
He said some locations could receive more than five inches of rain over the next seven days.
The flood threat could be enhanced further by moisture tied to a powerful hurricane moving near the Mexican coastline.
Kegges pointed to the Mexico, New Mexico, and Texas border region as one of the areas he is especially concerned about.
He also said Albuquerque and surrounding areas could face a decent chance of flash flooding.
“We know it doesn’t take much,” Kegges said, referring to how quickly normally dry terrain can flood when heavy rain falls in a short period of time.
That is especially important in desert areas, where hard ground and poor drainage can cause water to rise rapidly.
Pacific Hurricane Moisture Could Reach Texas
Kegges also spent time discussing a strong Pacific hurricane he identified as Polo.
Forecast guidance showed the system moving near the Baja Peninsula before potentially sending a large stream of moisture into the Southwest and southern Plains.
The Google DeepMind ensemble model showed some scenarios where that moisture continues north and east through Texas, New Mexico, and Arizona.
Kegges described it as a “big fire hose of moisture.”
He said that surge could become especially important late this weekend and into the early part of next week, around September 27 through September 29.
Even if the hurricane itself never reaches the United States as a tropical system, its leftover moisture could still produce heavy rain well inland.
That distinction is important because people sometimes focus only on whether the center of a hurricane makes landfall.
In this case, the moisture plume may matter just as much as the storm track itself.
Atlantic Remains Relatively Quiet
Kegges also gave an update on the Atlantic hurricane season.
He said conditions in the Gulf and Caribbean may become somewhat more favorable for tropical development, although wind shear still appears strong enough to limit many systems.
The Google DeepMind guidance showed only a weak signal in the western Gulf.
Kegges also mentioned that the nor’easter itself could potentially undergo a transition from non-tropical to tropical as it moves over the North Atlantic.
If that happens, the storm could eventually receive a name.
Elsewhere, he said the remnants of Fay remained in the Atlantic while another disturbance moved off the coast of Africa.
That disturbance could become a weak tropical depression or tropical wave near the Cabo Verde Islands, but Kegges said it was not expected to threaten the United States.
Fay, meanwhile, came close to reaching hurricane strength but fell just short.
Kegges said the storm peaked with winds around 70 mph, while hurricane status requires 75 mph.
That leaves the 2026 Atlantic season still waiting for its first hurricane.
Two Very Different Weather Stories at Once
Kegges’ forecast shows just how uneven the weather pattern is becoming across the country.
The Northeast is watching an early-season nor’easter and preparing for a strong push of cooler air, while the Southwest faces tropical moisture and a much more serious flood concern.
The central Plains, meanwhile, may remain under stubborn heat.
That combination is what makes this setup feel unusual.
It is not one nationwide storm or one simple cold front.
Instead, several pieces of the atmosphere are interacting at once, creating almost opposite weather problems in different regions.
Kegges said the biggest variables to watch in the coming days will be the exact track of the nor’easter, the amount of Pacific moisture reaching the Southwest, and how far south the cooler air manages to push.
For millions of people in the East, this week could finally feel like fall.
For parts of the Southwest, however, the more urgent concern will be how much rain falls and how quickly it arrives.
Mark grew up in the heart of Texas, where tornadoes and extreme weather were a part of life. His early experiences sparked a fascination with emergency preparedness and homesteading. A father of three, Mark is dedicated to teaching families how to be self-sufficient, with a focus on food storage, DIY projects, and energy independence. His writing empowers everyday people to take small steps toward greater self-reliance without feeling overwhelmed.
