2018 US fall forecast: Unseasonable warmth to grip Northeast; Extreme fire season predicted in West

It will be a gradual transition to fall for the Northeast and mid-Atlantic this year, as warmth lingers for both regions.

The Southeast will remain at risk for a tropical impact and flooding rainfall while the Southwest sizzles in scorching heat.

Meanwhile, the central and northern Plains will get a little bit of everything, including the threat for some early-season snow.

Gradual transition to fall in store for Northeast, mid-Atlantic and eastern Ohio Valley

A warm fall is predicted overall for the Northeast and mid-Atlantic as chilly air takes its time to arrive.

Warmth is set to linger across upstate New York, New England and the northern mid-Atlantic states, with nights cooling off before daytime highs start to drop.

"You can expect it to cool down the farther south and west you go due to precipitation," AccuWeather Expert Long-Range Forecaster Paul Pastelok said.

The mid-Atlantic, in particular, may be faced with tropical rainfall early in the season.

"There's been a lot of rainfall for the spring and summer, so if we do get any tropical impact, the risk of flash flooding will exist," Pastelok said.

While autumn may take longer than usual to arrive, it will be a picturesque season if forecasters are correct. Dry weather in the Northeast paired will cool nights will pave the way for vibrant leaves to emerge across the region.

Flash flooding possible as wet weather continues for the Southeast

The persistent wet pattern that occurred over the summer may continue into fall for the Southeast.

New Orleans, Louisiana; Birmingham, Alabama; Atlanta, Georgia; and Nashville and Chattanooga, Tennessee; are in the path to receive more rainfall after an already wet summer.

"I'd be watching for flash flooding in the area," Pastelok said.

Systems coming out of the southwest could create severe weather into October, he said.

Meanwhile, a transition to El Niño may mean a quieter hurricane season than originally predicted.

El Niño is a part of a routine climate pattern that occurs when sea surface temperatures in the tropical Pacific Ocean rise to above-normal levels for an extended period of time.

"We're definitely looking at a different season than last year," Pastelok said.

Two to three U.S. impacts are predicted, and forecasters will have their eyes on the southeastern Gulf heading into September.

'Bit of everything' in store from the western Ohio Valley to the central and northern Plains

From the western Ohio Valley to the central and northern Plains, forecasters predict there's a bit of everything on the cards.

Much of the northern Plains and Upper Midwest will have back-and-forth periods of wet and dry weather.

Temperature-wise, the season will start off warm before a blast of chilly air comes down from Canada.

This could lead to some early snow events.

Pastelok said, "If systems start coming out of the southwest, which we expect in mid- to late October, it could lead to some mixed rain and snow events across that area."

El Niño may send much-needed rainfall to the southern Plains

While much of the southern Plains will be enduring drought as the fall season begins, a reversal is in store.

El Niño typically strengthens the southern jet stream, which could increase rainfall in September or October, Pastelok said.

Depending on how strong the southern jet stream becomes, drought conditions could be dramatically lessened or even ended during the fall season.

The wet weather will also help to cool down the air after a rather warm start.

Summer to linger in the Southwest with some extreme temperatures predicted

Hot and dry conditions will grip the Southwest early in the season.

"There could be some extreme temperatures in September for the Desert Southwest from Phoenix on westward," Pastelok said.

These conditions will keep the threat for fires high before October brings a turnaround to cooler weather.

Meanwhile, dryness and dangerous fire conditions will continue for California.

"It looks like a really bad year for them," Pastelok said.

Northwest, Rockies to see turnaround to cooler weather by mid-season

As is typical, the Northwest and Rockies will endure hot conditions into the early fall.

Temperatures will be steamy, but they won't rival the summer of 2017.

Regardless, this will stoke the fire threat early on.

By mid-fall, a quick turnaround is predicted from hot weather to cooler air.

"You could be in hot and dry weather, then a week later, it could pretty cold with snow in the higher elevations," Pastelok said.

Ski areas will benefit from an early start to the season, he added.

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