The baffling disappearance of Nancy Guthrie may have taken another dramatic turn after investigators were reportedly spotted searching the rugged desert landscape behind her Tucson-area home.

A neighbor living just a few doors away from the missing 84-year-old said she recently saw what appeared to be FBI personnel combing through thick brush in the Catalina Foothills — only days before the case reached the grim six-month mark.

The reported search comes after powerful monsoon storms battered the area, potentially shifting rocks, debris and even evidence that may have gone unnoticed during earlier searches.

Nancy, the mother of “Today” co-host Savannah Guthrie, is believed to have been forcibly abducted from her home during the early morning hours of Feb. 1.

She has not been seen since.

The neighbor told Fox News Digital that she recognized several faces from previous law enforcement operations connected to the case.

However, the Pima County Sheriff’s Department said no members of the official task force had recently returned to search the neighborhood. The FBI did not immediately comment, leaving fresh questions about exactly who was seen searching the area — and why.

Bob Krygier, a retired Pima County sheriff’s lieutenant and former SWAT commander, said there could be several explanations.

Investigators may have received a promising new tip pointing them toward a specific location, he said. They could also be revisiting previously searched terrain with a fresh set of eyes after six months of frustration.

“There’s a couple of different reasons that go through my mind,” Krygier said.

One possibility is that authorities received new information strong enough to send teams back into an area they had already examined.

Another possibility is the weather.

Tucson’s monsoon season began roughly a month ago, bringing sudden and violent downpours capable of dramatically reshaping the desert terrain.

“A lot of water has come down — a lot of water at once, and it pushes things,” Krygier explained. “So it’s moved the environment. Rocks have been pushed away.”

That means an object hidden beneath brush, mud or stones during earlier searches could now be exposed. At the same time, anything left near a wash could have been carried far from its original location.

Krygier said floodwaters in some parts of the region can rise from several inches to as much as 12 feet, generating enough power to sweep away vehicles, trees, boulders and people.

He described the rushing water as a massive “blender” filled with debris.

“There was a report of a man in the wash floating down, being pushed downstream by the water,” Krygier said, adding that the Santa Cruz River can reach between 20 and 30 feet deep and stretch 50 to 60 feet across during peak flooding.

“All that water, it’s rushing fast,” he continued. “It’s taken not only people, but it’s taken cars, it’s taken trees, branches, rocks.”

The possibility that the storms uncovered or relocated evidence is especially significant because washes and desert brush surround Nancy’s secluded neighborhood.

Authorities have previously searched the terrain near her home as part of the massive investigation into how an elderly woman could seemingly vanish from an upscale residential community without an immediate trace.

Pima County Sheriff Chris Nanos insisted last week that the investigation remains active and has not gone cold.

Detectives are reportedly continuing to pursue leads while reviewing “tens of thousands” of videos that could contain clues about Nancy’s disappearance or the movements of her suspected kidnappers.

The sheriff’s office also recently released two purported ransom notes in hopes that someone might recognize the writer’s unusual language or phrasing.

Investigators believe the sender’s “unique linguistic style” could ultimately help identify the person responsible.

Despite a combined reward exceeding $1.2 million, no one has claimed the money, and no arrest has been announced in connection with Nancy’s disappearance.

Anyone with information is urged to call 1-800-CALL-FBI. Anonymous tips can also be submitted by calling 520-88-CRIME.