LITTLE ROCK, Ark. (AP) – Wind and hail whipped a small retirement community during a recent storm, but despite witness reports that a funnel cloud was moving along a highway and just “took out” a McDonald’s restaurant, there was no tornado raking the landscape.

Forecasters spent the next 20 minutes checking what proved to be a hoax, shelving their other work concerning a storm system producing violent weather elsewhere.

“If the office hadn’t stayed focused on the entire picture, there’s a chance we might have misevaluated another storm in that system,” said Steve Piltz, the meteorologist in charge of the National Weather Service at Tulsa, Okla., which provides forecasts and warnings for northwestern Arkansas.

Weather hoaxes are rare, so forecasters are alarmed by two recent deliberate false reports in less than a week. Diverting attention can make them miss real storms, putting the public at peril. The matter is serious enough that the FBI and U.S. attorney’s office are investigating.

“It could be disrupting government operations,” said Steve Frazier, an FBI spokesman in Little Rock. “Obviously if the person did it as a threat, or to cause a panic, it could be a violation by using the telephone to do it.”

A trained volunteer storm spotter occasionally may mistake a low-hanging cloud for a tornado and give a bad report, but callers in Arkansas three weeks ago and in South Carolina three days later intentionally provided false information about storms during severe weather alerts.

Someone claiming to see the storm in Bella Vista, near the Arkansas-Missouri state line, e-mailed a photograph of what he said he saw to a Missouri television station. The image was actually an Associated Press photo from a March 2007 tornado in eastern Oklahoma.

In Charleston, S.C., a caller on a telephone line reserved for National Weather Service storm spotters reported damage in Liberty County, Ga. Radar readings already had caused forecasters to issue a tornado warning, which the reports from the ground gave more urgency.

“We didn’t have any reason to dispute the accuracy” of the reports, said Michael Emlaw, who runs the Charleston office. His office sent storm reports to the media.

Easy access to near real-time weather information can aid people as severe weather approaches, letting them gauge whether they truly are in a storm’s path. The same technology can let hoaxers create a credible report – and that makes forecasters waste resources looking for a storm that isn’t there and worries people in the path of the nonexistent storm.

A spokesman for the National Weather Service headquarters outside Washington said he could find no record of a hoaxer being prosecuted.

Debbie Groom, the interim federal prosecutor for western Arkansas, said pursuing fines or jail time would depend on whether the government can prove someone deliberately tried to mislead forecasters. “Something like that wouldn’t apply for an innocent mistake,” she said.

Forecaster John Robinson of the National Weather Service office at North Little Rock believes the recent incidents are worthy of prosecution.

“They even sent a picture and talked about wiping out a McDonald’s. That is not a case where somebody was just mistaken,” said Robinson, the office’s severe weather coordinator.

“At lunchtime, there’s going to be many people inside and a sheriff or a cop will hear that report and turn on his lights and speed over there,” he said. “If he gets into a wreck and is killed, there will be very serious charges” against the hoaxer.

Since the June 12 hoax in Arkansas, Robinson has told his meteorologists to beware of reports of major damage from storms. “If it’s a single tree down across a road, it’s probably OK,” he said, but if it’s from a hoaxer, “it’s going to be spectacular.”

Brandon Beck, a television forecaster at KYTV in Springfield, Mo., went on the air with the first hoax report of the Bella Vista tornado. He also relayed word to the Tulsa weather service office, which already had turned its attention to other storms. Within minutes, an Arkansas TV station reported on the fake twister.

“Cars blown off road on Highway 79,” came one report from the hoaxer, followed 10 minutes later by: “I am watching this move right now! I have 2 people in my Ford and it is moving very slow … 2 minutes away from Pea Ridge National Park … it just took out a McDonald’s.”

When McDonald’s employees told TV reporters that the restaurant was untouched, it was clear what had happened. Forecasters then filed a complaint with federal investigators.

According to Chris Vaccaro, a weather service spokesman in Silver Spring, Md., weather-reporting hoaxes are uncommon, with maybe one in an average year. Two in less than a week is surprising.

“In the unusual case when false weather information is intentionally sent by an individual, either directly or indirectly, to the NWS, it is treated with the utmost seriousness,” Vaccaro said. “Appropriate law enforcement authorities are contacted and NWS employees are instructed to fully cooperate with investigations conducted by such authorities.”