A radar glitch at the Medford airport has grounded the facility's cloud-seeding balloon, which combined with heavy fog this week to delay or cancel numerous flights, airport officials said.
The radar issue does not affect airplane flight safety, as planes can land and take off once the fog clears on its own, Rogue Valley International Medford Airport Manager Bern Case said.
It would most likely be safe to fly the unmanned CASPER balloon with the current radar, but Case said the airport has emphasized extreme caution. The balloon is used to release dry ice pellets for cloud seeding, to create openings in the fog that would allow landings or take-offs.
"The tower has had a challenge with the radar and we just can't seed without the balloon," Case said. "It's been a long couple of days."
The fog caused between five and seven flight delays on Thursday. Several people were stranded for hours on flights heading in all directions, Case said.
Among those stranded far from home was Jacksonville resident Dana Winkler.
Winkler earlier this week flew to Los Angeles for a work meeting. She quickly found that the Rogue Valley had become an impregnable fortress when fog socked in the area, stranding her in Portland.
"I didn't expect to be gone long, so I didn't pack a lot of essential items," she said.
Airline officials told her she would have to plan on spending a long day at Portland, not leaving until a late flight on Friday.
Frustrated, Winkler booked at rent-a-car at a steep rate for the drive back to Jackson County.
"You can't be gone for too many days because you start missing work," Winkler said. "I'm just glad to be back home."
Additional flights from Portland and San Francisco were delayed Friday.
Case said the airport has scrambled to squeeze as many people as possible onto flights in the past 24 hours to clear up the backlog of passengers.
"It has set us back, but we are trying to get people where they need to go," Case said.
In the meantime, CASPER will remain in the hangar, unable to do what it does best.
The Cable Attached System Providing Effective Release, known by the catchier acronym CASPER, is an 18-foot helium-filled balloon that hoists a cylinder of dry ice pellets.
After being sent aloft, the balloon is pulled along by a truck to seed the clouds above the runway area. The pellets freeze the fog, creating snow, which drifts to the ground and clears the air.
It cuts a wide swath in the fog that enables planes to come and go.
"When we can't get the balloon in the air, Mother Nature wins," Case said.
The airport hopes to have the balloon available this weekend.
It likely will be needed, as the stagnant air and freezing fog is expected to stick around the valley until the middle of next week, according to National Weather Service Meteorologist Mike Petrucelli.
An air stagnation advisory originally set to expire Sunday has been extended until 10 a.m. Tuesday, the National Weather Service reported Friday.
Because of limited air movement, a high pressure system will remain in the area, trapping pollutants and resulting in thick, freezing fog in the Rogue Valley.
The area needs a storm system to move in to blow the stagnant air away and clear the skies, Petrucelli said.
"This is going to hang around for the next few days," he said. "The pattern does not look like it's going to change."
Reach reporter Chris Conrad at 541-776-4471 or email email@example.com.