GREEN BAY, Wis. (WFRV) – Green Bay and the Fox Valley experienced another round of dense fog this weekend and early this week, reducing visibility to 1,500 feet in some locations.
A freezing fog advisory has been issued for the region for the first time since 2016 as temperatures dip below freezing.
Dense fog may slow travel to work or school, while it may also cause delays to local airport operations. As pilots descend from their cruising altitude to their assigned runway, they look for signs that an airfield is ahead, such as runway lights or notable objects near the airport.
When fog becomes trapped in the lower atmosphere, pilots rely on computers in modern aircraft to guide them to the runway, which may not be able to see the ground until several hundred feet above the ground.
Green Bay Austin Straubel International Airport Director Marty Piette said newer planes can fly in these conditions, but dense fog can still cause delays on the ground.
“All commercial airlines are equipped to fly in any weather conditions, but again, airlines will not allow their aircraft to operate when visibility reaches 400 meters. General Aviation Transportation, small privately owned aircraft, and small single-engine aircraft cannot operate in this type of weather,” Piette said.
Pilots follow a set of rules set by the U.S. Federal Aviation Administration (FAA) for flying aircraft under specific weather conditions. Weather conditions are determined by the airport's horizontal visibility and cloud height as reported by weather stations.
When clouds are below 1000 feet and visibility is less than 3 miles, only pilots licensed to fly the airplane with the assistance of onboard navigation aids may fly. Small aircraft with pilots who are only authorized to operate using visual terrain will be grounded until weather conditions improve.
Many morning connecting flights out of Green Bay were canceled or delayed Sunday and Monday morning, according to the app FlightRadar24. Piet said several factors may have contributed to the slowdown in air travel that morning.
“So you also need to check the weather at your destination airport. That's why all of our flights connect through Detroit, Minneapolis, Chicago, or Atlanta. If those airports experience bad weather, There could be an impact here as well. But I think some of the cancellations and delays that we saw yesterday were probably affected by the fog here as well.”
Piette suggests downloading airline apps to get up-to-date information on delays and gate changes, so there's no need to rush to arrive if you run into delays before you leave home.
