GREEN BAY, Wis. (WFRV) – Green Bay and the Fox Valley saw dense fog roll in once again this weekend and early this week that dropped visibilities to a quarter mile in some spots.
With temperatures below the freezing mark, the area saw its first Freezing Fog Advisory since 2016.
While it can slow down travel to work or school, dense fog can also delay operations at local airports. When pilots descend from cruising altitude to the assigned runway, they look for signs that the airfield is ahead, which can include runway lights or notable objects near the airport.
When fog is locked in at the lower levels of the atmosphere, this causes pilots to rely on the computers equipped on modern aircraft to guide them to the runway and may not spot the ground until a few hundred feet above.
Green Bay Austin Straubel International Airport Director Marty Piette says that while newer planes can fly in those conditions, dense fog can still cause delays on the ground:
“All the commercial airline carriers, all of them are equipped to fly in any type of weather conditions, but again, once we get down to that quarter-mile visibility, the airline does not allow the aircraft to operate. General aviation traffic, the smaller, privately owned aircraft, small single engine aircraft, they won’t operate in weather like this.”, says Piette.
Pilots follow a set of rules on which aircraft can fly in certain weather conditions put out by the U.S. Federal Aviation Administration (FAA). The weather conditions are determined by the horizontal visibility at the airport as well as the height of the clouds reported by the weather stations.
If the clouds are below 1000ft and the visibility is less then three miles, only pilots with licenses to operate the plane with the assistance of navigational aids on board can fly. Smaller aircraft with pilots only licensed to operate through the use of visual terrain are grounded until weather conditions improve.
According to the application FlightRadar24, many of the morning connection flights out of Green Bay were either canceled or delayed on Sunday and Monday morning. Piette says a few factors may have been involved in slowing down air travel those mornings:
“So you have to look at the weather at the destination airport as well. so all of our flights connect through Detroit, Minneapolis, Chicago, or Atlanta. If there’s bad weather at those airports, that can also have an impact here. but I think yesterday some of the cancellations or delays that we saw were probably impacted by fog here as well.”
Piette suggests downloading your airline’s app to keep up to date on delays and gate changes, and if you have a delay before you leave the house, there is no rush to get there.