Uncooperative weather can be a travel nightmare for airlines and passengers. Snow, rain, fog and wind all have the potential to delay or outright cancel flights. As many saw to start the new year, disruptive snowstorms in the Northeast, which includes some of the world's biggest hubs, took days to get back on track.
Here are some of the most disruptive types of weather for air travelers, with examples of some of the top 20 busiest hubs in the United States where you may encounter these issues.
Trying to fly an airplane in dense fog is difficult because of the reduction to visibility, especially for high-traffic airports such as San Francisco International Airport (SFO).
A plane descends to the San Francisco International Airport amidst fog. (Flickr/angeloangelo)
"In general, the airport is on the Bay and is very conducive to getting marine clouds and fog, with the fog being occasionally dense," said AccuWeather.com Western Weather Expert Ken Clark. "It tends to be one of the foggier airports, especially in the West."
Because of the high volume of traffic that the San Francisco Airport handles, Clark said that they can reduce their runways from two to one, which causes flight delays.
According to research done by Hopper Travel, SFO had less than a 75 percent on-time departure rate for 2011.
Strong winds can be dangerous for planes trying to take off or land. AccuWeather.com Senior Meteorologist Alex Sosnowski said that the biggest problem is strong cross winds that can affect the overall speed of an aircraft at a time when its speed it critical for a safe takeoff or landing.
"If you have a plane landing and coming in at over 100 mph, and a strong wind blows across and hits that tail, it can slow the plane down to 70 mph," Sosnowski said. The change in speed could cause the plane to drop too suddenly.
New York City's John F. Kennedy International Airport's (JFK) location so close to the Atlantic Ocean makes it a location vulnerable to winds.
"Any airport right along the coast at mid-latitudes can be windy," Sosnowski said.
The number of travelers who rely on JFK, however, leads it to have a high number of delays.
A spokesman for the Federal Flight Administration told AccuWeather.com that one-third of air traffic is connected in some way to one of the three major New York City area airports (JFK, LaGuardia and Newark) each day.
"Either as a destination or a connection, there is a such a high volume of traffic that [weather disruptions] can have a large ripple effect," he said.
JFK's average wind speed is 12.2 mph; the highest average wind speed for the lower 48 is 14 mph in Dodge City, Kan.
"Mid-latitudes airports, where storm systems frequently roll through, raise the risk a notch for wind issues," Sosnowski said. "Then, any airport near a large water body raises the risk another notch."
Doppler radar has helped increase the safety for airports in terms of wind monitoring.
"It has made landing and takeoffs much more safe," Sosnowksi said. "This radar can detect variations in the wind, such as those caused by nearby thunderstorms."
The Hopper's research found that JFK averages 43,124 weather-related delays each year, contributing to it's 83-percent on-time rate.
Much like the mid-latitude locations near waters can produce wind problems for aircraft, these characteristics also make these areas vulnerable to snowstorms. Snow and ice will reduce visibility, make runways slippery and can affect the way crucial equipment operates.
Snow flies at Chicago's O'Hare International Airport. (Flickr/Seth Anderson)
With 160,000 weather-related delays each year, Chicago's O'Hare International Airport (ORD) is vulnerable to snow, as well as to winds, rain and other flight-disrupting conditions.
AccuWeather.com Senior Meteorologist Elliot Abrams points out, however, that much of Chicago's snow is not the traditional lake effect, as it is not located on the proper side of Lake Michigan to receive the brunt of its snowfall. Abrams said that the city has received more snow than usual this season, contributing to delays and cancellations out of this major hub.
O'Hare is not the airport with the most weather-related delays, however. That title belongs to the Dallas/Fort Worth International Airport (DFW), which experiences the worst of its weather in the warmer months of the year.
Lightning strikes and the Dallas/Fort Worth International Airport. (Flickr/Caren Mack Photography)
Dan Kottlowski, AccuWeather.com senior meteorologist, said this is attributed to strong daytime heating combining with moisture off the Gulf of Mexico, plus periodic weather fronts and disturbances in the upper atmosphere. These conditions come together to create a good deal of thunderstorms for the area.
Thunderstorms are prone to have strong winds and visibility-reducing rains. The atmosphere around a thunderstorm can add to turbulence in the air, but most planes are equipped for protection against lightning strikes.
DFW is also far enough north to experience cold and freezing delays, which contribute to its 72 percent on-time departure rate.
"They average from one to a half a dozen freezing rain events," Kottlowski said. "Combined with the high volume of traffic they produce, this can throw them off schedule."