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 head or tail 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 sudden strong wind hits the aircraft from behind, it can slow the effective airspeed of plane down considerably," Sosnowski said. The change in airspeed could cause the plane to stall.
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.
A plane pulls into the gate at JFK International Airport. (AP Photo/Mary Altaffer)
"Any airport can have wind issues but areas right along the coast at mid-latitudes can be windy more often," 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.
"Airports at mid-latitude locations, where large-scale 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 due to the interaction of lake and sea breezes."
Doppler radar has helped increase the safety for airports in terms of wind monitoring.
"It has made landing and takeoffs much more safe," Sosnowski 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."
Due to a cable line issue, the National Oceanic and Atmospheric Administration's weather radios are currently out of service throughout Oklahoma.
Lifeguards along the East and Gulf coasts are preparing to deal with one of the greatest beach dangers: rip currents.
A dangerous and life-threatening flooding situation will continue into Memorial Day, across portions of Texas, Oklahoma, Kansas, Arkansas and Missouri.
Showers and thunderstorms threaten to interfere with Memorial Day festivities across more than half of the United States.
Many areas in the Eastern states will have consistent summerlike heat and a buildup of humidity for the last week of May.
People heading to the Southeast coast for a a dip in the Atlantic Ocean this Memorial Day holiday weekend are being put on alert for dangerous rip currents.
New York City (1861)
Snow was reported.
Tornado swarm in Iowa, Illinois and Michigan; 74 killed.
Morden, Manitoba (1933)
Flash flood washes away bridges, ruined crops, and killed livestock.