Impact of weather on holiday flights

The vacations are in full swing. A sizable number of us pack our suitcases and head out on a plane trip. Few people consider how much the weather over the airport and on the flight path can affect our vacation plans. Rather, we assume that the risk of delaying the launch due to weather conditions is the domain of the winter seasons. Also, few of us, looking up at the sky at the condensation plumes left behind an aircraft, ask ourselves whether they affect weather conditions. It turns out that even in summer, the weather can extend or change our flight, or despite good forecasts, we will encounter cloudy skies in some areas.

The impact of weather on flight

Flight operations in the summer season are generally less affected by weather conditions than in winter. They are not threatened by snowstorms or hours of dense fog that make takeoff and landing difficult. However, despite this, there are times when the impact of the weather is so great that the aircraft cannot take off or, after an unsuccessful landing attempt, has to go into a second circle. Sometimes, too, it turns out that thanks to atmospheric conditions the machine lands earlier than it was scheduled.

Among the summer meteorological threats to aviation, storm activity can certainly be mentioned. It can be a nuisance during takeoff, flight and landing, but can also generate delays even when the aircraft is on the tarmac. A number of dangerous phenomena are associated with the development of storm clouds. These are electrical discharges that can strike the machine on the ground or in flight, damaging its components and necessitating additional maintenance each time.

Thunderstorm clouds are often accompanied by heavy rainfall and hail, strong gusts of ground-level wind or changes in its direction and speed at different heights causing wind uplift. There is also strong turbulence and, due to the significant vertical structure of the clouds, even in summer, icing causing ice to be deposited on the aircraft’s wings and reducing their lifting power.

Hence, pilots are obliged by regulations to avoid storm clouds with a distance of at least 10 km and with an altitude of 1 km above their tops. It is forbidden to fly under the cloud and fly into it (Szewczak, 2014). Aircraft and airports have established so-called minimums for performing flight operations. These are parameters related to, among other things. with the visibility at the airport, the height of cloud cover and the speed and direction of the wind along the runway. If these values are exceeded, takeoff or landing may be halted.

Influence of weather on flight – heavy rainfall

As a result, heavy rainfall accompanying a thunderstorm is particularly dangerous over the airport, as it reduces visibility and water lingering on the runway extends braking distances. In addition, when the storm cloud is accompanied by low-lying stratus clouds, the landing pilot will see the runway too late. At smaller airports, not equipped with advanced ILS systems, this can make landings impossible and result in the need to go around and wait until conditions improve.

Influence of weather on flight – strong and gusty winds

Another threat that storm activity near the airport will carry is strong and gusty winds. Depending on the direction, it affects the length of takeoff or landing. In addition, rapid changes in wind direction and speed over the airport lead to strong turbulence and the phenomenon of wind uplift. This is a situation where there is a significant and sudden change in wind direction or speed at different altitudes. It is particularly dangerous just above the surface when the pilot is performing a takeoff or landing and the aircraft is configured for specific wind conditions. As a result of their change, for example, a sudden increase in headwind speed during landing, the lifting force may increase and the nose of the machine may be lifted, and thus the aircraft will later touch the wheels of the runway and it may not be long enough for safe braking.

Another, much more dangerous case is when there is a reduction in headwind speed or the occurrence of a gust in the tail of the machine during landing. This leads to a reduction in the lifting power of the aircraft and its rapid descent. If the machine is very low or the pilot’s reaction is late, a “hard” landing may occur, in extreme cases before the runway. It may also result in the aircraft having to go into a second circle and attempt to land again. An analogy may be the situation during takeoff. Neither of these cases will be safe and pleasant for passengers.

As you can see, for safety reasons, landing may not be possible until the storm cell has moved away from the airport. The machines will have to wait for favorable weather conditions, circling at a certain point, i.e. staying on the command of traffic control in the hold. Also, planes flying along the route must avoid storm clouds. For single storm cells that are clearly visible to the pilot and weather radar, this should not involve major flight changes and delays. Such storms will also move out of the airport area within minutes, allowing takeoffs and landings.

However, if there are more storm clouds, or if they stack and merge into linear, vertically extended structures of up to 12 kilometers or more, bypassing them and making a safe takeoff or landing may be impossible. There are times when a storm front stretches from north to south across Poland, significantly lengthening the path of a plane flying from western Europe. This may result in the need to land at an alternate airport or even return to the takeoff airport. These are situations in which the decision is made by the pilot, in consultation with traffic control services and the carrier’s authorities.

The impact of weather on airport service work

Also, the work of ground handling during a storm is hampered. Aircraft refueling is prohibited if there is lightning directly over the airport. Heavy rain and wind make it difficult to unload and load luggage. A thunderstorm over the airport may also prevent passengers from getting on and off planes. As you can see, the impact of weather on the work of air service at many levels is significant.

In addition to the dangers of thunderstorm weather, we may also encounter strong and gusty winds during the summer season, which will lead to the occurrence of unpleasant turbulence or result in the wind uplift phenomenon already described. Such situations are more likely to occur at airports located closer to the sea and in mountainous areas with conditions conducive to the formation of mountain waves.

Any of these situations can affect the flight, to extend or have to make up for delays through higher cruising speed, which generates an accumulation of delays and negatively affects the economics of the flight. Despite increasingly accurate forecasts prepared specifically for aviation and the cooperation of synopticians with traffic control and ground handling services, the negative impact of weather on flight operations cannot be fully avoided. However, there are times when we land a few minutes earlier than planned. It can also be noted that scheduled flight times from Poland to western Europe are longer than returns. The differences range from 15 to 20 minutes on flights to London and even more than half an hour when traveling to Portugal or the Canary Islands. This is happening, among other things. due to the weather, which is generally encountered by aircraft on their flight path.

It’s all about the jet stream, which is an intense, narrow and almost horizontal stream carrying huge air masses from west to east. The use of such electricity when traveling east shortens flight times. At the same time, pilots try not to fly into such currents on the way back, so as not to burn more fuel and generate delays. This is made possible by using wind forecasts for high-altitude flights created by international forecasting offices. Also, accurate forecasts of wind direction and speed at congested airports with more than one runway help streamline air traffic and improve flight economics despite unfavorable weather conditions.

Does the flight affect the weather?

We are also experiencing the opposite of the effect of weather on flight. This is due to the formation of condensation trails behind the aircraft and the resulting cirrus feather clouds. These are clearly visible white marks left behind the aircraft. In fact, these are ice clouds formed at an altitude of 8 – 13 km as a result of condensation of water vapor escaping from the engines along with the exhaust gases. From a climate point of view, condensation plumes that last more than 10 minutes(cirrus homogenitus) are important. During the day, they will affect the decrease in air temperature over the area over which they are located, as they are a barrier to long-wave solar radiation. At night, on the other hand, they will act as a quilt, being a barrier to heat escaping from the surface (Kärcher, 2018). This effect is particularly observed within the Channel and Benelux countries.

These are just some of the aspects of weather affecting aviation that can extend or divert holiday travel. It is useful to follow aviation weather forecasts or weather radar images to explore the topic. When a storm front passes through, you can watch for changes in aircraft routes on pages showing air traffic. Sometimes it will just satisfy our curiosity, and at other times it will allow us to prepare for a longer-than-planned trip to our vacation destination.

In the article, I used, among others. From the works:

1. Kärcher B. (2018). Formation and radiative forcing of contrail cirrus, Nature Communications Volume 9
2. Szewczak P. (2014). Meteorology for the airplane pilot, Avia-Test Lech Szutowski
3. https://naukaoklimacie.pl/aktualnosci/wplyw-lotnictwa-na-klimat-smugi-kondensacyjne-i-chmury/ Accessed 24.06.2023
4. https://www.samoloty.pl/artykuly-lotnicze/15037-holding-czyli-procedura-oczekiwania Accessed 24.06.2023
5. https://pl.wikipedia.org/wiki/PrC485d_strumieniowy Accessed 24.06.2023