No matter where an airport is located, severe weather conditions can complicate how decision-makers maintain the safety and efficiency of its logistics and operations. And for many, the colder months bring especially unique challenges having to contend with winter weather, as one blizzard or ice storm can cause a chain reaction wreaking havoc across the globe.
These severe weather events create potentially hazardous conditions that cause cost-prohibitive, inconvenient delays and put lives at risk. According to the Federal Aviation Administration, inclement weather conditions are the most significant cause of flight delays making up nearly 70% of all delays exceeding 15 minutes in an average year. What’s more, is the safety factor. While human error is the most common cause of accidents, the weather is a primary contributing factor in nearly 25% of all aviation accidents.
This is why accurate situational awareness is critical to airports and requires the right tools to effectively assess storms, visibility, wind, precipitation, freezing conditions, runway surfaces and more. When it comes to winter weather, the best aviation weather management systems incorporate a wide range of sensors to produce the most valuable real-time reports and alerts.
Unfortunately, conventional present weather sensors don’t always deliver the necessary information aviation industry decision-makers need to make more accurate weather predictions and reduce costly delays. A significant number of amendments to METAR reports are due to false present weather information. This is typically due to three primary issues:
- Detection: Missed weather events due to insufficient detection sensitivity.
- Identification: Inadequate precipitation identification performance due to a lack of high-quality raw data and unoptimized identification algorithms.
- Field Performance: Increased operational measurement disturbances caused by suboptimal product design and lack of contamination compensation.
Fortunately, by integrating the latest real-time weather and system algorithms with accurate weather observations and reporting, innovative aviation weather management solutions enable comprehensive situational awareness of the weather within and above airport boundaries. Empowered with such solutions, decision-makers can improve the effectiveness and timeliness of weather impact mitigation plans and help pilots avoid or take precautionary measures in inclement conditions. These solutions better maintain safe, efficient operations and minimize downtime when severe weather strikes, most notably with freezing conditions, low visibility and wind.
Staying Ahead of Freezing Conditions
When temperatures plummet, and precipitation falls from the sky, freezing conditions complicate daily operations and require extra time and manpower to ensure safe travel. In addition to causing costly delays and cancellations, extreme cold forces decision-makers to de- and anti-ice aircraft and ameliorate the impact of freezing conditions on runways and taxiways. Unfortunately, the de- and anti-icing processes can have a significant impact on resources. Not only are the fluids used costly, but queuing planes for anti-icing further delays operations.
While Mother Nature cannot be controlled, weather radars can deliver precise meteorological information for a specific area, tracking and nowcasting the location of severe storms. By providing advanced warning of a broad range of approaching weather phenomena, including wind shear, precipitation (type and amount), thunderstorms, microbursts and more, weather radar enables good situational awareness and helps improve safety and airport efficiency since planes can be directed to avoid inclement weather conditions.
In addition, more advanced tools are available to help mitigate the impact of freezing conditions in winter weather, specifically advanced lidar ceilometer technology.
While ceilometers have been an essential part of basic weather instrumentation at airports for many years for the information they provide about cloud height — especially safety-critical, low-altitude clouds — as well as vertical visibility and cloud coverage, new ceilometers on the market go beyond standard cloud height reporting.
Novel lidar ceilometers with depolarization capabilities enable the detection of icing conditions, volcanic ash and sand/dust layers aloft. This provides a much deeper understanding of what is happening in the atmosphere immediately above the airport or in the surrounding area.
Designed for unattended operations, these ceilometers provide cloud height measurements and, thanks to the new depolarization technology. Depolarization can clearly differentiate between solid and liquid particles to help detect essential phenomena that can impact aviation safety and efficiency. With these measurements, decision-makers can notify aircraft how they could be impacted and enable airport operators to take necessary action.
With severe icing conditions serving as a significant weather hazard for aviation, this technology has been beneficial in addressing icing conditions in colder climates. In such environments, icing conditions occur more frequently, and airports must be better prepared. While passenger airplanes can operate in icy conditions, timely awareness is critical for maintaining safe and efficient operations for all types of aircraft.
Taking on Impaired Visibility
Across the globe, low visibility cancels, delays or disrupts flights every day. From rain, fog, snow, sleet and other particulate matter, obscurants can negatively affect visibility, which is especially crucial when the aircraft is maneuvering on or close to the ground.
Good visibility optimizes airport efficiency by maximizing inbound/outbound aircraft capacity, while impaired visibility forces airport operations to slow down to ensure safe departures and arrivals. Most automated weather observing systems struggle to identify these conditions, and human observation is typically necessary to validate the presence of icing. Observers often compile their reports by integrating sensor measurements with visual observation of known landmarks, but human estimation is subjective and prone to error. Without reliable, accurate visibility information, airports cannot operate safely — nor at full capacity.
Categorized airports must have instrumented meteorological optical range (MOR) measurements and a system calculating runway visual range (RVR), the essential factor for enabling air traffic control and pilots to make the correct operational decisions. Visibility, or MOR, can be measured with two approved technologies: transmissometer and forward scatter, with transmissometer technology like Vaisala’s LT31 transmissometer. Forward scatter technology, such as Vaisala’s FD70, is, in addition to the meteorological visibility (MOR), able to measure the drop-size distribution and velocity of falling hydrometeors and offer present weather detection of conditions that were previously hard to identify.
These advances enable automated weather observation platforms to accurately identify real-time conditions in an autonomous operating mode, delivering detailed particle-by-particle analysis that allows for highly reliable frozen-liquid differentiation. The capability to differentiate between frozen and liquid particles and other precipitation identification is essential for visibility and present weather, including RVR.
Wind Shear: Addressing Shifts in Wind Patterns
From wind shear and microbursts to gust fronts and wind shifts, wind remains one of the most dangerous — and difficult to assess — weather hazards. While it may not be the first weather event that comes to mind when addressing winter storms, the sudden change in the direction or velocity of wind, also known as wind shear, is an essential consideration. Most commonly resulting in delays and cancellations, wind shear can also quickly create dangerous situations during takeoff and landing when aircraft might not be able to withstand severe wind-caused disruptions to their flight paths.
While there is no mandate to measure or detect wind shear, failure to do so effectively can put lives at risk and lead to crippling financial damages. Consequently, the impact of wind shear should be accounted for since it occurs at a height and under flying conditions in which aircraft are most vulnerable.
The best aviation weather management systems for wind shear incorporate a combination of up to three measurement technologies: a low-level wind shear alert system (LLWAS), weather radar and scanning wind lidar. LLWAS measures average wind speed and direction using a network of remote ultrasonic sensors fixed around runways and along approach and departure corridors. In addition, weather radar, used during precipitation, can measure the wind field from the entire aerodrome and beyond. Scanning wind lidar, used in clear sky conditions, provides wind shear detection, 3D wind information and wind inversion detection that can measure the entire field, from the runway and its approach and take-off areas.
With real-time detection of wind shear, decision-makers can predict wind changes to prevent accidents and make runway changes to improve airport efficiency.
Embracing Innovation in Aviation
From maintaining scheduled operations to keeping employees and travelers safe, decision-makers with precise and timely weather information can adapt, rapidly react to changing conditions and reduce disruptive delays. Technological advances have opened the door for airport decision-makers to measure and detect severe weather and take the proactive steps necessary to minimize delays and cancellations while keeping operations running as safely and smoothly as possible. With the right aviation weather solutions in place, airports can not only be prepared for winter weather but have the information on hand to address any severe weather event throughout the year.
Kari Luukkonen has a long experience in various roles in Vaisala. Over the last five years, he has been managing Vaisala’s offering for aviation systems and services. His work includes driving the development of the overall weather offering to meet the current and future needs of the aviation market
