How to predict when contrails are likely to form over a specific location using public data?

Asked by: Sheryl Siebert

How well can Persistent contrails be predicted?

Contrails are persistent when R H i ≥ 1 . Thus, the summary of this analysis is that while contrail formation can be forecasted quite reliably, their much more important property of persistence cannot currently be predicted reliably.

Which part of the atmosphere are contrails most likely to appear?

Exhaust contrails usually form at high altitudes; usually above 8,000 m (26,000 ft), where the air temperature is below −36.5 °C (−34 °F). They can also form closer to the ground when the air is cold and moist.

Can contrails predict weather?

Contrail forecasting



Contrails are artificial clouds caused by water vapor from the exhaust of airplanes. Contrails form in the same layer of the atmosphere that cirrus clouds form in. Therefore, the development and behavior of the contrails can give you a clue to future weather just as cirrus clouds do.

What are contrails how do they form?

How do contrails form? immediately behind a jet engine in the expanding engine exhaust plume. A contrail will form if, as exhaust gases cool and mix with surrounding air, the humidity becomes high enough (or, equivalently, the air temperature becomes low enough) for liquid water condensation to occur.

At what height do contrails form?

about 26,000 ft

Contrails are human-induced clouds that only form at very high altitudes (usually above 8 km – about 26,000 ft) where the air is extremely cold (less than -40°C). Because of this contrails form not when an airplane is taking off or landing, but while it is at cruise altitude.

Why do some planes leave contrails and others don t?

Often, aircraft appear to be at the same level with one causing a contrail and the other not. However, the regions of humid air that cause the contrails are known to be wide but shallow. A difference in flight level of 1,000 feet is enough for one aircraft to cause a contrail and the other not.

How high does a plane have to be to have a contrail?

26,000 feet

Contrails form when an airplane is at cruising altitude, which is above 26,000 feet. The air at this altitude is usually around minus-40 degrees Celsius. Contrails form in the same layer of the atmosphere that cirrus clouds form in.

Do contrails predict rain?

The nature and persistence of jet contrails can be used to predict the weather. A thin, short-lived contrail indicates low-humidity air at high altitude, a sign of fair weather, whereas a thick, long-lasting contrail reflects humid air at high altitudes and can be an early indicator of a storm.

What weather is associated with contrails?

In short, contrails are cloud-like streamers frequently observed to form behind aircraft flying in clear, cold, humid air. These condensation trails may form by either of two distinct processes.

Do military jets leave contrails?

The next time you fly in a commercial aircraft through a rain cloud, look for the vapor trails that form over and around the wing. Typical fighter wingtip contrails are shown below. Often, military aircraft can be seen taking off with a black smoke appearing from the engines.

What are the three types of contrails?

There are three types of contrails: short-lived, persistent non-spreading, and persistent spreading.

Do stealth bombers have contrails?

To directly answer your question, stealth aircraft have no special equipment to limit their contrails. The military does though incorporate atmospheric data into their flight planning to minimize the creation of contrails especially during daytime operations.

How long do contrails last?

Satellites have observed clusters of contrails lasting as long as 14 hours, though most remain visible for four to six hours. The long-lived, spreading contrails are of great interest to climate scientists because they reflect sunlight and trap infrared radiation.

Do contrails make clouds?

Planes create their mesmerizing contrails as they soar high in the thin, cold air. Water vapor quickly condenses around soot from the plane’s exhaust and freezes to form cirrus clouds, which can last for minutes or hours.

What type of clouds are contrails?

Contrails are a type of cirrus clouds consisting of predominantly ice particles. A major portion of the water to form these particles comes from the atmosphere itself, and a small portion is from the engine exhaust.

How long do contrails last?

Satellites have observed clusters of contrails lasting as long as 14 hours, though most remain visible for four to six hours. The long-lived, spreading contrails are of great interest to climate scientists because they reflect sunlight and trap infrared radiation.

Why do contrails last longer?

However, atmospheric scientists have explained that some contrails last longer than others because of factors such as the humidity of the air (which can vary quite sharply over short distances) and the temperature of the airplane’s exhaust.

What are the three types of contrails?

There are three types of contrails: short-lived, persistent non-spreading, and persistent spreading.

Do planes dump fuel before landing?

Airplane fuel can be quite heavy, sometimes weighing as much as 6 pounds a gallon. If an airplane holds 5,000 gallons of fuel, that can add up to 30,000 lbs. to the plane’s weight. In fact, lowering its weight is the main reason why airplanes dump fuel right before landing.