Lift is caused by a pressure difference across the wings.
The cloud that forms over the wing is to do with the drop in pressure on top of each wing.
Normal clouds form when there is too much water vapour for the air to hold.
Basically, when the atmosphere is unable to hold the water vapour at a certain temperature and pressure, it saturates and we see cloud.
Condensation point depends heavily on temperature, pressure and how much water vapour is in the atmosphere.
If you drop the pressure (like above the wing of a plane on landing), the air can no longer hold the water vapour in gaseous form and the air saturates (condensation).
Similar results can be achieved if we think of this in terms of temperature.
If the air is rich in water vapour, dropping the temperature adequately would result in the air having to saturate (condensation and cloud formation).
Just noticing the trailing lines are not actually form the wingtips themselves but the principle is the same.
Wingtip (or wake) vortices are circular patterns of rotating air left behind a wing.
If you have made it this far, this is really worth a watch...
Stunning example of wing condensation and wake vortices. Notice the weather conditions... humid.
The changes in pressure on the wing and within the wake vortices allows the air to saturate.
Basically, in certain weather conditions, we are able to see the impact of changes in pressure as the plane distorts the atmosphere around it.
So cool.
Worth noting that this is not the same as a contrail.
Contrail is short for condensation trail but forms when water vapour (produced by the combustion of fuel in airplane engines) condenses upon soot particles or sulphur aerosols in the plane's exhaust.
Incessant heavy rain will pile into the Pacific Northwest, USA 🇺🇸 & British Columbia, Canada 🇨🇦 in the next 72 hours due to a significant atmospheric river event.
Flooding & landslides are highly likely. The atmospheric warmth & moisture can be traced all the way to the tropics.
A strong meander in the jet stream allows Alaska to cool under Arctic air but also helps lift Tropical warmth & moisture into British Columbia & the Pacific Northwest.
Notice how the atmospheric moisture aligns and focuses on the same area. This is like nature's firehose. Extreme rain and locally very high freezing levels expected. Meteorologists call this an atmospheric river.
Some refer to this atmospheric river as 'the Pineapple Express'.
You can see the thunderstorms piling into the east coast of Sicily all day, wrapped around a broader circulation from a developing cyclone to the south.
Catania (home to over 500,000 people) was in the bullseye for near constant thunderstorms today.
Explosive cyclogenesis under a rip-roaring jet stream in the Pacific is about to bring extreme weather down the west coast of North America.
Nerd bit: I have contoured mean sea level pressure under the jet to show the text book interactions of the left-exit. Poetry in motion.
This is how the wind gusts look as the low pressure rapidly develops. The storm is likely to reach hurricane force out at sea with waves of 30-50 feet.
Nasty.
Large rainfall totals incoming as tropical moisture blasts along atmospheric river like a firehose.
Some relief for the extreme drought covering much of western USA.