This is amazing!

Humid atmosphere conditions allow us to see how air passes over an aircraft. The trailing lines are known as wingtip vortices.

🎥 Via @controladores

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.

This example makes it clearer. Source: phys.org/news/2018-05-w…
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.

en.wikipedia.org/wiki/Contrail
The vortices produced by the turbulent wake of the plane can be a hazard for the next plane coming in to land

The turbulent wake can cause loss of lift and stability to the aircraft behind and must be accounted for in spacing of landings.

More here: skybrary.aero/articles/wake-…

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More from @ScottDuncanWX

13 Nov
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.
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Some refer to this atmospheric river as 'the Pineapple Express'.
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Alaska shivering with brutal early winter cold Meanwhile California sets daily heat records.
We often see extreme anomalies at this time of year...

The long nights in the Arctic are starting to build the cold while summer heat lingers in the south.

However, this is exceptional.

🔵= colder than average for time of year
🔴 = warmer than average for time of year
Some more info on the daily heat records in California

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Enormous rainfall totals have fallen under slow moving thunderstorms.

🎥 via @3BMeteo

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.

Sat via @metdesk/@eumetsat
Truly horrific scenes emerging from Catania, Sicily 🇮🇹

Continuous thunderstorms today have turned the streets into raging rivers.

Via 🎥 @myrtamerlino

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Record-breaking low pressure off the coast of the Pacific Northwest.

The storm also delivered record-breaking rainfall to parts of California after record-breaking dry streak.

Record-breaking number of times I have written record-breaking in a tweet.
More on the rainfall/lack of rainfall records

The storm was well forecast.

This thread summarised some of the big-picture in the lead up to the storm

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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.
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Nasty.
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Some relief for the extreme drought covering much of western USA.
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