Trailspotter
Senior Member.
I've spotted this unusual cloud this morning (August 29, 2015) from the car on the trip to the Norfolk Broads and observed it for about twenty minutes from 11:15 to 11:35 BST (10:15 - 10:35 UTC) until it was obscured by lower clouds. The cloud comprised regularly spaced transverse stripes:
The cloud was oriented along the wind direction (SW), coinciding with a general direction of our road (A11) and was moving northeast a bit faster than the car.
Interestingly, the cloud appears on the Terra satellite image taken at about 10:38 UTC, just a few minutes after my last photo:
From this image, the cloud's length was about 20 miles. Also, by the time, its distal end was already over the North Sea, some 35 miles away from our location at the time of the last photo. Using Google Earth, I've estimated the cloud's altitude being about 30,000 ft (9 km).
The cloud's wavy appearance suggests it may have resulted from the Kelvin-Helmholtz instability.
The cloud was oriented along the wind direction (SW), coinciding with a general direction of our road (A11) and was moving northeast a bit faster than the car.
Interestingly, the cloud appears on the Terra satellite image taken at about 10:38 UTC, just a few minutes after my last photo:
From this image, the cloud's length was about 20 miles. Also, by the time, its distal end was already over the North Sea, some 35 miles away from our location at the time of the last photo. Using Google Earth, I've estimated the cloud's altitude being about 30,000 ft (9 km).
The cloud's wavy appearance suggests it may have resulted from the Kelvin-Helmholtz instability.