The weird cloud pattern that is observed in the sky today from Kathmandu and surrounding area is called Mammatus, aka mammatocumulus.
Mammatus are most often associated with the anvil cloud and also severe thunderstorms.
True to their ominous appearance, mammatus clouds are often signal of a coming storm or other extreme weather system. Typically composed primarily of ice, they can extend for hundreds of miles in each direction and individual formations can remain visibly static for ten to fifteen minutes at a time. While they may appear foreboding they are merely the messengers – appearing around, before or even after severe weather.
For detail: https://en.wikipedia.org/wiki/Mammatus_cloud