This is the first time in my life I saw mammatus clouds in the sky of Kuching!!!!
Mammatus cloud is a special kind of cloud normally appear after heavy storm. Normal clouds like cumulonimbus, stratocumulus, stratonimbus are formed due to convection--- the hot air rises.
However, mammatus cloud is due to the sinking of the air, hence loped-like or sagged.
These photos are taken on my way to Crown Square, Kuching.