· Avalanche
Avalanche is a natural disaster. It begins with the letter a.
A drought is considered a natural disaster. Disease could also be considered a natural disaster.
Kashmir, India earthquake was a natural disaster in 2005. Kohistan, Pakistan avalanche was a natural disaster in 2010.
wildfires
jolt
A Mudslide
not that I know of. sorry. :(
hurricane
No I Don't Think There Is
onamatopeia
twister
Cyclone