megastorm

• mega-storm

From mega- +‎ storm.

megastorm (plural megastorms)

1. A major storm (weather phenomenon) capable of causing catastrophic damage.
   • 2012 October 30, Associated Press, “NYPD Making Its Presence Known; Mayor Calls Sandy 'Storm Of Historic Intensity'”, in CBS‎^[1]:

     The megastorm Sandy caused 13-foot storm surges in the city.

• superstorm