The scale of fighting was enormous : by 1970 the ARVN was the world 's fourth largest army , with the PAVN being similar in size at around a million regular soldiers .

Continued strengthening Cause_change_of_strength ensued Coming_to_be as Calvin curved Motion_directional from its initial westward track northward , and was upgraded Cause_to_make_progress to a hurricane Catastrophe on July 6 Calvin eventually turned Becoming northwest , and became Becoming a Category 2 hurricane Catastrophe on the Saffir–Simpson hurricane wind scale ( SSHWS ) .

By October 20 , Michael peaked Cause_change_of_position_on_a_scale as a Category 2 hurricane Catastrophe on the Saffir-Simpson hurricane wind scale at a relatively high latitude of 44°N .

On October 23 , Olivia attained hurricane status , and the next day reached Arriving Category 3 intensity on the Saffir-Simpson scale just before moving Motion ashore Mazatlán in northwest Mexico .

The storm Catastrophe soon moved Motion out to sea as a Category 2-equivalent hurricane on the Saffir–Simpson hurricane wind scale , persisting Presence off of New England before dissipating Departing south of Nova Scotia on 25 August as a markedly weaker storm .