The El Nino forming across the Pacific has been turbocharged by a series of tropical cyclones that helped to shift the direction of trade winds, potentially adding to warming thats evoking parallels with the record 1997-98 event.

The pattern can crimp the hurricane season in the Atlantic, bring more rain across the southern U.S. and warm some northern states.

A Chinese ship hunting for the missing Malaysian jet detected a second, longer unidentified pulse signal as an international fleet races against time to locate the plane before its black-box batteries run out.