On December 18 , 2010 , the Central Pacific Hurricane Center ( CPHC ) began Process_start monitoring a subtropical cyclone near the International Dateline for possible tropical cyclogenesis .

Shortly before crossing the dateline on December 20 , the CPHC assessed the system to have become a tropical storm .

The storm was assigned Choosing the name Omeka several hours later as it moved into the CPHC 's area of responsibility – which is from 140°W to the International Dateline .