A historically intense December coastal storm is blasting the Northeast on Monday after unleashing heavy rainfall, coastal flooding and high winds from Florida to the Mid-Atlantic. More than 700,000 customers had no power midday Monday as gusts surpassed 60 mph in many locations in eastern New England. Boston’s Logan International Airport — where inbound fights were being delayed an average of 2 hours, 14 minutes because of high winds — clocked a gust at 68 mph