Can a high pressure system prevent a hurricane from coming ashore?

Answer 1

It can if it is in the right place. The path that a hurricane takes is strongly influenced by high and low pressure systems in the vicinity. If a hurricane is approaching land where there is a high pressure system, then the hurricane will likely change course, tending to follow a clockwise path around the high. That said, if a high pressure system is in another location, it may steer the hurricane toward land. Such a case happened in 2012 when a high pressure system over Greenland caused Hurricane Sandy to make an unusual westward turn and make landfall in the U.S. The paths of many Atlantic hurricanes are influenced by the Bermuda High, a semi-permanent high pressure system over the north-central Atlantic. It causes the common trend of hurricanes to start out moving west and gradually turn north. If the high is centered father east, hurricanes will tend to make that northward turn far to the east, causing them to stay at sea. If the high drifts westward storms may make the turn later and end up either hitting the U.S. East Coast, the Caribbean Islands, or enter the Gulf of Mexico.