NOAA's National Weather Service announced today that, starting June 1, the definitions of hurricane and tropical storm watches and warnings will be broadened to allow these watches and warnings to be issued or remain in effect after a tropical cyclone becomes post-tropical, when such a storm poses a significant threat to life and property.
In addition, the NWS would ensure a continuity of service by allowing the National Hurricane Center to issue advisories during the post-tropical stage. These changes were motivated by the special challenges posed by Hurricane Sandy, which was forecast to evolve from a hurricane to a post-tropical cyclone prior to reaching the coast.
"Our forecasters now have more flexibility to effectively communicate the threat posed by transitioning tropical systems," said Louis W. Uccellini, Ph.D., director of NOAA's National Weather Service.
"Sandy's forecast was remarkably accurate and under a similar situation in the future, forecasters will be able to choose the best option to underscore the urgency involved".
This policy change was first proposed during the NOAA Hurricane Meeting this past November and has since been the focus of much discussion in the meteorological and emergency management communities, in forums such as the American Meteorological Society Annual Meeting in January and the National Hurricane Conference in March.
This change is also supported by preliminary findings from NOAA's service assessment on Sandy, which will be released in May.
"I would like to thank everyone for their open and candid feedback on this proposal," said Rick Knabb, Ph.D., director of NOAA's National Hurricane Center. "Keeping communities safe when a storm threatens is truly a team effort and this change reflects that collaboration".