Part 3: A communication nightmare
On October 23, 2012, the European Center for Medium-range Weather Forecasts (ECMWF) computerized weather forecast model was suggesting the metamorphosis of a Hurricane by the name of Sandy into a monstrous extra-tropical cyclone. This is not uncommon for late season tropical cyclones racing into the North Atlantic.
What was disturbing-the ECMWF also indicated an unprecedented northwestward curve by the storm into the Northeastern United States-an area often spared from tropical trouble. Yet, even as late as October 25, the American Global Forecast System (GFS), was still struggling to display the northwestern curve inland being shown by ECMWF solutions.
Regardless of the serious forecast challenges, experts at the National Hurricane Center (NHC) interpreted the available data well. Storm track, wind and surge forecasts all exceeded the average skill of typical tropical cyclone forecasts.
So if the forecast was good, how then has the communication of this event information become infamously poor?
Meteorologically speaking, Hurricane Sandy presented unprecedented challenges to the weather enterprise. First, the storm was massive and pegged to affect a large number of states with a variety of hazards that are not typical of a tropical system. Second, there were a number of factors made this storm an ambiguous one to categorize. This dissention between forecasters and weather textbooks contributed to serious troubles in communicating potential impacts.
The National Weather Service (NWS) and Emergency Managers began discussing options for communicating the potential hazards more than five days in advance of the storm coming ashore. The consensus decision three days before landfall was to have NHC bulletins in the landfall areas in addition to local National Weather Service office bulletins highlighting specific threats. High wind watches were issued more than 60 hours prior to landfall.
This was done due to Emergency Managers having an adamant preference that warning type NOT be changed once issued. Doing so would cause an added level of confusion, compromising preparation and evacuation efforts.
It was during that time frame when hurricane watches WOULD have been issued, yet Sandy's offshore transition to a post-tropical cyclone was still uncertain.
At this time, the prototypical government red tape caused chaos.
Based on NWS policy, had hurricane bulletins been issued and Sandy had become post-tropical while offshore, there would have been three options.
1. Following existing protocol, NHC would cancel tropical bulletins and transfer forecast responsibility to local offices. This was exactly what emergency managers requested not to happen.
2. Despite a post-tropical transition, continue to call Sandy a hurricane in order to maintain NHC advisories. The NHC and NWS viewed an intentional misrepresentation of the storm as a potentially critical blow to the organizations' credibility.
3. Properly call Sandy post-tropical but continue to issue NHC advisories. The NWS had not developed a procedure for releasing post-tropical forecasts with tropical bulletins and did not want to risk implementing untested procedures at a critical moment.
Thus, with seemingly no guaranteed option, the NWS proceeded with the issuance of ‘high wind' and ‘flood' watches, communicating this warning strategy with emergency and media partners.
Public interpretation of the warnings issued and other recent events led to the perception that Sandy was under-warned.
First, for most, a hurricane warning simply conveys more seriousness than a ‘high wind' and/or ‘flood' warning. Second, the region had been under a hurricane warning just one year earlier for Irene. The area spent the duration of Irene on its weaker western side with the height of the storm occurring during low tide. Sandy on the other hand was much bigger, hooked inland bringing the strongest conditions ashore during a high tide.
A full assessment of the risk perceptions and preparedness actions of Mid-Atlantic residents for Hurricane Sandy can be found in the Wharton Report.
While this dilemma served as a reminder to the public to take all watches and warnings seriously, the National Weather Service was able to reach some goals and find solutions to prevent similar confusion in the future. The NWS has now adopted a policy that allows the National Hurricane Center to continue advising on systems of tropical origin as long as they do pose a significant threat to life and property-meaning tropical or hurricane warnings may be maintained if such conditions are expected. In addition, Sandy further emphasized the need for the storm surge specific forecast products which were accelerated and just rolled out for the beginning of the 2014 hurricane season.
You can get forecasts from Meteorologist Josh Eachus weekdays on 2une-In from 5-7am and News 2 at Noon from 12-1pm. Additionally, you can get the fastest and latest forecasts and weather news by checking in with wbrz.com/weather, connecting with Josh on Google+ and following him on Twitter.