Hurricane 'Cone of Uncertainty' shrinking this year
Thursday, April 19, 2018, 12:46 - The National Hurricane Center has made some annual changes and improvements to the forecasting tools they use to predict devastating storms. One of the biggest being the 'Cone of Uncertainty' shrinking for the upcoming 2018 hurricane season. The forecast cone has been instrumental in hurricane forecasting and the NHC plans to shrink that cone as their forecast continues to get better.
Last year was a year that broke a 12 year major hurricane landfall drought in the U.S. and the outlook for 2018 could be just as destructive.
After damaging and deadly storms like Maria, Harvey and Irma, we question if these upcoming changes could have made a difference if implemented last season. In an interview with Daniel Brown, Senior Hurricane Specialist and Warning Coordination Meteorologist with the National Hurricane Center, he explains how every year is just as vital in improving public messaging and preparations.
"It's important to remember that no matter what those forecasts suggest, it only takes one storm," warns Brown. "It's about impact, not the number of storms." More on his interview below.
FOUR MAJOR CHANGES
1. The Cone Of Uncertainty will get smaller. The size of the tropical cyclone track forecast error cone for the Atlantic basin will be smaller this year, but a little larger at the longer forecast times in the East Pacific. The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of imaginary circles placed along the forecast track (at 12, 24, 36 hours, etc.)
2. The NHC Public Advisory will now discuss forecast information beyond 48 hours. The NHC Public Advisory is a text product that contains a list of all current coastal watches and warnings and gives pertinent storm information, including general forecast and hazard (storm surge, wind, rainfall, tornadoes, surf) information. The forecast information contained within the advisory will now include information beyond 48 hours. Previously, these advisories were limited to a discussion of a tropical cyclone’s track and intensity forecast through 48 hours. This change will allow public advisories to discuss the track and intensity forecast routinely through 72 hours, and allow the flexibility to discuss the forecast through 5 days when conditions warrant.
3. NHC will begin issuing 48-hour hurricane-force (64-kt) wind radii forecasts. NHC will begin issuing hurricane-force (64-knot) wind radii forecasts at the 48-hour forecast time. These wind radii will be provided in the Tropical Cyclone Forecast/Advisory Message (TCM). Previously, the NHC provided hurricane-force wind radii forecasts out to 36 hours. The NHC Forecast/Advisory will now include a forecast of tropical-storm-force (34-knot) and 58-mph (50-knot) wind radii out to 72 hours and hurricane-force (64-knot) wind radii out to 48 hours.
4. The NHC Key Message Graphic will be available on the NHC website with other tropical cyclone graphical products. This graphic has previously been available in the Top News section of the NHC website and shared via NHC social media accounts (Twitter and/or Facebook). Beginning in 2018, when available, this graphic will be provided with the other graphical products in the active tropical cyclone information section of the NHC website.
INTERVIEW WITH DANIEL BROWN - SENIOR HURRICANE SPECIALIST/WARNING COORDINATION METEOROLOGIST
Q: After a record breaking hurricane season last year, what type of improvements did you look to make first?
A: We really didn't have any one specific item that we wanted to fix first. We are always looking to improve communication and messaging to the public every Hurricane season. We are always (this year included) interested in creating new graphics to help decision makers plan and make the best preparedness decisions when it comes to potential impact.
Q: Could any of these improvements changed outcome with Harvey, Maria, and Irma last season?
A: These improvements help with any storm we face moving forward. Some lessons learned from the last years season it to make sure we do our best with "consistent" messaging from the WPC and the local NWS offices too. In a flooding case like Hurricane Harvey, utilizing our call to action plans for the public. Telling people to not venture out into flood waters, to stay where you are until it's safe. It's about Public safety and public awareness in a disaster like Harvey.
Q: What was he biggest challenge when it comes to refining the Cone of Uncertainty?
A: The cone continues to improve with record low errors last season, this we are proud of. The thing to remember is the size of storms are not going to change any time soon.
Q: Early outlook on the 2018 Hurricane Season? Could we see a repeat?
A: Last year we had a very impactful year with 4 major landfalls on U.S. soil. This is a reminder to us here at the NHC why we need plan early for the season so people are as prepared as they can be. As seasonal forecasts become available (we have not issued the official NHC Hurricane forecast yet) we will all have an idea of what we may be in for. It's important to remember that no matter what those forecasts suggest, it only takes one storm. It's about impact, not the number of storms.
Q: Are there tools that were tested last season that will be implemented this season?
A: Yes, last year we were running an experimental Tropical Storm Force winds graphic. This would show reasonable and earliest likely time of impact. This year this product (based on great reviews) will be fully operational. Last we started issuing Storm Surge watches and Warnings and will continue to do this again this season.
THE DIFFERENCE BETWEEN A STORM SURGE WATCH/WARNING
Storm Surge Watch: The possibility of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 48 hours, in association with an ongoing or potential tropical cyclone, a subtropical cyclone, or a posttropical cyclone. The watch may be issued earlier when other conditions, such as the onset of tropical storm-force winds, are expected to limit the time available to take protective actions for surge (e.g., evacuations). The watch may also be issued for locations not expected to receive life-threatening inundation, but which could potentially be isolated by inundation in adjacent areas.
Storm Surge Warning: The danger of life-threatening inundation from rising water moving inland from the shoreline somewhere within the specified area, generally within 36 hours, in association with an ongoing or potential tropical cyclone, a subtropical cyclone, or a posttropical cyclone. The warning may be issued earlier when other conditions, such as the onset of tropical storm- force winds, are expected to limit the time available to take protective actions for surge (e.g., evacuations). The warning may also be issued for locations not expected to receive life- threatening inundation, but which could potentially be isolated by inundation in adjacent areas.