Sunday marks the beginning of the 2014 hurricane season. So far all looks quiet across the Atlantic basin, but experts urge people to prepare for the season while no active storms are of concern and during the state tax holiday, which stretches until June 8.
People should consider how their lives have changed since they last had to consider evacuating or dealing with a storm. Did you get a cat? Have a child? Purchase a home? All these factors change how you treat a potential threatening storm. We're asking everyone this year to know your zone because there have been lots of changes this year. We are no longer asking anyone to evacuate based on wind speed, storm category, or size, but purely on flooding potential with storm surge. So your zone may have changed, please know your zone.
The National Hurricane Center has made several changes for the 2014 hurricane season, below is a press release detailing what we can expect to see this year.
NOAA’s National Hurricane Center (NHC) will implement the following changes to its text and graphical products for the 2014 hurricane season:
Potential storm surge flooding map
Beginning with the 2014 Atlantic hurricane season, NHC will issue the Potential Storm Surge Flooding Map for those areas along the Gulf and Atlantic coasts of the United States at risk of storm surge from a tropical cyclone.
This experimental product provides valuable new information on the storm surge hazard associated with tropical cyclones, by highlighting geographical areas where inundation from storm surge could occur and the height above ground that the water could reach. The map depicts inundation levels that have a 10 percent chance of being exceeded, and can be thought of as representing a reasonable worst-case scenario for any individual location.
The first map will usually be issued at the same time as the initial hurricane watch or, in some cases, with a tropical storm watch. The map is based on the latest forecast track and intensity for the tropical cyclone, and takes into account likely forecast errors. The map is subject to change every six hours in association with each new NHC full advisory package. Due to the processing time required to produce the map, it will not be available until about 45 to 60 minutes following the advisory release.
More information on the Potential Storm Surge Flooding Map can be found at on the National Hurricane Center's website.
Enhancements to Tropical Weather Outlook
During the 2013 hurricane season, NHC extended the time period covered in the Tropical Weather Outlook text product (TWO) to five days on an experimental basis. This year, the experimental 5-day TWO forecasts become operational, and the form of the TWO will change slightly. In addition, NHC will introduce an experimental corresponding five-day Graphical Tropical Weather Outlook (GTWO) to accompany the text product.
The new five-day GTWO, available for both the Atlantic and eastern North Pacific basins beginning July 1, will indicate the formation potential of individual disturbances during the next five days. The current location of existing disturbances will be denoted by an “X”, and shaded areas will represent the potential tropical cyclone formation area for each disturbance during the subsequent five-day period. The areas will be color-coded by development likelihood, with yellow representing a low (<30%) chance, orange denoting a medium (30% to 50%) chance, and red corresponding to a high (>50%) chance of tropical cyclone formation during the next five days. A mouse-over feature will allow users to see the accompanying Outlook text for each disturbance. Clicking on a disturbance will display a graphic showing only that disturbance, which should improve clarity when the forecast genesis areas overlap.
Because the new 5-day GTWO will tend to be busier than the current 48-hr GTWO (which will continue to be produced), the 5-day graphic will not display the locations of existing tropical cyclones. In addition, some aspects of the 48-hr GTWO will change. Previously, the 48-hour graphic denoted disturbances with circles or ovals; beginning in 2014, disturbances will be denoted by Xs, just as they are depicted in the five-day graphic. Active tropical cyclones will continue to be depicted on the 48-hr graphic.
In 2013, TWO formation probabilities were embedded within the paragraph describing each disturbance. In 2014, the formation probabilities will appear in a tabular form beneath each paragraph.
The TWO and GTWO products are issued at 2 a.m., 8 a.m., 2 p.m., and 8 p.m. Eastern Daylight Time. During Eastern Standard Time, the outlooks are issued at 1 a.m., 7 a.m., 1 p.m., and 7 p.m.
Elimination of the Intensity Probability Table
The Wind Speed Probability text product included a table showing the likelihood that a tropical cyclone would be at any of several different intensity categories (e.g., depression, storm, category 1 hurricane, etc.) at fixed points in time (e.g., 12 hours, 24 hours, etc.). This table was originally intended to help users assess the risk of different storm intensities at particular times.
However, NHC has learned that many users consult this table to estimate the chances that a tropical cyclone will make llandfall at one or more of the various intensity categories. Unfortunately, the current methodology provides a highly misleading estimate of landfall intensity. Because of the likelihood of misuse for land-threatening storms, NHC is discontinuing this table until a better procedure to estimate intensity risk can be developed.
To understand the problem, consider a storm that is forecast to be just off the coast at 72 hours. The probability that the cyclone will be at any particular intensity category at 72 hours is estimated by creating a large number of potential track and intensity scenarios, based on the latest official forecast and a climatological error distribution. If the 72-hour forecast is for the storm to be very close to land, a sizable fraction of the potential scenarios will have already encountered land by that time.
For these scenarios, the expected 72-hour intensity will be much lower than what would be expected for a storm that had not yet made landfall. So even though the table accurately assesses what the intensity is likely to be at 72 hours, it grossly underestimates the likely intensity for the moment when the storm comes ashore.
Use of mixed case in NHC Tropical Weather Outlook, Tropical
The National Weather Service began experimenting with the use of mixed-case (upper and lower case) text in some products a few years ago after World Meteorological Organization standards were changed. Beginning in 2014, NHC will issue the Tropical Weather Outlook and the Tropical Cyclone Discussion using mixed case, as well as with the full set of standard punctuation symbols No formatting changes are planned to the other NHC tropical cyclone advisory products at this time.
Tropical Cyclone Forecast cone will be slightly smaller
The size of the tropical cyclone forecast cone will be a bit smaller in 2014. 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.). The size of each circle is set so that two-thirds of historical official forecast errors over the previous five years (2009-2013) fall within the circle.
Other items of interest for 2014
1) Pronunciation guides for storm names including the phonetic pronunciations of all Atlantic and Eastern North Pacific storm names can be found on the NHC website at: Atlantic | Eastern North Pacific
2) The National Hurricane Center has a Facebook page. The NOAA NWS National Hurricane Center page provides updates about the NHC outreach and education campaign and other items that might be of interest to the public throughout the year. During the hurricane season, the site contains a daily tropical weather update for both the Atlantic and eastern North Pacific basins, as well as alerts regarding any tropical cyclone activity as needed. The NHC Facebook page is found at:
3) The National Hurricane Center is on Twitter. NHC has two automated Twitter feeds, one for the Atlantic basin- @NHC_Atlantic (which includes the Gulf of Mexico and Caribbean Sea) and one for the eastern North Pacific basin- @NHC_Pacific
Automated tweets are sent via these accounts whenever NHC issues a public advisory regarding a tropical cyclone (TCP) or a tropical cyclone update (TCU). Each tweet contains a link to access the corresponding product on the NHC website. NHC can also tweet a special message at any time.