National Hurricane Center (NHC) to update products in 2024

From the National Hurricane Center on “X” (formerly Twitter); April 11,2024

The National Hurricane Center is updating products and services for the upcoming 2024 hurricane season, including the following:

1) Spanish language advisory text products
NHC will expand its offering of Spanish language text products to include all Public Advisories, the Tropical Cyclone Discussion, the Tropical Cyclone Update, and Key Messages in the Atlantic basin, and the Public Advisory, the Tropical Cyclone Discussion, the Tropical Cyclone Update, Key Messages, and the Tropical Weather Outlook in the eastern Pacific basin. These products will be issued experimentally in 2024 and will use AI techniques tested in 2023.

2) Issuance of U.S. watches and warnings on Intermediate advisories:
In order to allow for additional flexibilities for the issuance of U.S. tropical storm, hurricane, and storm surge watches and warnings, the NHC/NWS will now have the ability to issue those watches and warnings on Intermediate advisories. Previously, tropical storm, hurricane, and storm surge watches and warnings could only be issued for the United States on full or special advisory packages. Full advisory packages are issued at 5 AM, 11 AM, 5 PM, and 11 PM EDT. Beginning in 2024, NHC will be able to issue U.S. tropical cyclone watches and warnings with regular or intermediate Public advisories.

3) Extension of tropical storm (39 mph, 34 kt) and 58 mph, 50 kt)) wind radii
forecasts to days 4 and 5:

NHC is extending its tropical storm 39 mph (34 kt) and 58 mph (50 kt) wind radii forecasts to days 4 (96 hours) and 5 (120 hours) in the NHC Forecast/Advisory (TCM) in 2024. Previously, NHC has provided these forecasts out to 3 days (72 hours). Hurricane-force (64-kt) wind radii will continue to be provided out to 2 days (48 hours).

4) Weblinks in the Public Advisory:
The Tropical Cyclone Public Advisory (TCP) product will include, as needed, a reference to websites that provide pertinent graphical hazard information beginning with the 2024 hurricane season. The weblinks are intended to help reduce the length of the TCP product and to direct the focus to the most significant and impactful storm surge and rainfall hazards and areas.

5) Change to the time zone reference in the eastern Pacific:
Beginning on or about May 15, 2024, the time zone of reference for most eastern Pacific tropical cyclone forecast products will change. Most of Mexico no longer observes Daylight Saving Time, therefore Central Standard and Mountain Standard time will be used in lieu of Daylight Saving Time within those two time zones. Since Daylight Time is used within portions of Baja California and the southwestern United States, Pacific Daylight Time will continue to be used within that time zone when Daylight Saving Time is observed.

6) Experimental Cone Graphic with a depiction of inland watches and warnings for the United States:
Beginning on or around August 15, 2024, NHC will begin issuing an experimental version of the cone graphic that includes a depiction of inland tropical storm and hurricane watches and warnings in effect for the continental United States. The experimental cone graphic will be available on for both full and intermediate advisories. The current operational cone graphic will continue to be available, and there will be no changes with respect to how watches and warnings are displayed on that graphic (i.e., only coastal watches/warnings will be depicted).

7) Experimental international tropical cyclone rainfall graphics:
The Weather Prediction Center (WPC) in partnership with the NHC will issue an experimental rainfall graphic for the Caribbean and Central America during the 2024 hurricane season. This graphic provides a display of forecast rainfall totals associated with a tropical cyclone or disturbance for a specified time period, based on forecaster discretion. The graphic will allow for enhanced communication of the expected rainfall to external partners, media, and the general public. The product will be publicly available via whenever there is an active tropical cyclone or potential tropical cyclone in the region with a rainfall statement in the Public Advisory.

8) Annual update to the track forecast error cone:
The size of the tropical cyclone track forecast error cone for the Atlantic basin will be about that same through 48 h but slightly larger from 60 h through day 5 as compared to 2023. For the eastern North Pacific basin, it will also be similar in size to the 20232 cone through 60 h, and slightly larger at days 3 through 5.

9) New Marine Forecast Product “Offshore Waters Forecast for the southwestern North Atlantic Ocean”:
The current Offshore Waters Forecast for the Southwest and Tropical North Atlantic and Caribbean Sea issued by the Tropical Analysis and Forecast Branch (TAFB) of the National Hurricane Center will be divided into two new products beginning Tuesday, March 26, 2024 by 1030 AM EDT (1430 UTC). The new Offshore Waters Forecast product will consist of all the Atlantic zones currently north of 19N and be named “Offshore Waters Forecast for SW N Atlantic Ocean” (WMO ID/AWIPS ID FZNT25/MIAOFFNT5). The remaining zones in the Caribbean Sea and Atlantic waters south of 19N will comprise the newly re-configured “Offshore Waters Forecast for the Caribbean Sea and Tropical N Atlantic” (WMO ID/AWIPS ID FZNT23/MIAOFFNT3).

For more information:

NHC_Updates_2024.pdf (