NHC Announces Changes to 2025 Hurricane Forecasts
3/12/25 – The National Hurricane Center (NHC) has announced a series of changes to 2025 hurricane forecasts. The changes affect cone graphics, risk maps, prediction periods, forecast uncertainty, and forecast frequency. Let me attempt to summarize and simplify a highly complex announcement.
Experimental Cone Graphic with Depiction of Inland Watches/Warnings
Along with its normal cone graphics, NHC will offer experimental cone graphics that feature inland watches and warnings. The new experimental graphics will now contain diagonal pink and blue lines in areas where hurricane watches and tropical storm warnings are in effect simultaneously.
The current cone graphic that only shows coastal watches and warnings will remain. But research showed that adding inland watches and warnings could help communicate wind risk for those who live away from coasts.
The new, experimental graphics take longer to produce. So, they may appear online up to 30 minutes later than the regular graphics. Here’s an example.
Rip-Current Risk Maps
An increase in fatalities from rip currents during the past decade prompted this innovation. NHC will compile a national rip current risk map from data provided by local National Weather Service offices. It will cover the current day, the next day, and a composite showing the highest risk for both days. However, it will not contain information on surf height.
For more information on NWS surf zone forecasts, rip current risk categories, and rip current safety, visit https://www.weather.gov/safety/ripcurrent-forecasts.
Earlier Warnings for Potential Tropical Cyclones
NHC will now issue potential tropical cyclone advisories up to 72 before the anticipated arrival of a storm. That’s up from 48 hours for watches and 36 hours for warnings. The longer lead times will give people more time to prepare when there is a high risk of significant damage.
Earlier Forecasts for Hurricane Wind Radii Forecasts
Until now, NHC has issued forecasts of storm widths two days in advance. They will now provide those forecasts three days in advance.
Those same forecasts (which also include wave height), will now show the height in meters instead of feet, based on requests from the public.
The forecast wind radii are available in real-time in a geographic information system (GIS) friendly format at the following link: https://www.nhc.noaa.gov/gis/.
Error-Cone Forecasts
As storm forecasting becomes more accurate, error cones are shrinking. This year’s error cones will be 3-5% smaller than last year’s, based on a 36-hour forecast period. 96-hour cones could shrink as much as 9%.
However, this may fool some people who misunderstand what the cones mean. The cone represents the probable track of the center of a storm, not its width.
A storm’s center has an equal chance of tracking along any point within the cone. If people think the cone indicates a storm’s width, they might be lulled into a false sense of security if they are outside a smaller cone.
Frequency of Watch/Warning Updates
NHC will now issue storm watch/warning updates eight times a day instead of four whenever coastal watches or warnings are already in effect. They actually instituted this change last year. So, this is a reminder. You can check for full updates every three hours.
That’s it for the summary of NHC’s changes to 2025 hurricane forecasts. Here also are some helpful links to use throughout the upcoming hurricane season.
Where to Find NHC Information
Live Stream
NHC will livestream forecast updates simultaneously on YouTube and Facebook whenever an area of interest exists that may pose a threat to land. NHC will generally provide these updates around 10:30 AM 4:30 PM CDT.
Outreach
NHC provides outreach and education throughout the year on Facebook at https://www.facebook.com/NWSNHC.
Real-Time Updates on X
For the Atlantic basin (which includes the Gulf and Caribbean), see @NHC_Atlantic.
For storm surge reports, see @NHC_Surge.
Web
National Hurricane Center: www.hurricanes.gov or https://www.nhc.noaa.gov
Explanation of Tropical Weather Outlook Graphics: www.nhc.noaa.gov/aboutnhcgraphics.shtml#GTWO
National Hurricane Preparedness Week: www.hurricanes.gov/prepare.
Hurricane Season Starts June 1
It’s getting to be that time of year again. Early predictions from Colorado State University indicate this should be an average hurricane season based on sea surface temperatures, the El Niño cycle, and accumulated cyclone energy.
But don’t take anything for granted. The I-storm this year will be named Imelda. Remember that one! Names recycle every six years. So prepare for a rerun.
Posted by Bob Rehak on 3/12/25
2752 Days since Hurricane Harvey
