NHC Updates Forecast-Cone Graphics for 2026 Hurricane Season

Yesterday the National Hurricane Center (NHC) published an update for the expected use of their forecast-cone graphics. The NHC has been updating these graphics over the last couple of seasons to visually provide more information. Most of this newly added information was trialed last season as an optional experimental graphic.

The new information includes:

Incorporates all land-based (coastal and inland) tropical storm and hurricane watches and warnings in effect for the continental United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands;

Uses single shading for the entire 5-day outlook cone;

Legend depicts symbols for areas where a hurricane watch and tropical storm warning are both in effect (represented by diagonal pink and blue lines); and

Full and intermediate Tropical Cyclone Advisories are/will be publicly available on hurricanes.gov.

This season’s experimental graphics will change how the NHC determines the dimensions of the cone graphics. On the experimental version instead of using a set of circles set at a 67% experimental error to determine the width of the cone, yesterday’s update notes that:

“Beginning in 2026, the experimental cone will use ellipses anchored at each NHC forecast point, allowing for the experimental cone to capture a range of possibilities for both the speed and direction of the tropical cyclone’s forecast path. NHC will experiment changing two aspects of the cone using ellipses (instead of circles) to account for errors in speed and direction, and the cone will include 90% of forecast track possibilities, instead of the traditional 67% forecast error.”

This should mean that the experimental cones will be larger. The increase in width of the cone will probably be the most noticeable difference, but the overall length of the cone should also increase.