Hurricane forecast cone: what it shows, what it misses, and when to act

Start with the center

The cone shows probable center-track uncertainty—not the edge of danger

NHC forms the cone around forecast positions of a tropical cyclone's center at 12 through 120 hours. The width at each forecast time is based on official track errors from the previous five years. For the 2026 cone, NHC uses the 2021–2025 error sample and sets each circle so that two-thirds of those historical errors fall within it.

• The cone is wider farther into the future because track uncertainty grows with time.
• It does not promise that the center will stay inside; about one-third of historical official forecast errors in the defining sample fell outside the corresponding circles.
• The line and dots are a forecast, not a surveyed path that every part of the storm will follow.
• NHC recalculates cone sizes annually from recent forecast errors, so use the current official graphic and definition.

Look beyond the white area

Wind, surge, rain, and tornado hazards can extend far outside the cone

A tropical cyclone is not a point. NHC warns that its effects can span hundreds of miles. The center can remain inside the cone while dangerous weather reaches communities well outside it—or passes one side of the forecast line instead of directly over it.

The orange and red wind shading on an NHC cone graphic shows the maximum possible extent of current tropical-storm-force and hurricane-force winds in each quadrant. It does not mean every point in a shaded area is experiencing that wind speed.

Use the exact product

An outlook, forecast, watch, and warning answer different questions

These products form a sequence of increasing local detail, but they are not interchangeable. Read the title, issue time, valid period, affected area, hazards, and official instructions in the newest product for your location.

7-Day Tropical Weather Outlook

Shows where disturbances may form into tropical cyclones and gives development probabilities. It is not a track cone, a local impact forecast, a watch, or a warning.

NHC track forecast and cone

Shows the predicted center positions and the historical track uncertainty around them after NHC is issuing advisories. It does not define the full hazard area.

Local forecast

Describes expected wind, rain, timing, and other conditions for a place. Your local NWS office also explains the most important potential impacts in its Hurricane Local Statement.

Hurricane Watch

Hurricane conditions are possible in the specified area. NHC generally issues the watch 48 hours before the anticipated start of tropical-storm-force winds, when preparation may become difficult or unsafe.

Hurricane Warning

Hurricane conditions are expected somewhere in the specified area. NHC generally issues the warning 36 hours before the anticipated start of tropical-storm-force winds. Preparations should be complete; evacuate if local officials order it.

Tropical Storm and Storm Surge Watches and Warnings cover their own hazards and areas. A place can need action even when it is outside the cone, and being inside the cone does not automatically mean a place is under every type of warning.

Read the dots correctly

A forecast point marks the center and expected category at one time

On the standard NHC graphic, the X marks the current center and black dots mark forecast center positions at labeled times. A letter shows the forecast classification: D for depression, S for tropical storm, H for hurricane, and M for major hurricane.

• A dot labeled H does not mean hurricane-force wind fills the cone.
• A forecast point over land does not mean every nearby community will experience the same conditions.
• A line between points does not show a storm's exact arrival time at every location.
• Category describes maximum sustained wind, not storm surge, rainfall, tornado, or flood severity.
• Compare successive advisories, but make decisions from the newest full set of products—not from one shift in the center line.

Prepare before wind arrives

Use the earliest reasonable arrival time—not only the closest cone point

NHC's primary arrival-time graphic shows when sustained tropical-storm-force winds could begin at a location, accounting for track and storm-size uncertainty. NHC defines the earliest reasonable time as the point before which there is no more than a 10 percent chance those winds will have started. Preparations and evacuations become harder and more dangerous after those winds begin.

1. Know your evacuation zone and more than one route before a storm threatens.
2. Use a watch to finish supplies, charging, shutters, mobility arrangements, and travel decisions.
3. Check the earliest reasonable arrival graphic when deciding when outdoor preparation must stop.
4. Follow local evacuation orders; the forecast cone is not an evacuation map.
5. Keep checking official updates because track, size, intensity, and hazards can change.

A three-question check

Make the decision from hazards, location, and timing together

If official local instructions conflict with a simplified social post, old screenshot, or general guide, follow the current NHC, NWS, and local public-safety information. Call 911 for an immediate life-threatening emergency.