What the hurricane cone of uncertainty represents
The cone concerns the future position of the cyclone’s center. NHC constructs it from circles around forecast points, using historical official track errors. The 2026 circles use the 2021–2025 error sample. Their sizes are chosen to contain two-thirds of that sample, rather than to trace the edge of rain, wind or coastal flooding.
Why “cone of probability” needs a careful reading
A historical two-thirds error circle is not a statement that a particular town has a two-thirds chance of a direct hit. The graphic concerns center-track uncertainty, and its outline is not the storm’s size. Some centers have traveled outside earlier cones; hazardous weather also occurs outside the cone even when the center stays inside it.
Forecast points, the cone and coastal warnings
Read each point’s valid time before comparing its position with a coastline. Colored watch or warning segments identify separate coastal messages; they are not interchangeable with the cone’s outline. Read the public advisory’s named warning areas and local agency products. A center track alone cannot determine your address’s warning status.
2026 worked example: Simon’s October 12 bulletin
This is an archived reading example, not a current forecast. Simon Advisory 22 was issued at 21:00 UTC on October 12, 2026 and reported 100 mph maximum sustained winds. Discussion 22 separates the INITIAL analysis from later forecast positions. A later row is a prediction for its stated valid time, not a new observation. Match a cone to the same cyclone identifier, advisory number and issue time before using it with that bulletin.
Read the forecast discussion when the track shifts
In the same October 12 discussion, NHC described increasing model spread and low confidence in the track. That explanation adds context that a single cone image cannot provide. Compare equivalent forecast times and read the forecaster’s reasons; a changed outline alone does not show whether a particular location’s wind or rainfall risk increased.
How to check impacts outside the cone
Use wind probabilities and arrival-time graphics for wind questions, rainfall products for inland flooding, and storm-surge products for coastal water. Then consult the responsible national agency and local instructions. Keep the source and issue time with any image you share, so the next reader can check the latest bulletin.
Frequently asked questions
Does the cone show where winds will reach?
No. It shows uncertainty around the projected center. Wind and rain often extend beyond the cone; check NHC hazard and local warning products.
Is a town outside the cone safe?
No. A town outside the cone may still have dangerous surf, rain, flooding or wind. Local forecasts and evacuation orders should guide decisions.
Is the 2026 experimental cone the official forecast?
NHC publishes an experimental graphic alongside its operational products. Read the label and explanation on the NHC page before comparing them.
Reviewed 2026-10-13. Independent guide; follow NHC and local authorities for safety decisions.