How to Read the Hurricane Cone: What the NHC Forecast Cone Shows
The NHC forecast cone shows the probable track of a tropical cyclone’s center, not the size of the storm or where its impacts will reach. The National Hurricane Center (NHC) builds it from circles sized so that two-thirds of its past official track errors fall inside them. NHC says the entire 5-day path of the center stays within the cone about 60–70% of the time, and that dangerous winds can extend well beyond it.
What does the hurricane cone show?
The cone graphic on hurricanes.gov combines several layers:
- The storm’s current position and its current wind field.
- Black dots for forecast positions of the center out to 5 days, each with a letter for forecast strength: D (depression, under 39 mph), S (tropical storm, 39–73 mph), H (hurricane, 74–110 mph) and M (major hurricane, over 110 mph). Our guide to tropical depressions, storms and hurricanes explains those stages.
- The cone itself: the area the center is likely to stay within.
- Tropical storm and hurricane watches and warnings in effect.
The map changed for the 2026 season. NHC made its cone with inland watches and warnings operational after testing it in 2024 and 2025. It now shows all land-based tropical storm and hurricane watches and warnings, coastal and inland, for the continental United States, Hawaii, Puerto Rico and the U.S. Virgin Islands. The whole 5-day cone has one shade; older versions drew days 1–3 in solid white and days 4–5 stippled. Diagonal pink and blue lines mark areas where a hurricane watch and a tropical storm warning are both in effect. In rare cases, NHC may post a preliminary cone with only coastal watches and warnings until the full version is ready.
How does NHC decide the size of the cone?
NHC places imaginary circles along the forecast track at 12, 24, 36, 48, 60, 72, 96 and 120 hours and draws the cone around them. Each circle is sized so that two-thirds of NHC’s official forecast errors over the previous five years fall inside it. For 2026, that sample is 2021–2025. NHC has used the 67th percentile of five years of errors since 2007. When the cone debuted in 2002, the circles were based on average errors over the previous 10 years.
Errors grow with time, so the circles grow too. These are NHC’s 2026 circle radii:
| Forecast hour | Atlantic (nautical miles) | Atlantic (about statute miles) | Eastern and central North Pacific (nautical miles) |
|---|---|---|---|
| 12 | 25 | 29 | 25 |
| 24 | 39 | 45 | 37 |
| 36 | 49 | 56 | 48 |
| 48 | 62 | 71 | 56 |
| 60 | 77 | 89 | 66 |
| 72 | 95 | 109 | 78 |
| 96 | 134 | 154 | 106 |
| 120 | 200 | 230 | 138 |
Source: NHC, Definition of the Track Forecast Cone. Statute miles are converted from nautical miles (1 nautical mile is about 1.15 statute miles). The figures are radii, so the Atlantic cone is about 400 nautical miles wide at 120 hours. NHC says the 2026 Atlantic cone is about 4–8% smaller than in 2025, and the eastern North Pacific cone about 3–8% smaller.
What does the cone not show?
The cone follows the center only. NHC’s map legend says a tropical cyclone is not a point and that its effects can span many hundreds of miles from the center. The cone does not show:
- Storm size. NHC says hurricane-force and tropical-storm-force winds can extend well beyond the cone.
- Storm surge. NHC lists storm intensity, forward speed, size, angle of approach to the coast and the shape of the continental shelf as factors in surge. The cone shows none of them.
- Rain and tornadoes. The National Weather Service notes that areas well outside the cone often experience tornadoes or inland flooding from heavy rain.
- Every possible track. If the full 5-day path of the center stays inside 60–70% of the time, the center leaves the cone at some point in the other 30–40% of cases.
Which NHC maps show wind, surge and rain?
NHC publishes a separate product for each hazard, described in its guide to graphical products:
- Wind Speed Probabilities: the chance that sustained winds of 34 knots (39 mph), 50 knots (58 mph) or 64 knots (74 mph) reach a location over periods out to 120 hours. NHC cautions that small percentages can still matter.
- Arrival time of tropical-storm-force winds: the Earliest Reasonable Arrival Time is the time before which there is no more than a 1-in-10 chance that those winds begin. The Most Likely Arrival Time is the time when arrival is equally likely before or after.
- Storm Surge Watch/Warning graphic: areas where life-threatening inundation is possible (watch, generally within 48 hours) or expected (warning, generally within 36 hours).
- Peak Storm Surge graphic: forecast ranges of how high water could reach above normally dry ground along the coast.
- Potential Storm Surge Flooding Map: flood depths with a 10 percent chance of being exceeded, which NHC calls a reasonable worst-case scenario. It usually first appears about 48 hours before hazardous conditions.
- Key Messages: NHC’s main points about hazards and uncertainty, which can include Weather Prediction Center rainfall graphics.
Local National Weather Service offices add Hurricane Local Statements and threat graphics for wind, storm surge, flooding rain and tornadoes in their areas.
What is NHC’s experimental cone?
In 2026, NHC began posting an experimental cone alongside the operational one. It replaces circles with ellipses that account for errors in both the storm’s speed (along-track) and its direction (cross-track). The ellipses use the 90th percentile of those errors over the previous five years, so the center would be expected to fall inside each ellipse 90% of the time. NHC describes the result as the likely track area of the center. The National Weather Service is taking public comments on it through November 30, 2026.
How often is the cone updated?
NHC posts a new cone with each full advisory and each intermediate advisory. In the Atlantic, full advisories normally come every six hours, at 5 and 11 a.m. and p.m. EDT. Intermediate public advisories follow every three hours when coastal watches or warnings are in effect. Our live list of active NHC storms shows the latest official advisory data in one place.
Bottom line
Read the cone as a map of where the center will probably go. For what your area may face, check NHC’s wind, surge and arrival-time maps, alerts from your local NWS office, and our guide to hurricane watches and warnings. NHC advises everyone, including people outside highlighted storm surge areas, to follow evacuation orders from local officials.
FAQ
Am I in the clear if I live outside the cone?
The cone cannot tell you that. NHC says hurricane-force and tropical-storm-force winds can extend well beyond it, and the NWS says areas well outside often get tornadoes or inland flooding. Check active NWS alerts for your state and your local NWS office.
Why does the cone get wider farther out?
Forecast errors grow with lead time. In 2026, the Atlantic circle radius is 25 nautical miles at 12 hours and 200 nautical miles at 120 hours.
Why is the Pacific cone narrower than the Atlantic cone?
Each basin’s circles come from that basin’s own past errors. NHC’s 2026 radii for the eastern and central North Pacific are smaller at most lead times, reaching 138 nautical miles at 120 hours compared with 200 in the Atlantic.
Does the cone show inland warnings now?
Yes. Since the 2026 season, NHC’s operational cone shows inland as well as coastal tropical storm and hurricane watches and warnings for the United States. Our guide to watch vs warning vs advisory explains how the NWS uses those words.