How Hurricane Otis intensified on its approach to Acapulco

The strongest winds developed offshore

Table 1 puts Otis at 55 knots on the morning of 24 October UTC. The report estimates that the storm reached hurricane strength by 12:00 UTC and 100 knots by 18:00 UTC. The first 145-knot estimate came at 03:00 UTC the next day, 21 hours after the 55-knot estimate. Source 1 Source 2

Peak intensity and landfall are separate records

The NHC estimates maximum winds of 145 knots from 03:00 to 06:00 UTC. At 06:45 UTC it places the centre at 16.8°N, 99.9°W, with a landfall intensity of 140 knots and central pressure of 929 millibars. The chart’s landfall marker uses that record. Source 1 Source 2

How the centre and winds were reconstructed

The NHC combined satellite imagery and estimates with aircraft observations. A Hurricane Hunters flight provided two centre fixes on 24 October, and the report used satellite estimates for the peak near the coast. The published best track is the centre’s estimated position and intensity after reviewing those observations. Source 2

The storm weakened quickly inland

By 12:00 UTC on 25 October, the best track gives 85 knots and a central pressure of 980 millibars. At 18:00 UTC it gives 40 knots, placing Otis at tropical storm strength. The NHC reports that it dissipated later that day. Source 1 Source 2

Compare the measurements on their own terms

Wind and central pressure describe the whole storm’s estimated intensity at each time. The report lists ground-station observations separately. The map shows the centre’s path, while the station table in the report records conditions measured at particular places. Source 2 Source 1

Sources

• National Hurricane Center Hurricane Otis report, Table 1
• National Hurricane Center revised Hurricane Otis tropical cyclone report