Changing Pressure-Wind Relationships for Tropical Cyclones in the North Atlantic and Northeastern Pacific

Using the National Hurricane Center's best track data, pressure-wind relationships within tropical cyclones are examined for 35 years in the North Atlantic Ocean and 26 years in the northeastern Pacific Ocean. In both ocean basins, statistically significant temporal trends exist, suggesting that storms of equal pressure have lower wind speeds today than in the past. Likewise, storms of equal wind speed have lower pressures today. Strong temporal changes in pressure-wind relationships exist among a wide range of storm strengths in the Atlantic but only for weaker storms in the Pacific. An examination of surface pressure anomalies across the two ocean basins reveals that a shifting pressure gradient is likely responsible for these observations, possibly due to macroscale pattern changes such as the North Atlantic Oscillation.