Tropical cyclone analysis for the Northeast Pacific basin.
Accumulated Cyclone Energy (ACE) measures the total energy released by tropical cyclones during a season. It's the sum of a storm's sustained wind speed squared, taken every six hours while the storm is at tropical-storm strength or stronger.
The blue bands show the statistical envelope of the last 30 years: the outer band is every season's min-to-max range, the middle band is the 10th–90th percentiles, and the inner band is the interquartile range (25th–75th percentile). The dashed cyan line is the 30-year climatological mean.
The solid amber line is the current season. The violet line is the prior season for reference. The ranking table on the right shows where the current year stands versus every other season at this same point in the calendar. Click any year in the table to overlay that season's trajectory on the chart in hot pink.
Historical and provisional track data come from NOAA NCEI's IBTrACS v04r01 dataset. During an active season, the current-season line is kept fresh from live NHC ATCF best-track files as soon as they're issued.