2010 Pacific Hurricane Season - Seasonal Summary

Seasonal Summary

Coinciding with pre-season forecasts, the 2010 season was unusually quiet. However, it was less active than predicted as well, with a record low of eight named storms forming. There was also a record-late December system, Tropical Storm Omeka, in the Central Pacific Hurricane Center's (CPHC) area of responsibility, though it was not factored in to the National Hurricane Center's (NHC) area of responsibly total. Initially, the season began with record-high activity, featuring two major hurricanes in June. Accumulated Cyclone Energy (ACE) values exceeded 300% of the long-term mean, though most was due to Category 5 Hurricane Celia. Hurricane Celia was also the second-earliest forming storm of that intensity during the course of a season, surpassed only by Hurricane Ava in 1973. The month featured an ACE value of 37.22, eclipsing the previous record set in 1984. However, this activity abruptly halted and languished throughout the month of July. During that month, only one tropical depression formed; this marked the first time since 1966 that no named storms formed in the basin during the month of July. However, due to the activity in June, the ACE value for the season by the start of August remained slightly above normal, roughly 107% the yearly mean. From July 1 to the end of the season, the basin observed record low activity, with only three named storms developing.

There were four tropical cyclones that impacted land in this season. The first was Tropical Storm Agatha, which brought catastrophic rainfall and flooding to Central America, especially Guatemala. Tens of thousands of structures were destroyed across four countries, leaving roughly $1.1 billion (2010 USD) in property damage and 317 fatalities. Tropical Depression Two-E caused only minor effects on land, bringing moderate rains and gusty winds to the Mexican state of Oaxaca. Tropical Depression 11-E caused a great deal of flooding in southern Mexico, causing millions of dollars in damage and causing over 50 deaths in areas of Oaxaca. And Tropical Storm Georgette made landfall in southern Baja California and Mainland Mexico, causing minor damage. Hurricane Celia became the first Category 5 hurricane of the season, and marked the first occasion when consecutive Pacific hurricane seasons had hurricanes of that intensity, following 2009's Hurricane Rick, and became only the second June Category 5 hurricane in the Eastern Pacific, after 1973's Ava. Hurricane Darby was the second major hurricane of the season, reaching Category 3 strength on June 25. This made Darby the earliest second major hurricane of a season, eclipsing 1978's Hurricane Daniel, which reached major hurricane status on June 30. However, after the very active June, there was a period of inactivity between July and early September, with only 2 named storms forming in the two-month period. September was the least active September since reliable records began in 1971 with the formation of only one tropical storm, Tropical Storm Georgette, which was partly due to the ongoing La Niña. There was a record low level of hurricanes and tropical storms. Initially, By the end of the season, the Central Pacific experienced no tropical cyclones; the last time this happened was in 1979.

By the official end of the season, the Pacific had produced a record low of eight named storm, tying the previous in 1977. In terms of ACE, the season was the third-quietest, only surpassed by the 2007 and 1977 seasons. Of this, roughly 70% was attributable to Hurricanes Celia and Darby. The record inactivity experienced in the Northeastern Pacific also took place in the Northwestern Pacific. Since reliable records began in the 1970s, there has been no precedent for both basins experiencing exceptionally low tropical cyclone formation. Moreover, this general lack of storm formation was reflected in all cyclone basins except the Atlantic. On average, the Northeastern Pacific accounts for 16 percent of the world's storms; however, during 2010, it accounted for roughly 10 percent (7 out of 67 cyclones).