2013 Pacific hurricane season

Many storms, little power

By storm count 2013 ran slightly ahead of the 1981 to 2010 average of about 15 named storms and 8 hurricanes, but it fell well short on intensity. Only one hurricane reached major strength against a long-term average of nearly four, and the accumulated cyclone energy of 78.3 units was modest for the basin, because most systems were weak, compact or short-lived. Of the ten hurricanes, eight peaked at Category 1.

Forecasters had expected a quiet year. In May the Climate Prediction Center called for a below-normal eastern Pacific season of 11 to 16 named storms, citing near or below average sea surface temperatures in the eastern equatorial Pacific and the multi-decade era of low eastern Pacific activity that began in 1995. The Central Pacific Hurricane Center likewise expected one to three cyclones in its region under neutral El Niño conditions. The count of named storms beat those outlooks, while the energy of the season stayed low.

The site's figures and the counts in NHC summaries and Wikipedia differ by definition. The site counts storms with US-agency one-minute winds of 34 kt or more during the tropical stage across each storm's whole track, which gives 20 tropical storms and 10 hurricanes. Wikipedia lists 9 hurricanes because it counts only intensity reached east of the International Date Line; Pewa reached 65 kt in the Central Pacific Hurricane Center's best track only after crossing into the western Pacific, where it was classed as a typhoon. The Colorado State University energy total of 74.8 units, built from NHC best-track data for the basin, differs from the site's 78.3 because it comes from a different dataset and counts only the basin's own portion of each track.

How the season unfolded

The season opened on time. Tropical Storm Alvin formed on 15 May, the first day of the eastern Pacific season, at an unusually low latitude near 8°N, and Hurricane Barbara followed at the end of the month, making 2013 one of only a handful of years since 1949 with two tropical storms in May. Late June and early July brought a quick run of three hurricanes, Cosme, Dalila and Erick, all of them Category 1 storms that stayed off the Mexican coast or merely grazed it.

The busiest stretch ran from late July to early September. Tropical Storm Flossie crossed into the central Pacific and weakened near Hawaii, Hurricanes Gil and Henriette tracked far out to sea, and in mid-August a persistent trough south of Hawaii produced three central Pacific cyclones in about three days: Pewa, Unala and an unnamed depression. Pewa was the first cyclone to form in the central Pacific since Tropical Storm Omeka in December 2010. Tropical Storms Ivo and Juliette then approached Baja California, and Hurricane Kiko briefly reached hurricane strength well offshore.

September was dominated by Tropical Storm Lorena and then by Hurricane Manuel, the deadliest system of the year. A lull of nearly three weeks followed before Tropical Storm Narda formed on 6 October, and Tropical Storms Octave and Priscilla developed within a day of each other in mid-October. Hurricane Raymond arrived late in the month, and Tropical Storm Sonia, which formed on 1 November, closed the season with a landfall in Sinaloa on 4 November.

Raymond and the strongest storms

Hurricane Raymond was the season's only major hurricane and its strongest, longest-lived storm. It formed south-southwest of Acapulco on 20 October and, over water near 30°C with little shear, went from a 30 kt depression to a 110 kt Category 3 hurricane in 42 hours, peaking at 18:00 UTC on 21 October about 80 nautical miles south-southwest of Zihuatanejo with a minimum pressure of 951 hPa.

Raymond then stalled and made a small clockwise loop off the Guerrero coast. Stirring up the shallow warm layer, it cooled the sea beneath it from about 30°C to about 24°C, and together with rising shear this made it weaken almost as fast as it had strengthened, to a tropical storm by 23 October. Moving west into calmer conditions, it intensified again into a hurricane on 27 October and reached a secondary peak of 90 kt before shear finished it southwest of Baja California on 30 October.

The next strongest storm was Hurricane Henriette, which unexpectedly reached 90 kt, Category 2, on 8 August far out over open water before weakening on its way toward the central Pacific. Every other hurricane of the season peaked between 65 and 75 kt.

Landfalls and impacts

Hurricane Manuel caused the season's worst disaster. It came ashore in Michoacán as a 60 kt tropical storm on 15 September, and its torrential rain set off flash floods and mudslides across southwestern Mexico, especially in Guerrero, where a landslide destroyed nearly half the village of La Pintada. Its remnants then reorganized over the Gulf of California, and Manuel became a hurricane and made a second landfall just west of Culiacán on 19 September. NHC's revised report attributes 123 deaths in Mexico to Manuel, at least 104 of them direct, and cites an estimated total economic impact of about US$4.2 billion (2013 dollars), with insured losses estimated at US$200 to 685 million.

Hurricane Barbara made landfall about 15 nautical miles west-southwest of Tonalá, near the Oaxaca and Chiapas border, at 70 kt on 29 May. NHC counted three direct deaths in Mexico, one of them a surfer who drowned in rough surf near Puerto Escondido. A Mexican government disaster assessment cited by Wikipedia put total losses at 1.89 billion pesos, about US$148 million (2013 dollars).

Other storms brought lesser but real harm. Hurricane Erick, whose center stayed offshore, was blamed for two direct deaths in river flooding in Nayarit. Moisture from Tropical Storm Ivo flooded Loreto in Baja California Sur, then spread into the southwestern United States, where one indirect death occurred in San Bernardino County, California, and damage in the Las Vegas area was estimated at no less than US$300,000 (2013 dollars). Tropical Storm Juliette's winds downed trees and power lines around Cabo San Lucas, and a man was electrocuted there, which NHC counts as an indirect death.

Later in the season, Tropical Storm Octave made landfall just north of Cabo San Lázaro in Baja California Sur on 15 October with 40 kt winds, and Tropical Storm Sonia came ashore near El Dorado, Sinaloa, on 4 November, where NHC attributes two direct deaths to it, a missing fisherman and a lightning victim in Nayarit. Hurricane Raymond never made landfall and caused no reported deaths, but its rain renewed flooding in parts of Guerrero still recovering from Manuel. Tropical Storm Flossie brought tropical storm watches and warnings to Hawaii, its winds and lightning cut power to more than 10,000 homes on Maui and the Big Island, and a Maui man was injured when lightning struck his house.

Records and a retired name

Several storms set benchmarks. Barbara's landfall point is the easternmost recorded for an eastern Pacific hurricane, and its 29 May landfall is the second earliest hurricane landfall in the basin since records began in 1949. Manuel became the first eastern Pacific cyclone on record to make landfall on mainland Mexico, regenerate over water and then go on to become a hurricane. Flossie's watches were the first issued for the main Hawaiian Islands since Tropical Storm Felicia in 2009.

Because of the deaths and damage Manuel caused, the World Meteorological Organization retired the name in April 2014, and Mario took its place on the list from 2019. The eastern Pacific season used the names Alvin through Sonia, the same list as in 2007, while Pewa and Unala came from the central Pacific rotation.