2008 Pacific hurricane season

Season overview

By storm count, 2008 in the eastern and central North Pacific was close to normal, but most of its storms were weak and short-lived. The archive records 19 tracked systems, of which 17 reached tropical storm strength, 7 became hurricanes and 2 reached major hurricane strength. That hurricane tally is below the 1971 to 2005 average of about eight, and the major hurricane tally is roughly half the average. Accumulated cyclone energy came to 83.8 units, which puts the season at about three quarters of the long-term median by that measure.

Forecasters saw a quieter year coming. Before the season, Mexico's national weather service called for 15 named storms, 7 hurricanes and 2 major hurricanes, and the US Climate Prediction Center rated a below-normal season as the most likely outcome. Both pointed to the 2007 to 2008 La Niña and a longer decline in eastern Pacific activity. The cold ocean anomalies faded in early summer, but the atmosphere kept a La Niña-like pattern that drove strong easterly wind shear across the basin, and sea surface temperatures were cooler than in recent years, though near the long-term average. Shear, dry air and cool water held back storm after storm in the NHC reports.

The archive's 17 tropical storms agree with the season total of 17 named storms, which counts 16 storms named in the eastern Pacific plus Tropical Storm Kika, which formed in the central Pacific. The two systems that never reached tropical storm strength were Tropical Depression Five-E and Tropical Depression Seventeen-E.

How the season unfolded

The season started early and far to the east. Tropical Storm Alma formed on 29 May off Costa Rica, farther east than any earlier eastern Pacific cyclone that had not crossed over from the Atlantic, and came ashore in Nicaragua the same day. After a gap of four weeks, Hurricane Boris and Tropical Storm Cristina both formed on 27 June. Boris became the season's first hurricane on 1 July and peaked at 70 kt far off southwestern Mexico.

July was the busiest stretch. Tropical Storm Douglas brushed the southwest coast of Mexico, and Tropical Depression Five-E moved ashore just west of Lázaro Cárdenas on 7 July. Three hurricanes followed in quick succession: Hurricane Elida peaked at 90 kt, Category 2, on 16 July; Hurricane Fausto passed between Clarion and Socorro islands at its 80 kt peak on 20 July; and Hurricane Genevieve struggled over water cooled by Fausto's wake before briefly reaching hurricane strength on 25 July. All three stayed at sea.

August brought the season's first major hurricane, Hernan, along with Tropical Storm Kika in the central Pacific and two weaker storms, Iselle and Julio. Activity then stalled. September produced only the short-lived Tropical Storm Karina and Tropical Storm Lowell, and its accumulated cyclone energy was about 9 percent of average, the quietest September since reliable records began in 1971.

October revived the season. Hurricane Marie formed on 1 October and peaked at 70 kt, Hurricane Norbert followed three days later, and Tropical Storm Odile ran parallel to the southern Mexican coast just offshore. Tropical Depression Seventeen-E came and went in late October. Tropical Storm Polo, the last system, formed on 2 November and had weakened by 5 November, the archive's last tropical-stage observation.

Strongest storms

Hurricane Norbert was the strongest storm of the season. It formed south of Acapulco on 4 October and took three days to become a hurricane. It then gained 40 kt in 24 hours and peaked at 115 kt, Category 4, with a pressure of 945 hPa at 18:00 UTC on 8 October, about 390 n mi south of Cabo San Lucas. NHC called it the strongest October hurricane in the eastern North Pacific since Kenna in 2002. An eyewall replacement brought it down to about 70 kt the next day. Norbert recovered to 100 kt by 11 October as it turned northeast toward Baja California.

The season's only other major hurricane, Hurricane Hernan, never threatened land. It formed from a tropical wave on 6 August far south-southwest of the Baja California peninsula, strengthened rapidly once shear eased, and peaked at 105 kt, Category 3, with a pressure of 956 hPa on 9 August. An eyewall replacement and cooler water then wore it down, and its remnant low dissipated southeast of the Island of Hawaii on 16 August. Hurricane Elida, at 90 kt, was the strongest of the five Category 1 and 2 hurricanes.

Landfalls and impacts

Tropical Storm Alma was the first eastern Pacific tropical storm or hurricane on record to make landfall on the Pacific coast of Central America. It came ashore just southwest of León, Nicaragua, on 29 May with winds near its 55 kt peak and dissipated over western Honduras the next day. Its rains, up to 14.82 in at Quepos, Costa Rica, damaged more than 1,000 homes and over 100 roads and bridges in Costa Rica, where losses were estimated at 33 million US dollars (2008 USD). NHC counted two direct deaths, a girl swept away in Honduras and a fisherman lost when a boat sank offshore, and seven indirect deaths. Five of the indirect deaths came in the runway accident of an airliner at Tegucigalpa, and two were electrocutions in Nicaragua. Nine people on fishing boats were still missing when the report was written.

Hurricane Norbert made the season's most damaging landfall. It struck near Puerto Chale, just southeast of Bahía Magdalena in Baja California Sur, around 16:30 UTC on 11 October with winds near 90 kt, Category 2, making it the strongest hurricane on record to hit the western coast of the Baja California peninsula. It crossed the Gulf of California and reached Sonora east-southeast of Huatabampo early on 12 October as a 75 kt Category 1 hurricane. NHC reports five direct deaths from river flooding in Alamos, Sonora. Media reports cited roof damage to nearly half the homes on the islands of Margarita and Magdalena and power cuts to about 20,000 homes in Baja California.

Two weaker storms also hit the southern Baja California peninsula. Tropical Storm Julio came ashore about 35 n mi west-southwest of La Paz on 25 August with winds near 40 kt, and NHC recorded one drowning near Mulegé. Tropical Storm Lowell reached Cabo San Lucas as a tropical depression on 11 September. Its remnants flooded Sonora and Sinaloa, leaving more than 26,500 people homeless, and the government of Sonora put damage in that state at 200 million pesos, about 15.5 million US dollars (2008 USD). Lowell's moisture later merged with a front over the central United States, where Chicago's O'Hare airport logged 6.64 in, its wettest day since records began in 1871.

Records and other context

Several of the season's storms had Atlantic origins. The remnant circulation of Alma drifted into the western Caribbean and helped form Atlantic Tropical Storm Arthur on 31 May. Going the other way, the tropical waves behind Julio, Karina and Lowell had already spawned Atlantic storms Fay, Gustav and Hanna before crossing into the Pacific.

Polo, the season's last storm, became a tropical storm at just 8.7°N. NHC records show only four other eastern North Pacific cyclones reaching tropical storm strength closer to the equator. Hurricane Marie had the longest recorded track in the archive, 438 hours, but it was a tropical cyclone for only six of those days. Its remnant low meandered for nearly two weeks before merging into the Intertropical Convergence Zone on 19 October. No eastern Pacific cyclone crossed 140°W into the central Pacific while still tropical, the first season without such a crossing since 1996.