1966 Pacific hurricane season

Seven hurricanes at the same peak

The archive follows 14 systems from 20 June to 19 October; 13 reached tropical storm strength and one September system has no recorded wind. Seven became hurricanes, and all seven share a 75 kt peak, while every tropical storm that stopped short shares a 45 kt peak. Those uniform values show how coarse the intensity estimates of the 1960s were. Accumulated cyclone energy came to 61.0.

Longer lists of the season run higher because they include every numbered depression, among them a system the Joint Hurricane Warning Center numbered Twenty-Two that passed 240 miles south of the island of Hawaii on 12 September and brought heavy rain to the islands. The site counts only systems that reached 34 kt during the tropical stage.

Blanca and Connie cross into the central Pacific

Hurricane Adele opened the season on 20 June south of Mexico, reached hurricane strength, turned west and came ashore west of Manzanillo on 24 June. It caused extensive damage in Mexico and no deaths. The next five hurricanes formed in quick succession through August.

Hurricane Blanca formed south of Mexico on 2 August, peaked on 5 August and weakened before crossing into the central Pacific as a depression. It regained storm strength and stair-stepped northwest until it dissipated northwest of Honolulu on 12 August. Blanca traveled 4,300 miles, then a record for a storm that formed in the eastern Pacific. Hurricane Connie followed a similar path, becoming a hurricane after it crossed into the central Pacific and fading south of Maui without reported damage.

Hurricanes Dolores and Eileen stayed at sea. Eileen strengthened quickly on 26 August, and the best track gives its minimum pressure as 990 mb; a ship crossed the hurricane that day without reported damage.

Francesca, Gretchen and Helga in September

Hurricane Francesca formed south of La Paz on 5 September and, at 252 recorded hours, became the longest-tracked storm of the year. Tropical Storm Gretchen formed close by on 7 September, and the two interacted: Francesca dove south and Gretchen never strengthened before losing its identity on 11 September. Francesca then looped east and degenerated on 16 September.

Hurricane Helga developed from a tropical wave on 9 September and peaked on 12 September. It had weakened to a tropical storm by the time it reached the Baja California Peninsula and dissipated over Chihuahua on 17 September. Helga caused one death in California, and waves from Helga and Francesca together eroded beaches along California and Baja California.

Kirsten, Lorraine and Maggie strike Mexico

Tropical Storm Kirsten brought the season's worst toll. It swept across Baja California Sur, crossed the Gulf of California and struck the mainland between Los Mochis and Ciudad Obregón with winds of about 50 kt. The storm killed at least eight people in Ciudad Obregón and destroyed more than 1,000 homes with floods and wind, with damage estimated at $5.6 million in 1966 dollars. Mexico's Defense Ministry supplied food, medicine and shelter in Sinaloa and Sonora.

Tropical Storm Lorraine came ashore west of Tecomán in early October and dissipated quickly. Tropical Storm Maggie followed in mid-October, soaking the same stretch of coast as it paralleled the shore, then moved inland near Manzanillo and again near Puerto Vallarta. Neither storm caused reported deaths or damage.

A new annual naming rotation

1966 was the first season in which the eastern Pacific name lists rotated by year, starting from the A name each season. Every name used came from the third of four sets introduced in 1960, so all were new. The set returned in 1970 with Kristen in place of Kirsten.