1971 Pacific hurricane season

The first year of full satellite coverage

1971 is generally treated as the first eastern Pacific season with reliable records, because it was the first year of continuous weather satellite coverage over the entire central Pacific. Accumulated cyclone energy came to 123.1 in the site's archive calculation, and the year ran from 21 May to 29 November.

The current best track counts 18 named storms, 12 hurricanes and 6 major hurricanes, then a record number of storms. The site also reaches 18 tropical storms and 12 hurricanes but only 5 major hurricanes, because the lists differ. Hurricane Olivia, the Pacific continuation of Atlantic Hurricane Irene, sits on the best-track list and not in this season's archive entries, while the site includes Hurricane Mary, which peaked at 80 kt in mid-July. The season also brought a then-record six landfalls.

Agatha and Bridget on the Guerrero coast

Hurricane Agatha formed south of Tehuantepec on 21 May and paralleled the coast. Air Force reconnaissance found an eye and, the next day, winds of 85 to 90 mph; a ship reported 100 mph on 24 May, the day of its 85 kt archive peak. Agatha came ashore as a Category 2 hurricane within 45 miles of Zihuatanejo. Up to half the homes in the village of Playa Azul were destroyed, along with much of the banana, mango and coconut crop.

Hurricane Bridget came from a tropical wave that left Africa on 3 June, crossed the Caribbean and Central America, and organized off El Salvador on 14 June. It reached 100 mph just southwest of Acapulco before weakening, then moved ashore on 17 June after running along the coast. Gusts reached 104 mph in Acapulco, tore off roofs and cut power to most of the city, and high tides destroyed 21 boats, among them the flagship of a Mexican Navy admiral. It killed 17 people and caused damage around Acapulco of 500 million pesos, or $40 million in 1971 dollars, the city's worst hurricane in at least 25 years.

Denise and a burst of hurricanes

Hurricane Denise organized on 2 July and became a hurricane on 6 July. Reconnaissance measured 951 mb on 8 July, and the storm peaked at 120 kt early on 9 July, the season's strongest one-minute wind in the archive. Its eyewall then broke down as it drew in cooler air, and Denise weakened to a tropical storm on its way toward Hawaii. The remnants passed south of the islands and brought rain heavy enough to cause minor flooding.

Between early July and early September, the basin produced one hurricane after another. Hurricane Francene deepened quickly to 100 kt on 19 July, then grew large enough to draw in cool surface air and weakened within a day. Hurricane Hilary, the longest-tracked storm at 288 recorded hours, held hurricane strength for a week before dying in the central Pacific. Hurricane Ilsa and Hurricane Monica both peaked at 100 kt, and neither reached land.

Katrina, Lily and Nanette

Tropical Storm Katrina, a very small storm, brushed Baja California Sur and came ashore in Sonora in August. Rain from its remnants ruined crops, destroyed railroad trestles and washed away three bridges. Hurricane Lily grew from the remnants of Atlantic Tropical Storm Chloe, deepened fast near the coast and made landfall soon after its peak. Lily caused 12 to 14 deaths in Mexico. Hurricane Nanette threatened southern Baja California in early September before turning west.

Priscilla weakens before Nayarit and Sinaloa

Hurricane Priscilla peaked at 110 kt on 10 October with a pressure of 951 mb, matching Denise's lowest reading. It weakened sharply before it came ashore south of Mazatlán as a tropical storm. Priscilla destroyed about 36,000 acres of corn, tomatoes, peppers, bananas and cotton, a loss of $3.12 million, and floods in 30 towns in Nayarit caused $544,000 in road damage, both in 1971 dollars.

Ramona and Sharon closed the year at sea, Sharon as a minimal tropical storm that dissipated on 29 November. The name Sharon was used for the first time.