Hurricane Patricia

Pre-Landfall 1 | Summary
Posting Date: October 23, 2015, 1:00:00 PM

Hurricane Patricia became the most powerful tropical cyclone ever measured in the Western Hemisphere on Friday morning when its maximum sustained winds reached a record-breaking strength of 200 mph (325 km/h). With a minimum central pressure of 879 mb, it also now holds the record for the lowest pressure of any hurricane on record, passing Hurricane Wilma’s 882 mb in 2005. The intensification rate of Hurricane Patricia is also extremely impressive, having increased an estimated 100 mph in just 24 hours. Only Hurricane Linda of 1997 intensified at this rate within the satellite era.

Meteorological Summary

Patricia rapidly intensified from a tropical storm to a Category 5 hurricane in the past 24 hours. Currently located at 18.2°N, 105.3°W, about 85 miles (135 km) southwest of Manzanillo, Mexico, a turn toward the north-northeast is expected later Friday with increasing forward motion. Landfall is forecast to occur Friday afternoon or evening between north of Puerto Vallarta and south of Manzanillo.

Category 5 winds are presently occurring over a very small area, about 15 miles across, near the center of Hurricane Patricia, though hurricane-force winds extend outward up to 35 miles (55 km) from the center and tropical storm force winds extend outward up to 175 miles (280 km). Sea surface temperatures are 30-31°C in the vicinity of Patricia, which is several degrees above normal, and ocean heat content—which takes into account how deep warm water extends—is also above normal. These are both typical of a strong El Niño event for this area. 

The center of Patricia is expected to move quickly north-northeastward across western and northern Mexico after landfall, with the mountainous terrain contributing to rapid weakening.

Forecast Conditions

Locations within the hurricane warning area should begin experiencing hurricane conditions during the next several hours, with the worst conditions Friday evening. Tropical storm conditions are already impacting some areas. Damaging winds are expected from Patricia making landfall as a Category 5 hurricane. Total rainfall accumulations of 8−12 inches are anticipated, reaching up to 20 inches in the Mexican states of Nayarit, Jalisco, Colima, Michoacan, and Guerrero through Saturday, meaning the threatened costal region could receive up to 40% of its average annual rainfall in 48 hours. Massive waves of up to 39 feet (12 meters) may occur near the landfall point, contributing to already significant storm surge expectations that will likely cause coastal flooding.

Emergency Preparations

Mexican authorities have declared emergencies in the three coastal states of Jalisco, Nayarit, and Colima. Schools have been closed and residents are being told to take precautions, including stocking up on supplies, boarding up homes, and moving to higher ground. Evacuations of the resorts in Puerto Vallarta are underway.

Exposure at Risk

Predominant construction types for insured residential buildings are masonry and concrete. Most have concrete and masonry slab roofs. Masonry buildings can better resist the wind uplift load than wood frame buildings, due to their mass. Within masonry construction, confined masonry is the most popular construction practice in Mexico and performs better than plain masonry under lateral wind loads. An estimated 50% of new homes built in Mexico each year are constructed without a building permit, making residential exposures inconsistent and difficult to track. Commercial building stock is quite heterogeneous and varies from poorly constructed low-rise masonry structures to well-maintained steel buildings. Concrete and masonry are the main construction types. Wind damage is usually restricted to non-structural components such as windows and wall sidings.

In a Category 5 hurricane, many non-engineered and poorly built structures will be destroyed or damaged beyond repair. Wind-borne debris in the hurricane wind field is expected to cause significant nonstructural damage to roof and wall claddings of engineered structures, some of which will experience structural damage beyond repair. Widespread power and communication disruptions are expected from downed trees and utility poles. In addition to wind damage, exposures may be susceptible to damage from flooding, storm surge, and mudslides expected from Hurricane Patricia, especially along the coast.

Insurance Impacts

Residential take-up rates in Mexico are low, while commercial take-up rates are significant. Industry impacts will depend on the direction and intensity of Hurricane Patricia at landfall, as well as duration post-landfall, and attention should be paid to the major resort city of Puerto Vallarta and second-largest Mexican city of Guadalajara.

The last similar storm to strike near Puerto Vallarta was Hurricane Kenna, a Category 5 hurricane that made landfall in 2002, which caused approximately USD 100 million in damage. Hurricane Odile made landfall as a Category 3 storm in 2014 near the prime tourist destination of Cabo San Lucas, located on Mexico’s southern Baja California peninsula, and caused more than USD 1 billion in insured losses.

Pre-Landfall 1 | Downloads
Posting Date: October 23, 2015, 1:00:00 PM