Mexico: Hurricane Olaf tracking northwestward off the southwestern coast of Baja California Sur State early Sept. 10. /update 1

Event

Hurricane Olaf is tracking northwestward in the North Pacific Ocean, just off the southwestern coast of Baja California Sur State, Mexico, early Sept. 10 following landfall near San Jose del Cabo, late Sept. 9. As of 03:00 MDT, the system's center of circulation was approximately 70 km (45 miles) southwest of La Paz, Baja California Sur State, Mexico. Forecast models indicate that Olaf will weaken as it tracks northwestward, closely following Baja California Sur State's southwestern coast through the afternoon of Sept. 10. The storm is forecast to weaken into a tropical storm as it turns to track west, away from land later that day. The storm will transition into a post-tropical cyclone early Sept. 12 and dissipate in the North Pacific Ocean early Sept. 15. Some uncertainty remains in the track and intensity forecast, and significant changes could occur in the coming days.

Government Advisories
As of 03:00 MDT Sept. 10, the Mexican Meteorological Service has issued the following watches and warnings:

• Hurricane Warning: Baja California Sur, Mexico, from Todos Santos to Cabo San Lazaro.

• Tropical Storm Warning: Baja California Sur, Mexico, from north of Cabo San Lazaro to Puerto San Andresito as well as south of Todos Santos and south of Loreto.

Hazardous Conditions
Hurricane Olaf will likely bring heavy rainfall, strong winds, and rough seas to coastal areas in southern Baja California Sur through Sept. 11. Sustained heavy rainfall could trigger flooding in low-lying communities near streams, creeks, rivers, and urban areas with easily overwhelmed stormwater drainage systems.

Sites located downstream of large reservoirs could experience flash flooding after relatively short periods of intense rainfall. Forecast models indicate that heavy rainfall is possible over portions of far southern Baja California Sur, with 13-25 cm (5-10 inches) of rain forecast through Sept. 10. Flooding could isolate some communities for several days.

Prolonged sea swells and storm surge generated by the system will likely result in coastal flooding as the system approaches land. Persistent onshore flow could make it difficult for surge to recede and for water levels to decrease in coastal river catchments. In addition to the heavy rain, flooding, and storm surge, Hurricane Olaf could produce damaging wind gusts, resulting in power outages due to uprooted trees and toppled utility lines. Swells due to Olaf are likely to continue affecting portions of the coastal areas of southern Baja California Sur, Nayarit, and Sinaloa states through Sept. 11.

Transport
Inclement weather associated with the storm could trigger localized business, transport, and utility disruptions. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Areal flooding in urban locations could also result in severe traffic congestion, while strong winds will pose a hazard to high-profile vehicles. Heavy rain and low visibility may trigger flight disruptions at regional airports. As of late Sept. 9, the Cabo San Lucas and San Jose del Cabo ports are closed. Authorities have confirmed at least 37 domestic and international flights have been canceled at Los Cabos (SJD) and La Paz (LPB) airports due to Olaf.

Disruptions triggered by inclement weather and resultant hazards, such as flooding could persist well after conditions have improved. If there is severe damage to infrastructure, repair or reconstruction efforts may exacerbate residual disruptions.

Health
Stagnant pools of water during and after flooding increase the incidence of insect- and waterborne diseases, such as dengue fever, cholera, and malaria. The threat of these disease outbreaks is usually elevated in the low-income or underdeveloped areas of major urban centers due to the presence of incomplete or open sewer lines. The latent threat of waterborne contaminants from inundated industrial sites cannot be discounted; exposure to raw sewage and other hazardous materials mixed with floodwaters poses a serious health threat.

Advice

Activate contingency plans in areas where officials forecast hurricane or tropical storm conditions. Heed all evacuation orders. Use extreme caution in low-lying coastal areas and near streams, creeks, and other waterways due to the high potential for severe flooding and storm surge.

Stockpile water, batteries, and other essentials in advance. Charge battery-powered devices when electricity is available; restrict the use of cellular phones to emergencies only. Power down mobile devices when not in use. Keep important documents in waterproof containers. Observe strict food and water precautions, as municipalities could issue boil water advisories following flooding events. Take precautions against insect- and waterborne diseases in the coming days. Keep any necessary medications in a waterproof container.

Plan accordingly for protracted commercial, transport, and logistics disruptions in areas in the path of the storm, especially if vital infrastructure is damaged. Seek updated information on road conditions before driving or routing shipments through areas where flooding has occurred. Confirm flights before checking out of hotels or driving to the airport; clearing passenger backlogs may take several days in some locations.

Resources

US National Hurricane Center
National Weather Service
Mexican Meteorological Service (Spanish)