Polo (2014)

Polo formed from a tropical wave and an elongated surface trough in the far eastern North Pacific and became a tropical storm at 0000 UTC on 16 September 2014 about 270 nautical miles south of Puerto Escondido, Mexico. It moved generally northwestward, tracking close to the Pacific coast of Mexico. Polo strengthened to a hurricane by 0000 UTC 18 September, then weakened back to a tropical storm later that day as its inner core was exposed by wind shear. The system weakened to a tropical depression by 0600 UTC 22 September about 200 nmi west of the southern tip of the Baja California peninsula, became a remnant low about six hours later, and finally dissipated well offshore on 26 September.

Polo did not make a direct landfall as a hurricane. Its closest approaches brought tropical-storm-force conditions near the coast of southwestern Mexico: the storm was about 115 nmi south-southwest of Manzanillo when it weakened from a hurricane to a tropical storm on 18 September, and it passed within roughly 75 nmi of the southern tip of the Baja California peninsula early on 21 September before turning away. Tropical storm watches and warnings were issued at various times for portions of the Guerrero, Michoacán, Colima, and Baja California Sur coasts.

The storm’s maximum sustained winds reached 65 knots (75 mph) during its peak beginning 0000 UTC 18 September, with a minimum central pressure estimated at 979 mb. Aircraft observations and a dropwindsonde later in the day indicated winds had diminished to about 55–60 kt (≈ 60–70 mph) as the storm weakened from its peak.

Large breaking waves and coastal surge affected the Guerrero coast and nearby areas. Reported coastal impacts included significant beach erosion and damage to shore structures in several municipalities of Guerrero; state officials estimated damage exceeding 100 million pesos (about $7.6 million US). Specific measured wind reports near the coast included a sustained 30 kt gusting to 40 kt at Manzanillo on 18 September and a gust to 35 kt at Isla María Madre on 20 September. The report did not list inland freshwater rainfall totals at individual cities in the NHC summary, though heavy rain and surf were noted along the Mexican Pacific coast.

Two deaths were associated with Polo. One man drowned in strong currents off an Acapulco beach, and two fishermen caught at sea by large waves left from Acapulco resulted in one fatality and one man later rescued in poor condition. The most serious damage was coastal — large waves and surge damaged or destroyed beachfront structures in Guerrero, which sustained the largest economic impact.

Noteworthy items: Polo’s formation was anticipated several days in advance in NHC outlooks, though actual formation occurred somewhat sooner than the earliest high-probability forecasts. NHC track forecasts for Polo were more accurate than 5‑year average errors and outperformed most individual models, though some multi‑model consensus guidance showed even lower track errors. Forecasts captured the storm’s relatively short-lived peak and subsequent steady weakening due to increasing wind shear.