Major Hurricane Roslyn Nears West Coast of Mexico

Major Hurricane Roslyn neared the west coast of Mexico on Saturday night. At 11:00 p.m. EDT on Saturday the center of Hurricane Roslyn was located at latitude 20.0°N and longitude 106.6°W which put it about 65 miles (105 km) west-southwest of Cabo Corrientes, Mexico. Roslyn was moving toward the north at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 954 mb.

A Hurricane Warning was in effect for Las Islas Marias. A Hurricane Warning was also in effect for the portion of the coast from Playa Perula to Escuinapa, Mexico. The Hurricane Warning included Puerto Vallarta. A Hurricane Watch was in effect for the portion of the coast from Escuinapa to Mazatlan, Mexico. Tropical Storm Warnings were in effect for the portions of the coast from Manzanillo to Playa Perula, Mexico and from Escuinapa to Mazatlan, Mexico.

Hurricane Roslyn was at Category 4 intensity on the Saffir-Simpson Scale as it approached the west coast of Mexico on Saturday night. A circular eye with a diameter of 10 miles (16 km) was at the center of Roslyn’s circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Roslyn. Storms near the core generated upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane Roslyn was small. Winds to hurricane force extended out 30 miles (50 km) from the center of Roslyn’s circulation. Winds to tropical storm force extended out 80 miles (130 km) from the center of circulation. The Hurricane Intensity Index (HII) was 25.1. The Hurricane Size Index (HSI) was 8.5 and the Hurricane Wind Intensity Size Index (HWISI) was 33.6. Hurricane Roslyn was capable of causing localized severe damage.

Hurricane Roslyn will into an environment that will become unfavorable for intensification during the next few hours. Roslyn will move over water where the Sea Surface Temperatures are near 29˚C. However, an upper level trough west of Baja California will produce southwesterly winds that will blow toward the top of Roslyn’s circulation. Those winds will cause the vertical wind shear to increase. Hurricane Roslyn could start to weaken when the wind shear increases.

The upper level trough west of Baja California will steer Hurricane Roslyn toward the northeast during Sunday. On its anticipated track Hurricane Roslyn will make landfall on the west coast of Mexico near San Blas on Sunday morning. Although Roslyn could weaken before it makes landfall, it is likely to still be a major hurricane when it reaches the west coast of Mexico. Roslyn will bring strong gusty winds and locally heavy rain to Nayarit. Heavy rain could cause flash floods in some locations. Hurricane Roslyn could cause a storm surge of up to 13 feet (4 meters) along the coast. Hurricane Roslyn will be capable of causing localized major damage.