Puerto Vallarta is under a hurricane watch

Roslyn looks better organized on satellite imagery this evening and Puerto Vallarta has been placed under a hurricane watch.

A Hurricane Watch means that hurricane conditions are possible within the watch area. A watch is typically issued 48 hours before the anticipated first occurrence of tropical-storm-force winds, conditions that make outside preparations difficult or dangerous.

The cyclone will move over warm sea surface temperatures within a weak deep-layer shear environment during the next couple of days or so. This is expected to support strengthening, and Roslyn is forecast to become a hurricane by late Friday with continued intensification over the weekend.

Key Messages:

1. Roslyn is forecast to become a hurricane before it passes near or over the west-central coast of Mexico late Saturday and Sunday, accompanied by strong winds and a potentially dangerous storm surge. A Hurricane Watch has been issued for the coast of mainland Mexico from Playa Perula northward to San Blas, and additional watches or warnings will likely be required on Friday.
2. Heavy rainfall could lead to flash flooding and possible landslides in areas of rugged terrain over coastal southwestern and west-central Mexico.