Alvin (2013)

A tropical wave that moved westward from northeastern South America developed into a broad low in the eastern North Pacific and became a tropical depression on 15 May 2013 about 565 nautical miles south-southwest of Acapulco, Mexico. It strengthened into Tropical Storm Alvin later that day, moved generally west-northwest around the southern edge of a subtropical ridge, reached peak strength on 16 May, and then weakened and opened into a trough before dissipating by 17 May about 675 nmi southwest of Manzanillo, Mexico. Alvin remained well offshore during its entire life.

There were no landfalls associated with Alvin. The storm formed and stayed over open ocean, so no coastal watches or warnings were issued and no coastal locations experienced Alvin as a direct landfalling system.

Alvin’s peak intensity was 50 knots (about 58 mph) with an estimated minimum central pressure of 1000 millibars, reached around 0600 UTC on 16 May 2013. At that time the cyclone was located roughly 625 nmi south-southwest of Manzanillo. Its analyzed peak corresponds to a moderate tropical storm, not a hurricane.

Because Alvin stayed far from land, there were no reports of storm surge impacts or rainfall totals associated with the cyclone in coastal cities or counties. No ship reports of tropical-storm-force winds were received, and no specific surge heights or rainfall amounts were recorded in populated locations.

There were no reported deaths or damage from Alvin. Noteworthy aspects of the storm include its very low latitude of formation (7.8° N), tying it for the second-lowest latitude tropical cyclone formation in the eastern North Pacific during the satellite era, and that it formed slightly before the official start of the eastern North Pacific season. Forecasts of its genesis were issued in advance, but official track and intensity forecast errors were larger than recent 5-year means, in part because the storm was short-lived and small.