Alvin (2019)

A compact tropical cyclone formed from a tropical wave that crossed Central America in late June 2019 and became a tropical depression at 1200 UTC 25 June about 300 miles south of Manzanillo, Mexico. The system moved generally west to northwest over the next several days, becoming Tropical Storm Alvin at 1200 UTC 26 June and turning more northwestward as it progressed. Alvin intensified into a hurricane at 0000 UTC 28 June while located about 450 nautical miles southwest of the southern tip of the Baja California peninsula, then weakened back to a tropical storm by 0600 UTC 28 June and degraded to a remnant low by 0600 UTC 29 June. The remnant low dissipated on 30 June.

Alvin remained well offshore of the Mexican coast for its entire life; no coastal watches or warnings were issued and the cyclone did not make any landfalls.

The storm’s peak intensity occurred at 0000 UTC 28 June with maximum sustained winds estimated at 65 knots (75 mph) and a minimum central pressure of 992 mb, making it a minimal Category 1 hurricane at its strongest. Alvin was small in size; satellite scatterometer data showed the largest extent of tropical-storm-force winds was about 60 nautical miles from the center.

There were no reported storm surge measurements or significant rainfall totals attributed to Alvin in coastal cities or counties. Observations and satellite data were used to track the system, but the report lists no specific surge heights or heavy-rainfall accumulations at named locations.

No damage or casualties were reported in association with Alvin. Forecasts of its formation were generally successful, with the Tropical Weather Outlook raising genesis probabilities from low to high in the days before development. Track forecast errors were larger than recent averages through 48–72 hours, partly because the cyclone’s center reformed southwestward on 26 June, which was not well anticipated; intensity forecasts were reasonably accurate at short lead times.