Adrian (2011)

A low pressure area formed about 365 nautical miles (n mi) south of Acapulco, Mexico, late on 7 June 2011 and became a tropical depression around 1200 UTC that day. It strengthened to Tropical Storm Adrian 12 hours later and moved west-northwestward, paralleling the southwestern coast of Mexico. Adrian underwent a roughly 48-hour period of rapid strengthening from 9–10 June, turned more westward after peak intensity, then moved over much colder water and weakened quickly, becoming a post-tropical low by 1200 UTC 12 June and dissipating by 12 June–14 June as a remnant trough.

Adrian did not make any landfalls on Mexico. Tropical storm watches were issued for the coast from Acapulco to Punta San Telmo on 8 June and discontinued the next day, and no tropical-storm-force winds were observed along the Mexican coast.

Maximum analyzed intensity was 120 knots (140 mph) between 0000 and 1200 UTC 10 June, with a minimum central pressure of 944 mb. At peak strength Adrian was equivalent to a Category 4 hurricane on the Saffir–Simpson scale.

No storm surge impacts were reported in the NHC report, and there were no specific rainfall totals or surge heights listed for Mexican cities or counties associated with Adrian. Coastal observations did not record tropical-storm-force winds, and the storm remained largely offshore while intensifying and then weakening over open water.

There were no reports of damage or casualties—no confirmed direct or indirect deaths—in association with Adrian. Noteworthy aspects include Adrian’s rapid intensification to an annular Category 4 hurricane over warm waters and its unusually fast weakening after crossing a sharp sea-surface temperature gradient. Forecasts of Adrian’s genesis were successful, but track and intensity forecasts showed larger-than-average errors because of the storm’s rapid changes; some numerical models performed better than the official forecast at various times.