Beatriz (2011)

A low-pressure area formed from interacting tropical waves south-southeast of Acapulco, Mexico, and became a tropical depression by about 0600 UTC on 19 June 2011 roughly 225 nautical miles south-southeast of Acapulco. The system moved generally west-northwest to northwest, strengthening to Tropical Storm Beatriz on 19 June and to a hurricane by about 1800 UTC 20 June as it approached the southwestern Mexican coast. The storm reached its peak near the coast early on 21 June, then turned westward, weakened quickly after interacting with coastal terrain, and dissipated by 0600 UTC 22 June about 75 nautical miles west of Manzanillo.

Beatriz’s closest approach to land occurred on 21 June when its eye passed within about 15 nautical miles of the coast between 0600 and 0900 UTC. Because part of the coast fell within the hurricane’s strike circle, the event is counted as a hurricane strike on the southwestern Mexican coast; sustained hurricane-force winds likely affected a small portion of the coast near Manzanillo. There are no definitive surface reports showing widespread tropical-storm-force winds on land.

The storm’s maximum sustained winds peaked at 80 knots (about 92 mph) with a minimum central pressure of 977 mb around 0600 UTC on 21 June, making Beatriz a Category 1 hurricane at its strongest. Aircraft reconnaissance measured flight-level winds of 74–76 kt and SFMR surface estimates near 70 kt during the intensification phase; satellite estimates supported the 80-kt peak.

Heavy rain and rough seas affected coastal states from Guerrero to Jalisco. Reported rainfall totals included 222.5 mm (8.76 in) at Copala, Guerrero; 167.5 mm (6.59 in) at Lázaro Cárdenas, Michoacán; and 159 mm (6.26 in) at Callejones, Colima. Media accounts described severe flooding in parts of Acapulco. No specific storm surge measurements on the coast were reported in the observations included in the report.

There was one direct fatality when a teenage boy was swept away by a rapidly rising stream related to the heavy rains. Three additional deaths in the Acapulco municipality of Amatillo were considered indirect: a father and son drowned while trying to rescue a family member who fell through boards covering a septic tank, and the mother also drowned. Damage descriptions focused on flooded homes, uprooted trees, and washed-out roads in coastal communities.

Noteworthy items: the storm formed from a complicated interaction of multiple tropical waves and a Kelvin wave, and its genesis was well forecast with increasing probabilities in the days before formation. NHC track forecasts were generally better than recent averages, especially at 48 hours, but intensity forecasts had larger errors than recent averages — forecasters anticipated the rapid intensification but did not fully anticipate the equally rapid weakening caused by interaction with the Sierra Madre del Sur.