Boris (2014)

A compact low pressure area south of the Mexico–Guatemala border organized into a tropical depression on June 2, 2014, about 170 nautical miles south of Tonalá, Mexico. The system moved generally northward and became Tropical Storm Boris on June 3. Boris reached peak strength later that day and then weakened as its deep convection moved over southern Mexico. The circulation stayed close to the coast of Chiapas, drifted northwestward over the Gulf of Tehuantepec, degenerated to a remnant low by the evening of June 4, and dissipated soon after.

Boris did not produce a confirmed landfall of its low-level center; operationally it was thought to have made landfall near Tonalá on June 4, but microwave imagery showed the center remained over water about 20 nautical miles offshore before dissipating over the Gulf of Tehuantepec later that day. Strong coastal and mountain gusts were recorded in Chiapas while the storm’s convection affected land.

The storm’s maximum sustained winds were 40 knots (46 mph) with a minimum central pressure of 998 mb at peak intensity on June 3; at peak Boris was a moderate tropical storm (below hurricane strength).

Rainfall was the main hazard. The highest measured 72-hour total in Mexico was 17.91 inches (454.8 mm) at Tres Picos, Chiapas. Other large totals included 15.72 inches (399.3 mm) and 13.15 inches (334.1 mm) at sites near San Pedro, Tabasco, 11.63 inches (295.5 mm) at Pijijiapan, Chiapas, and 10.24 inches (260.0 mm) at Candelaria and Palizada in Campeche. In Guatemala, totals included 9.27 inches (235.4 mm) at Mazatenango and 9.24 inches (234.7 mm) at La Reforma. Reported storm-surge or specific coastal surge measurements were not recorded in the report, though tropical-storm-force winds likely occurred along parts of the immediate Chiapas coast; a gust of 37 kt (43 mph) was observed at La Encrucijada, and higher gusts were reported at elevated mountain stations.

Boris’s rains and the precursor disturbance caused flooding and landslides in Guatemala and southeastern Mexico. Guatemala reported five deaths and seven injuries in San Pedro Necta from a landslide tied to the precursor system; about 100,000 people were affected by flooding there and 223 homes were damaged. Media and official reports indicated that flooding in Mexico did not produce widespread damage and no direct storm-related deaths were reported in Mexico during Boris’s tropical phase.

Noteworthy items: the system was well anticipated—NHC highlighted the area for possible development more than four days before genesis—and forecasts of formation and track were generally good. Post-storm analysis clarified that the low-level center remained offshore and did not make the landfall that was indicated in operational products.