Tropical Storm Bavi, known in the Philippines as Tropical Storm Betty, influenced the trade winds over the Pacific Ocean and was partially responsible for one of the strongest trade wind reversals ever observed. The system was first noted as a tropical disturbance during March 8, 2015, while it was located to the southeast of Kwajalein Atoll in the Marshall Islands. Over the next couple of days the system moved north-westwards through the Marshall Islands, before it was classified as a tropical depression during March 10. The system subsequently moved north-westwards and continued to develop further, before it was classified as the third tropical storm of the 2015 Pacific typhoon season and named Bavi by the Japan Meteorological Agency (JMA) during March 11. After continuing its north-westwards movement, the system peaked as a tropical storm during March 14, before it started to weaken as it approached the Mariana Islands. The system subsequently passed over Guam during the next day, before continuing its west-northwestwards movement as it gradually weakened over the next few days. The system entered the Philippine area of responsibility, where it was named Betty by PAGASA during March 17 as the system weakened into a tropical depression. The system was subsequently last noted during March 21, as it dissipated over the Philippines.