 On October 27 , an area of convection with a broad circulation persisted southeast of Guam , and slowly consolidated due to moderate wind shear and westerly outflow . That day , the Japan Meteorological Agency ( JMA ) classified the system as a tropical depression about 380 km ( 235 mi ) to the southeast of Hagåtña , Guam . At 2100 UTC on October 28 , the Philippine Atmospheric , Geophysical and Astronomical Services Administration ( PAGASA ) began issuing advisories on the depression , giving it the local name Vinta . The next day , the JMA upgraded the depression to Tropical Storm Krosa ( 1329 ) , and the Joint Typhoon Warning Center ( JTWC ) also classified it as Tropical Depression 29W . By that time , the storm was moving steadily westward due to the subtropical ridge to the north . With the warm waters of the Philippine Sea , lessening wind shear , and improving outflow , Krosa gradually strengthened , and the JTWC also upgraded Krosa to tropical storm status on October 30 after an eye feature developed . 
 On October 27 , an area of convection with a broad circulation persisted southeast of Guam , and slowly consolidated due to moderate wind shear and westerly outflow . That day , the Japan Meteorological Agency ( JMA )<a href='been_done' title='1'><mark></mark></a> classified the system as a tropical depression about 380 km ( 235 mi ) to the southeast of Hagåtña , Guam . At 2100 UTC on October 28 , the Philippine Atmospheric , Geophysical and Astronomical Services Administration ( PAGASA ) began issuing advisories on the depression , giving it the local name Vinta . The next day , the JMA<a href='been_done' title='2'><mark></mark></a> upgraded the depression to Tropical Storm Krosa ( 1329 ) , and the Joint Typhoon Warning Center ( JTWC ) also<a href='been_done' title='3'><mark></mark></a> classified it as Tropical Depression 29W . By that time , the storm was moving steadily westward due to the subtropical ridge to the north . With the warm waters of the Philippine Sea , lessening wind shear , and improving outflow , Krosa gradually strengthened , and the JTWC also upgraded Krosa to tropical storm status on October 30 after an eye feature developed . 
On October 27 , an area of convection with a broad circulation persisted southeast of Guam , and slowly consolidated due to moderate wind shear and westerly outflow . That day , the Japan Meteorological Agency ( JMA ) been classified the system as a tropical depression about 380 km ( 235 mi ) to da southeast of Hagåtña , Guam . At 2100 UTC on October 28 , the Philippine Atmospheric , Geophysical and Astronomical Services Administration ( PAGASA ) began issuing advisories on tdadepression , giving it thdaocal name Vinta . The nxt day , the JMA done upgraded thedapression to Tropical Storm Krosa ( 1329 ) , and the Joint Typhoon Warning Center ( JTWC ) also been classified it as Tropical Depression 29W . By dat time , the storm was moving steadily westward due to the subtropical ridge to the north . With the dam waters of the Philippine Sea , lessening wind shear , and improving outflow , Krosa gradually strengthened , and the JTWC also upgraded Krosa to tropical storm status on October 30 after an eye feature developed .