late on september 4, an area of low pressure developed to the southeast of okinawa, japan. over the next two days, the system drifted north and developed a well defined llcc with organized convective banding, prompting the jma to upgrade the low pressure area to a tropical depression. on september 7, convection consolidated the low-level circulation center very well with tightly curved banding wrapped into it. also, high sea-surface temperatures and very low wind shear caused the system to undergo rapid deepening, prior to which, the jma upgraded the system to a tropical storm and named it "kulap". however, the system stopped strengthening soon after as the llcc became partially exposed and the convection was displaced to the south. kulap remained small in size and dry air entering from the western periphery kept it from strengthening further. wind shear increased, pushing convection about south of the llcc. also, kulap was beneath a tropical upper tropospheric trough (tutt cell) that caused subsidence. a mid-level subtropical steering ridge cuased kulap to track in a northwestward direction. on september 8, kulap moved into the east-northeast periphery of the philippine area of responsibility (par) prompting the pagasa to start issuing advisories on the system, naming it "nonoy". however, kulap quickly accelerated north and exited the par on the same evening, prompting the pagasa to issued their final advisory on the system. after increasing wind shear caused further weakening, the jtwc downgraded kulap to a tropical depression late on september 8. early on september 10, the jma too downgraded kulap to a tropical depression, and continued to track kulap's remnants as a tropical depression until it finally dissipated early on september 11.