Dvorak technique
Twelve hours later, the JTWC upgraded the tropical depression to a tropical storm based on Dvorak technique satellite intensity estimates and the storm exhibiting tightly-curved convective bands. An upper-level low helped to reduce wind shear that had been affecting the storm. The JTWC also warned of the possibility of rapid intensification. The JMA upgraded the depression to a tropical storm later that day and named it Sepat, a name contributed by Malaysia referring to a freshwater fish species.