The Joint Typhoon Warning Center (JTWC) assessed Cecil to have been slightly stronger with one-minute sustained winds of 140 km/h (87 mph).

In the wake of the flooding, some international aid was sent to Vietnam, though most relief work was conducted by the nation's government, local agencies, and the Red Cross.

On May 20, following Typhoon Brenda's passage through the South China Sea, a monsoon trough extending from the area into the Bay of Bengal received enhanced low-level southwesterly flow.

An environment of weak wind shear in the wake of the typhoon allowed a new area of low pressure to form within the southwesterly flow on May 21.

[3][nb 2] Later that day, convection wrapped entirely around the center of circulation; this structural improvement, combined with nearby surface observations, prompted the JTWC to designate the system as Tropical Storm Cecil.

[5] However, the JMA reported Cecil to have been slightly weaker, classifying it as a severe tropical storm with ten-minute sustained winds of 110 km/h (68 mph).

[2] In addition to the considerable losses that took place in Vietnam, Cecil also produced heavy rains in Laos and northeastern Thailand, resulting in flooding and crop damage.

[8] A total of ₫52 million ($124,000) worth of funds and relief supplies, including 1,600 m (5,200 ft) of fabric, and two tons of clothing, was sent to Quang Nam province.