Originating from an area of disturbed weather near the Caroline Islands on November 9, Forrest was classified as a tropical depression three days later over the South China Sea.

Tracking generally west, the system steadily organized into a tropical storm, passing Vietnam to the south, before striking Thailand along the Malay Peninsula on November 15.

On November 20, as Forrest reached its peak intensity, fears arose across Bangladesh that a repeat of the catastrophic April 1991 cyclone would take place.

[1] Moving generally west-northwest,[2] convection associated with the system steadily organized and the Joint Typhoon Warning Center (JTWC) subsequently issued a Tropical Cyclone Formation Alert (TCFA) on November 10.

Development into a tropical depression was not anticipated until the system cleared the Philippines; however, organization was slower than forecast and a second TCFA was issued late on November 11.

The disturbance was designated Tropical Depression 30W at 12:00 UTC,[1] when it was 940 km (580 mi) east-southeast of Ho Chi Minh City, Vietnam.

Forrest made its closest approach to the nation on November 14, passing 110 km (68 mi) south of Cà Mau province.

[2] The storm's proximity to land inhibited intensification, and it attained winds of 100 km/h (62 mph) as it moved over the Gulf of Thailand on November 14.

Strengthening continued through early on November 20, at which time Forrest reached its peak intensity with winds of 230 km/h (140 mph), a Category 4-equivalent cyclone on the Saffir–Simpson hurricane scale.

[1] The IMD assessed three-minute sustained winds to have been 185 km/h (115 mph), making it a modern-day "extremely severe cyclonic storm", and its barometric pressure was estimated at 952 mbar (hPa; 28.11 inHg).

[2] The IMD estimated Forrest to have been far weaker as it moved ashore, reporting peak three-minute winds to be 85 km/h (53 mph) at that time.

It became the first North Indian Ocean cyclone to be observed by scatterometer instruments, providing the data necessary to calibrate the device for minimizing directional ambiguity of its measurements.

[8][9] After descending below a safe altitude on approach to Nha Trang, the Yakovlev Yak-40 aircraft deviated 6 km (3.7 mi) from the runway and impacted trees at the top of a ridge before crashing 350 m (1,150 ft) away.

Amid forecasts that Forrest's intensity at landfall would be greater than that of the April 1991 cyclone, officials and volunteers scrambled to warn residents in its path of the impending danger.

[21] The cyclone ultimately spared the country a direct hit, turning due east, weakening, and striking Myanmar on November 21.

[20] Meteorologists regarded the storm's change of course and weakening as a "miracle", as large cyclones have historically caused tremendous loss of life and damage in Bangladesh.

[22] Off St. Martin's Island, the southernmost area in Bangladesh inhabited by 4,500 fishermen, high winds snapped radio lines to the mainland.

[21] On nearby Shah Farid Island, 200 thatched homes were damaged; all 500 families had previously evacuated and were left unharmed.