The system was first noted on January 27, 1990, near Tuvalu, as a shallow tropical depression that had developed within the South Pacific Convergence Zone.

The cloud pattern slowly organized, and on January 31, while located east of Tuvalu, Ofa attained cyclone intensity.

[1] As a result, two shallow tropical depressions were spawned; one over the Coral Sea that went on to become Cyclone Nancy, while the other was first noted within the SPCZ over Tuvalu on January 27.

[4] Early the next day as the system started to accelerate towards the south-southeast towards the island nation of Niue, the NWOC estimated that Ofa had peaked with 1-minute sustained wind speeds of 215 km/h (130 mph), which made it equivalent to a category 4 hurricane on the SSHWS.

[6] Later that day the FMS estimated that the system had peaked as a category 4 severe tropical cyclone, with 10-minute sustained wind speeds of 185 km/h (115 mph).

[4] The system subsequently weakened very quickly and started to transition into an extratropical cyclone, as it encountered strong upper level winds and cooler waters.

[10] The system affected seven different island nations and caused gales or much stronger winds in six of those countries, which resulted in damage ranging from moderate to very severe.

[13] During January 31, after Ofa's precursor depression had remained near the edge of its area of responsibility for a few days, the Wallis and Futuna Meteorological Service decided to inform local authorities about the system and their expectations for it to develop further.

[4] After the system continued to move southwards and had become a severe tropical cyclone it triggered the declaration of a red alert as well as the Organization of the Civil Security Response plan for the whole of the territory.

[4][14][10] A gale warning was issued by the FMS for the whole of Tokelau during February 2, as Ofa started to affect the island with heavy rain, high seas and strong to gale-force winds.

[2][15][16] Around 80% of the breadfruit and coconut trees were destroyed or damaged by the winds, while an inundation of water associated with Ofa was responsible for washing away or contaminating topsoil.

[16] Cyclone Ofa affected Western Samoa between February 1–4, with heavy rain, huge waves, sea spray, storm surge and wind gusts exceeding 150 km/h (95 mph).

[nb 1][4] This created an impact on the island nation that had not been encountered in over 100 years, while the entire population was left in a state of shock.

[4] At the height of the storm the only means of communication with Western Samoa, was through a Polynesian Airlines Boeing 727 aircraft that was standing at Faleolo Airport.

[4] The Apia meteorological office was hit by high sea waves at 21:45 UTC (10:45 SST) and had to be abandoned due to rising floods before being completely destroyed a few hours later.

[22] The President subsequently declared the islands a major disaster area on December 9, which enabled Samoans to claim federal aid.

[4] Severe damage to houses, church buildings, coconut plantations, food crops and other vegetation, was reported on the islands of Tafahi and Niuatoputapu.

[4][25] Radio New Zealand subsequently broadcast Special Weather Bulletins for Niue on air, after being requested to by the FMS and the NZMS.