On April 17, 1998, the Fiji Meteorological Service (FMS) started to monitor the development of a tropical disturbance east of the Northern Cook Islands.

[2] Over the next couple of days, the system slowly moved northwards, gradually organizing, with gale-force winds developing in its southern quadrant on April 20.

[4][5] Later that day the Naval Pacific Meteorology and Oceanography Center (NPMOC) started to issue warnings on Alan and accidentally assigned it the designation 32P as opposed to 36P, estimating peak 1-minute sustained wind speeds of 85 km/h (50 mph).

[1][2][7] Over the next day, as a mid-level trough of low pressure shearing Alan moved faster than expected, the depression became better organized and developed favorable upper-level outflow.

[2][8] As a result, the NPMOC initiated advisories on the system again on April 24, and later that day, the FMS reported that Alan re-intensified into a Category 1 tropical cyclone.

[2][9] Cyclone Alan produced high winds and torrential rain over French Polynesia between April 24 and 25, causing several landslides on the Society Islands,[2][10][11] resulting in the collapse of two bridges and obstruction of roads by fallen trees.

[12] On Huahine, the extent of the damage, along with a sharp dip on the Uturoa barograph trace, suggested that a tornado may have been spawned in one of Alan's convective bands.

[1][4][15] During December 1998, the European Community Humanitarian Office responded to a government appeal, providing €105,000 for tents, medical aid, food and clothing.