Originating from a near-equatorial trough on October 26, the precursor depression to Keith slowly organized into a tropical storm.

After two days of gradual strengthening, the storm underwent a period of rapid intensification on October 30 as winds increased to 195 km/h (121 mph).

After fluctuating in strength over the following few days, a steady weakening trend established itself by November 5 as the typhoon accelerated towards the northeast.

Tracking west-northwestward in response to a subtropical ridge, the storm slowly intensified at roughly half the rate initially forecast.

However, on October 30, the storm suddenly underwent a period of rapid intensification, with sustained winds increasing from 100 to 195 km/h (62 to 121 mph) in a 24-hour span.

[2] Maintaining super typhoon status, Keith moved through the Northern Mariana Islands between 0600–1200 UTC on November 2 with winds of 260 km/h (160 mph).

The center of the typhoon moved between the islands of Rota and Tinian; however, it was discovered that the storm had a very compact field of intense hurricane-force winds, estimated to be 55 km (34 mi) across.

After moving through the islands, Keith briefly weakened below super typhoon status on November 3 as the eye became partially obscured due to an eyewall replacement cyclone.

Once the storm completed its turn, Keith accelerated and steadily weakened as it entered the westerly flow north of the ridge previously steering it westward.

Women who were more than seven months pregnant were also urged to check into hospitals, as doctors warned that changes in pressure could trigger labor.