Originating from a monsoon trough, Typhoon Thad was first classified on August 15, 1981 and was upgraded into a tropical storm the next day.

On August 22, Thad accelerated northward, striking eastern Japan the next day just before weakening to a tropical storm.

Typhoon Thad originated from an active monsoon trough several hundred miles east of the Philippines in mid-August 1981.

[2][nb 1] Based on data from Hurricane Hunters, a Tropical Cyclone Formation Alert was issued by the Joint Typhoon Warning Center (JTWC) at 1800 UTC on August 15.

By 0000 UTC on August 18, the JTWC upgraded Thad to typhoon status as the cyclone developed a ragged eye.

During the evening of August 18, the agency estimated that Thad reached its peak intensity of 80 mph (130 km/h) and a minimum barometric pressure of 955 mbar (28.2 inHg).

The next day, forecasts from the JTWC indicated that the typhoon was expected to re-curve and accelerate due to a trough located south of Japan.

At 0000 UTC on August 23, the JTWC downgraded Thad into a tropical storm while moving onshore in central Japan.

[2] By this time, cooler air had taken toll on the storm,[1] and that afternoon, data from both agencies indicated that Thad finished its transition into an extratropical cyclone.

[8] Furthermore, the storm also blocked roads in 850 spots,[7] destroyed 449 others, collapsed 80 bridges,[9] broke dikes at 173 places, and generated 499 landslides.

In Akita, a fishing boat with nine people aboard was capsized by strong winds; all nine were rendered as missing by police.

[6] In the Ibaraki Province, just north of Tokyo, officials ordered the evacuation of 5,000 dwellings in the city of Ryugasaki,[12] 2,500 of which were flooded.