Today, radar shows that a solid line of showers will move across Fuji Speedway, associated with a cold front. As the front moves southeast, it will stall near the southern coast of Japan, just south of the track. Warm, moist air riding up and over the front will keep periods of rain going through Saturday and Sunday. The flow of moisture over the front appears to be weaker than it did a few days ago, so I have lowered the forecast rainfall amounts on Saturday, and dropped the Impact back to Moderate. This means that all planned on-track activity should be able to be completed, but probably not without some delays or at least the use of rain tires.
The pattern doesn't change much for Sunday, and periods of rain will continue to affect the racing action. Rainfall amounts look higher on Sunday than Saturday, with up to a half inch (13 mm) expected through the day. I think it will be a steady light to moderate rain, rather than a heavy rain that will cause the race to be stopped. Thus, I have the Impact as Moderate. With the surface front located to the south, temperatures will be cool all weekend.