濃霧のロックガーデン。道迷いに厳重警戒

As of 7:30 AM, Tomuraushi summit is mostly clear but visibility is less than 1km, indicating a dense fog. This highlights the specific risk of getting lost in fog, which is characteristic of Tomuraushi mountain. Navigation is particularly challenging in the Rocky Garden area where large boulders can obscure the route. The summit temperature is 7.5°C, feeling like 5.6°C, a 5.4°C difference from the base. This is comparable to conditions on 3000m peaks in Honshu.

Temperatures are expected to rise during the day, reaching 9.3°C by 9 AM and 11°C by noon. Winds will remain relatively mild, with gusts up to 7.1m/s, posing a low risk of strong winds or thunderstorms. Ground conditions are dry to partially wet due to no precipitation, with exposed rocky terrain. Considering the 5.6°C apparent temperature, a quick-drying base layer, a fleece mid-layer, and a waterproof and windproof shell are essential. Carry rain gear, warm clothing, gloves, and a hat. Due to poor visibility, a map, compass, and GPS are mandatory. Crampons or microspikes are not needed.

A light drizzle of 0.1mm is forecast around 6 PM. While the precipitation is minimal, it could further reduce visibility and make the ground wet. Tomuraushi is a long course, making day trips difficult, and rapid weather changes like the 2009 accident are a real threat. Start early and plan with ample time to complete your descent before dark. Poor visibility leading to route disorientation is identified as the primary risk today.