初夏の雪と濃霧。低温と視界不良に警戒

Currently, Mount Asahidake summit is experiencing snowfall, with a temperature of -0.7°C and a wind chill of -4.6°C. Humidity is high at 99%, and visibility is less than 1km due to dense fog. At the base, it is heavy drizzle at 2.7°C. A mere 500m elevation difference separates snow and rain, presenting winter-like conditions at the summit. Drizzle is expected to continue throughout the day, with temperatures ranging from 0°C to 2.7°C, but wind will keep the perceived temperature below freezing all day.

The trails are a mix of 19cm of residual snow and mud from melting snow. Especially on the route from Asahidake Ropeway Sugatami Station towards the summit, deep snow remains in shaded areas and snowdrifts, requiring caution against post-holing. Wet rocks and mud make for slippery conditions, and light crampons or chain spikes may be useful in some sections. Waterproof and breathable outerwear is essential. A quick-drying base layer, a fleece or thin down mid-layer, gloves, and a knit hat are also necessary. The high humidity and risk of getting wet significantly increase the danger of hypothermia.

The dense fog with visibility under 1km means conditions near whiteout once you step outside the Asahidake Ropeway Sugatami Station. Around the Fumarole Group Jigokudani, it is easy to lose track of trail markers, and there is an extremely high risk of approaching hot steam or gas from fumaroles, as well as falling. Reckless actions must be avoided. Under today's conditions, even experienced climbers need extreme caution, and ill-advised entry should be avoided. While the weather is forecast to improve in the evening with clear skies overnight, temperatures will drop to -1.7°C. Therefore, any activity should be limited to daylight hours, waiting for visibility to improve, or postponing the plan altogether.