トムラウシ残雪は緩む。午後は気温低下に注意

Tomuraushi summit area is mostly clear with a temperature of 2.7℃, feeling like -0.9℃. Temperatures will rise to 5.8℃ during the day, causing the 159cm deep snowpack to soften. Be cautious of post-holing and slippery surfaces. The current temperature difference between the summit and the base is -10.1℃, indicating winter conditions persist at higher elevations despite clear skies at the base.

Around the Rock Garden and the Kitamuma and Minaminuma alpine wetlands, mixed conditions of snow and exposed rock will become more prevalent. Caution is advised for hidden rocks, crevices under the snow, and icy patches. Remember the lessons from the 2009 accident and be prepared for sudden weather changes.

As indicated by the automated risk assessment, a rapid temperature drop of 6℃ is expected during the forecast period. Temperatures will fall rapidly after 3 PM, reaching below freezing overnight. The perceived temperature during activity will further decrease from the current -0.9℃ into the night. For layering, use a wicking base layer, a fleece or light down mid-layer, and a windproof/waterproof shell as outer protection. Carry an extra heavy down jacket for breaks and bivouacs. Given the long and challenging nature of the course, be prepared to turn back early.

With a significant snowpack of 159cm, soft snow during the day will freeze overnight, making light crampons or microspikes essential. Visibility is currently excellent at over 20km, but Tomuraushi Mountain is prone to high risks of getting lost in dense fog. Always use GPS in conjunction with a map to confirm your location.