Snow is no doubt one of the more interesting features in the Himalayan terrain. Where glaciers represent permanent ice, snow is temporary, falls during winter and retreats during summer. The snowline (altitude where snow starts) is very dynamic. It changes as per the seasons: fresh winter snow fall usually sets in around September and summer season (start of snow melt) starts around April.
The snowline also moves up and down during the winter itself – fresh snowfall might lower the snowline by 500 meters followed by 2 weeks of sun where the snowline retreats again 300 meters up. As usual, snow melt is more on the East / South facing slopes while the North / West facing slopes will retain fresh snow longer due to less solar exposure. Due to the dynamic nature of snow it can obviously not be marked on maps and we should follow the weather forecast to get an idea of lowering (fresh snowfall) or receding (sunny weather) of the snowline.
The snowline is very dynamic but important to plan your journey. Passes are usually “open” (free of snow) in certain months and closed during the rest of the season. 3000m+ high passes might be open May-Nov, 4000m+ passes (e.g. Dhauladar) in June-Sept, 5000m+ passes (e.g. Pir Panjal) in July-Aug. Survey of India maps usually mention the months during which marked passes are open.
Hiking in snow
Due to the dynamic nature of snow a winter exploration journey is usually planned dynamically. During winter 20/21 I crossed 110 passes during Nov-Feb over 2000km across Uttarakhand in the 2500-4000m altitude range following the snowline as moves up or down. As mentioned earlier, snow changes the landscape completely – it covers the terrain with a white blanket blanking out any trails or paths. Navigation becomes much more challenging as trails get partly / fully covered by snow.
Winter treks in commercial groups are easy as someone periodically clears the trail for you. Alpine style exploration treks in winter are a different game – you are the one who has to find and open the way through deep snow. My general rule of thumb is to keep the snow below the knee level as otherwise the effort becomes too much and pace too slow. As a lightweight fast hiker I use my regular trail shoes with water proof socks to keep my feet dry instead of (heavier) gaiters and snow crampons.
Always remember that you ll encounter more snow on North / West facing slopes compared to East / South facing slopes while planning a traverse. Sometimes cases trails might eventually fade out below the snow as you get closer to the pass / higher altitude / more snow. In that case you ll have to switch over to navigation using contours while holding your geo-reference map / GPS recording as a reference until you find your trail once you descend to lower altitude / less snow.
Steep snow
A steep snow covered slope can sometimes be easier to traverse compared to a barren slope of slippery rock or loose scree. Soft snow provides a better foot hold. In the first image below, a shepherd has traversed a steep snow covered gully by making a path through the snow. The same gully without snow might be much more difficult to cross.
Hiking uphill through deep snow on a steeper slope can be really exhausting (image 2 below). A pair of hiking poles can significantly increase stability and make it easier to push yourself up. On stable underground (meadows, rugged rocks) it might be easier to hike up / down on the South / East facing slopes / ridges where the snow is melted. This can be significantly faster compared to sinking knee-deep in snow on the North / West facing slopes.
Frozen snow
Things become more challenging in frozen / hard snow. Early mornings after a freezing night, the winter snow might be rock hard making it impossible to make steps with your shoes. While during late afternoon it might be soft and much easier to step across a steep snow covered gully. While traversing steep frozen snow sections (or steep glaciers) you ll need an ice axe to cut steps into the snow in order to traverse the same and avoid slipping down in the valley below.
Winter snow usually remains much longer in gullies where they are protected from the direct sun. To cross over many steep passes the trail might usually contour towards the pass from the left or right valley slope. While contouring you might encounter several snow covered (steep) gullies and you will have to plan accordingly. Either carry an ice axe or weight till later in the afternoon till you can make steps in the snow with your shoes.
Snow bridges
Another interesting phenomena are snow bridges. A snow bridge is basically an arc formed by snow across a stream, crevasse, crack in rock or other opening in the terrain. Snow bridges (if strong enough) can be very useful to cross over wild streams as you switch sides of the valley (while hiking on less steep slope). Even if the winter snow melts completely on both sides of the valley you sometimes still find large snow bridges covering the stream as the ice cold meltwater prevents the snow from melting on top.
Tens of feet of compacted winter snow can form meters of thick ice above the streams acting as a natural bridge. As the summer slowly melts the snow this massive weight of frozen snow can break under its own weight and form crevasses (see image 2 below). Snow bridges have been useful in my own journeys to cross over wild streams which would have been impossible traverse otherwise.
Assignment
Acknowledge your understanding of the diverse nature of snow while hiking in the mountains.
