{"id":98824,"date":"2025-12-31T14:54:39","date_gmt":"2025-12-31T14:54:39","guid":{"rendered":"https:\/\/www.s1trail.com\/?p=98824"},"modified":"2026-06-09T06:06:06","modified_gmt":"2026-06-09T06:06:06","slug":"c26","status":"publish","type":"post","link":"https:\/\/www.s1trail.com\/en\/c26\/","title":{"rendered":"Archive 2026 \u2014 Operation Clear Bora: technical guide to frost and thermal contrasts"},"content":{"rendered":"
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source: https:\/\/www.meteo.fvg.it\/<\/a><\/figcaption><\/figure>\n\n\n\n

The latest analysis of intermediate model calculations ECMWF<\/strong> e GFS<\/strong>, crossed with high-resolution projections ICON<\/strong>, confirm that the initially predicted disturbance has been pushed back southwards. This scenario opens the door to the so-called \u201cBora Chiara\u201d<\/strong>A meteorological event characterised by clear skies<\/strong>, exceptional visibility<\/strong> and an influx of arctic-continental air<\/strong> from the Balkans. It will not be a race against the mud, but an endurance challenge against the frost<\/strong> and the dry wind<\/strong>with temperature excursions<\/strong> which will require meticulous energy and clothing management.<\/p>\n\n\n\n

The territory of the Karst<\/strong> will present two opposite worlds in the space of a few kilometres. At sinkholes<\/strong> and in the inland basins we will see a very strong thermal inversion<\/strong>night frosty air will be trapped at the bottom, bringing actual temperatures down to -8\u00b0C<\/strong> and making the ground hard as concrete<\/strong>. On the contrary, along coastal stretches and in cities, solar radiation may create some \u201coasis\u201d<\/strong> sheltered from the wind with perceived temperatures up to +10\u00b0C<\/strong>. This temperature change of almost twenty degrees<\/strong> is the number one danger for the emergence of cramps<\/strong> and for the management of body heat<\/strong>. From a physiological point of view, remember that the Dry Bora<\/strong> accelerates the invisible dehydration<\/strong>sweat evaporates instantly and the feeling of thirst disappears, but the body continues to lose fluid and burn glycogen<\/strong> much faster to maintain the internal temperature. It is vital drinking<\/strong> e feeding regularly<\/strong> even in the absence of stimuli.<\/p>\n\n\n\n

For those who will face the overnight departures<\/strong>, the frost will also be a challenge for technology: we recommend keeping the mobile phones<\/strong> and the replacement batteries<\/strong> in contact with the body, as extreme cold can halve the charge<\/strong> of lithium batteries in less than an hour. For those leaving in the morning, the priority will be the dynamic stratification<\/strong>. The most common mistake is dressing too much for the perceived cold at the start line; it is better to start slightly \u201cunderclothes\u201d<\/strong> knowing that the body will warm up in a few minutes, while maintaining the gloves<\/strong> and the shell<\/strong> at hand for sudden entry into the shaded areas<\/strong> of the sinkholes where the night frost will still be active.<\/p>\n\n\n\n

Based on these technical considerations, we ask you to pay close attention to the following material and safety advice:<\/p>\n\n\n\n