This lenticular cloud seems harmless, but it is not. These cloud caps are well known in the Alps (so called "barrages de foehn" by alpinists) and are very dangerous. Inside, it is a white hell with strong south winds, often far under 0°C and snow storm. The cooling effect at high altitude is rapidly concerning. Many have died so in the Alps. This meteo situation occurs during the transition from a northstream (lower cold air sheet) and a southstream above. But at these altitudes cold and warm are not at a human scale. For example in this case the forthcoming southstream made devasting & deadly inondations in Spain. The meteo charts gave clouds temperature at a high altitude down to minus 70° C, giving a disastrous condensation of the already wet and warm mediterranean air ! During such a southstream at the Klein Matterhorn (Switzerland, around 3850 m) a wind speed of 275 km/h was once recorded during the nineties.