Punctually on Christmas Eve temperatures dropped to wintery levels and snowfall arrived down to the valley floor in East Tirol. About 10-20cm was registered in the mountains, nearly nothing in North Tirol. As a result of stiff easterly winds, snowdrifts accumulated from place to place, particularly where there was fresh fallen snow. Most were small but in unfavorable terrain sufficient to force a fall with possible injuries. Outside of secured ski-runs, skiing conditions remain downright miserable.
Current situation
White Christmas in East Tirol
On Christmas Eve there was snowfall in East Tirol extending down into the Lienz basin. It was made possible by the interplay of cold air masses from the east and moist air masses from the Mediterranean. It was hardly heavy snowfall, but in view of the current snow situation even a little bit is welcome.
In southern East Tirol 10-20cm of fresh snow was registered, further north, less. The snowfall was accompanied by frequently strong easterly winds.
Effects on avalanche danger
In the mountains of East Tirol the loosely-packed fresh snow was transported by winds, generated fresh snowdrift accumulations. On shady slopes at high altitudes, these were deposited on top of an expansively metamorphosed, shallow old snowpack, on sunny slopes it often fell on bare ground. The currently relevant danger zones are thus concentrated on precisely these north-facing slopes, where in very steep terrain small snowdrifts can be triggered from place to place. The azure skies are cloudless and visibility is superb, so these are easily recognized and can be avoided. These small-sized drifted masses are especially perilous in terrain where falls are risky.
In North Tirol, on the other hand, the situation has changed little since last week, avalanche danger remains low. Due to gusty, often strong-velocity southeasterly winds, isolated small-sized but trigger-sensitive snowdrift accumulations were generated behind protruberances in the landscape on shady slopes above 2600m. Slab avalanches in the old snow are unlikely to trigger at this time, the slab metamorphosed expansively during the period of fine weather so fractures can hardly be expected to propagate.
Coming developments
The lack of snow sets clear-cut limits to any plans in outlying terrain, and even the fresh snowfall is more enjoyable to look at than to ski on. Until at least the end of the year this situation is not expected to change. Over the weekend we will have picture-perfect weather amid mild temperatures.
As the new year approaches, temperatures will drop feelably and a possible weather shift is conceivable in the early days of the new year, including snowfall. Long-term weather forecasts are untrustworthy, but we can hope.
The entire team of the Avalanche Warning Service of Tirol wishes everyone Merry Christmas and a relaxing holiday season.