Tuesday, 21 January 2020

Caution: fresh snowdrift accumulations very easily triggered

In wind-impacted regions a serious snowdrift problem threatens winter sports enthusiasts. Freshly generated drifted masses are bonding (for a brief spell) extremely poorly with the frequently very loosely-packed (and cold) new fallen snow from 18-19 January 2020. (Inside the fresh snow there is also graupel that could form an additional weak layer, otherwise relatively insignificant).

Fresh, naturally triggered snowdrift mass. Tuxerjoch (photo: 21.01.2020)

The 3 ingredients of a snowdrift problem, i.e. for Danger Pattern 6 (loose snow and wind):

Fresh snow...

...which is loose and also cold... (visible in the photo: the glittering fresh-fallen snow crystals). Start of slight wind influence (photo: 20.01.2020)

Overview of the low temperatures following the snowfall

...along with wind impact. Current winds are southerly.

Snow plumes on Hintertux Glacier showcase the snow transport. (photo: 20.01.2020)

Weather developments of recent days at a wind-impacted station in Stubai Valley: fresh snow, temporarily low temperatures and wind impact beneath cloudless skies.

The good part about this is that with a certain amount of experience, the snowdrift masses can be easily recognized. In addition, the snowdrift problem is not a threat throughout the land, but only in regions along the Main Alpine Ridge and in the classic foehn lanes. In wind-protected places skiers and freeriders can still enjoy great powder.

On the other hand, fresh snowdrift masses should under all circumstances be circumvented in steep terrain.