Avalanche warning for region Hallingdal Wednesday 11.12.2019

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 1000 masl • 10 cm lag fra bakken med kantkorn ca 2 - 2,5 mm. Vanskelig å løse ut

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within half a meter • The collapsing weak layer is thin < 3 cm. • Very difficult to trigger • 2 - Medium • N, NE, E, W, NW above 1000 masl • Meget tynt skarelag. Pakket fokksnø over og under.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 1100 masl • The faceting was widespread, but the overlying load was variable due to spatial variability in the terrain and loading of the storm slab.

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 1000 masl • Vind fra SØ sist natt med samtidig snøfall. Pålagring vil trolig ha skjedd i le retning av vinden.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within half a meter • A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Few steep slopes N, NE, E, W, NW above 1200 masl • Hard fokksnø nokon plassar, men mjukare innimellom. Me kan ikkje seie om skredproblemet går heilt til topps. Me gjekk hardt ut for å finne skredproblematikk i fokksnøen, men dette fant me ikkje. Over tregrensa har det vore mykje vind inatt og snøen er blåst inn i lesider og i forsenkningar i terrenget.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 1000 masl • Nødvendig med vindtransportert snø i leområder for å løse ut flakskred. Det er fokksnø over tregrensa og i aspektet V til N til Ø. Det er også registrert svake lag i fokksnø og svakt lag ved skare, det er lett å løse ut, men tilstede i få heng.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 1000 masl • Kantkornlag er utbredt, men ikke veldig potent og krever stor tilleggsbelastning for å trigges.

Avalanche Problems

• Dry slab avalanche • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Few steep slopes N, NW

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • The overlying slab is soft. A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Many steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl • Kant korn ved bakken, kantkorn er best utviklet hvor snødekke er tynt.

• Poor bonding between layers in wind deposited snow • Easy to trigger • 1 - Small • Some steep slopes N, NE, E above 1000 masl • Mye vind transport i høyden. Kan være dårlig binding i fokk snøen i noen heng

• Buried weak layer of faceted snow beneath a crust • Easy to trigger • 2 - Medium • Many steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl • Oppbyggende utvikling ved skare lag i snødekket. Bør følge med dette laget

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within half a meter • A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Few steep slopes N, NE, E, SE, S, SW, W, NW above 1200 masl • Hard fokksnø noen plasser, noe mykt innimellom. Vi kan ikke si noe om snøproblemet går helt til topps. Vi lette etter skredproblem i fokksnøen, dette fant vi ikke. Vi hadde en del drønn i snøen, der vi påvirket kantkornlaget nederst i snødekket. Der snødekket er tynt påvirket vi snødekket lett.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 800 masl • Veldig usikker på hvor langt ned dette problemet går, vi har ikke vært lavere enn 1100moh, og skredproblemet var tilstede her. Vi har kun vært i nordlig sektor, kan ikke si noe om utbredelsen utover dette, men forventer at problemet er tilstede alle steder der det ligger et flak.

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Difficult to trigger • 2 - Medium • Few steep slopes N, NE, E, W, NW not between 1300 masl and 800 masl • Dette skredproblemet er mindre viktig. Vi fant skarelaget med kantkorn under opp til ca. 1300 moh. Det virker som skarelaget ikke eksisterer høyere enn dette, og dermed er ikke problemet lenger tilstede. Dette laget er mindre viktig.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Some steep slopes N, NE, E, W, NW above 800 masl • Vi har vært i nordlig sektor, men antar at problemet er til stede i alle himmelretninger. Ferskeste flak ligger i nordlig sektor Vi gikk aktivt ut for å finne fokksnø problemet. Dette har vi ikke observert eller funnet

Avalanche Problems

• Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Some steep slopes N above 800 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • Difficult to trigger • 2 - Medium • Few steep slopes N, NE, E, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, W, NW above 800 masl

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • The overlying slab is soft. • Difficult to trigger • 2 - Medium • Many steep slopes N, NE, E, SE, S, SW, W, NW above 800 masl • Brudd i dette laget er rufsete og laget er tykt, samt at det ligger på bakken der steiner og vegetasjon vil hindres stor bruddforplantning.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. A big and identifiable crystal in the weak layer. • Easy to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW • Svake laget finnes i alle himmelretninger. Veldig stor variasjon i snøen over det svake laget. Mykere lag under tregrens, over tregrensa har laget bundet seg litt bedre. Variert tykkelse på snølaget etter hvor vinden har lagt fra seg snøen

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Difficult to trigger • 1 - Small • Few steep slopes N, W, NW

Avalanche Problems

• Poor bonding between layers in wind deposited snow • Within half a meter • Some steep slopes N, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Difficult to trigger • 1 - Small • above 1000 masl • Ubunden løs snø i skog, fokksnø over tregrense, ca 1000 moh. Observert i SørVestvendt heng, ikke vært tilstede i andre eksposisjoner.

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 1 - Small • above 1100 masl

Avalanche Problems

• Buried weak layer of new snow • Within half a meter

Avalanche Problems

• Dry slab avalanche • Difficult to trigger • 1 - Small • Few steep slopes NW • Nedbør som snø frå søraust

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes above 800 masl

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Over one meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes • Vi fant kantkorn langs bakken både over og under skare. En annen gruppe hørte et drønn i samme området, men vi klarte ikke å fremprovosere noe initiering eller propagering. Det lå mer enn 1 meter dypt der vi gravde, men gjennomsnittlig dybde er nok noe mindre. Snødybden varierer mye i terrenget som følge av vindtransportert snø.

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes SE, S, SW, W above 1000 masl • Utbredelsen av skredproblemet er relativt stor da vinden har dreid en del siste døgn

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes SE, S, SW, W above 1000 masl • Utbredelsen av skredproblemet er relativt stor da vinden har dreid en del siste døgn

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes SE, S, SW, W above 1000 masl • Utbredelsen av skredproblemet er relativt stor da vinden har dreid en del siste døgn

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes SE, S, SW, W above 1000 masl • Utbredelsen av skredproblemet er relativt stor da vinden har dreid en del siste døgn

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes SE, S, SW, W above 1000 masl • Utbredelsen av skredproblemet er relativt stor da vinden har dreid en del siste døgn

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Poor bonding between layers in wind deposited snow • Within half a meter • The overlying slab is soft. • Easy to trigger • 2 - Medium • Some steep slopes SE, S, SW, W above 1000 masl • Utbredelsen av skredproblemet er relativt stor da vinden har dreid en del siste døgn

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 1000 masl