Avalanche warning for region Hallingdal Sunday 10.02.2019

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half 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 • Likely • 2 - Medium • Some steep slopes N, NE, E above 0 masl • Observasjoner kun gjort i le sider

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • Unlikely • 2 - Medium • Some steep slopes N, NE, E above 0 masl • Tester gjort i le områder. Antageligvis mindre overliggende snødybde i vindutsatte områder som vil øke sannsynligheten for å løse det ut

Avalanche Problems

• Dry slab avalanche • Buried weak layer of surface hoar • 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.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow above a crust • Within half a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • above 1300 masl

Avalanche Problems

• Dry slab avalanche • A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 1 - Small • Many steep slopes W above 1100 masl

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow above a crust • Within half a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • 2 - Medium • Many steep slopes above 1400 masl

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow above a crust • Within a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 2 - Medium • Many steep slopes N, W above 1300 masl

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 1 - Small • Bryter ikke lett. Q2

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • Unlikely

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 900 masl • Nysnø fra en periode med snøfall uten vind. Utbredt i alle himmelretninger, spesielt le heng.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 1 - Small • Some steep slopes above 1100 masl • Leområder i alle himmelretninger

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within a meter • A big and identifiable crystal in the weak layer. • Difficult to trigger • Unlikely • 1 - Small • N, NE, E, SE, S, SW, W, NW • Kantkorn undrer skare kal være problem der den der dekket Av fokksnø. Det varierer fra 10 cm til 1,5 meter. Derfor vanskelig å bestemme hvor dette er et problem selv om kantkornet har stor utbredelse.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within a meter • The weak layer collapses easily and clean (easy propagation). • Difficult to trigger • Possible • 3 - Large • Some steep slopes W above 1000 masl

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes W • Sjiktovergang i fokksnøen 30 cm u overflaten, 80 cm over bakken. Kantkorn rett over bakken og under skarelag 35 cm over bakken, ca 1.5mm store krystaller. Snøen synes homogen og stabil mellom 35cm (skare) og 80 cm (Sjiktovergang av nyere dato, ennå ikke stabilisert). Snøtemp ca - 5 i overflate, - 1 ved bakken.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 900 masl

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within a meter • The overlying slab is soft. • Difficult to trigger • Possible • 3 - Large • Many steep slopes N, NE, E, SE, S, SW, W, NW above 1100 masl

Avalanche Problems

• Buried weak layer of faceted snow beneath a crust • Within half a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Gjorde blokktest. Brøt ved svakt lag under skare.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, W, NW above 0 masl • I høgden er det mulig det overliggende lag er hard fokksnø med mer spenstige egenskaper.

• Dry slab avalanche • Buried weak layer of surface hoar • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 3 - Large • Few steep slopes W above 1200 masl • Avslører av drønn ved 4-5 personer. Har ikke observert andre tegn i fjellet på at dette er et utbredt problem.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, S, SW, W, NW above 1000 masl

• Dry slab avalanche • Buried weak layer of surface hoar • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft. A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 3 - Large • Few steep slopes W above 1200 masl • Usikker på utbredelsen av rimlaget

Avalanche Problems

• Buried weak layer of new snow • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft.

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Over one meter • A big and identifiable crystal in the weak layer. • Difficult to trigger

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The collapsing weak layer is thin < 3 cm. • To skredproblem: 1)kantkornet snølag dypt i snødekke, og 2) et nedføyket nysnølag høyere i snødekke. Varierende hardhet på det øverste laget, avhengig av vindpåvirkning.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 1 - Small

• Dry slab avalanche • Buried weak layer of faceted snow above a crust • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. A big and identifiable crystal in the weak layer. • Difficult to trigger • Unlikely • 1 - Small

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, NE, E, SE, S, SW, W, NW above 900 masl • Hovedvindretningen har vært fra øst og vest men på grunn av terrengformasjoner kan man finne skredproblemet i alle himmelretninger.

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • Within a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Very difficult to trigger • Unlikely • 3 - Large • Many steep slopes N, NE, E, SE, S, SW, W, NW above 1100 masl

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 • Many steep slopes N, NE, SW, W, NW above 1000 masl

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, S, SW, W, NW above 1000 masl • I høyden mulig at flakene er hardere

• Dry slab avalanche • Buried weak layer of surface hoar • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 3 - Large • Few steep slopes W above 1200 masl • Drønn når 4 skiløpere går tett. ECT så løsner blokk ved utskjæring. Få heng, grunnet ikke observert andre faretegn som naturlig utløste skred.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of surface hoar • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft. A big and identifiable crystal in the weak layer. • Difficult to trigger • Likely • 2 - Medium • Few steep slopes above 1100 masl

Avalanche Problems

• Buried weak layer of new snow • Within a meter • The collapsing weak layer is thin < 3 cm. • Some steep slopes above 1100 masl • Nedføyket løssnø i lesider over tregrensa.

• Buried weak layer of faceted snow beneath a crust • Within a meter • A big and identifiable crystal in the weak layer. • Fant godt utviklede kantkorn/begerkrystaller under skarelag, og noe kantkorn over skaren.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, S, SW, W, NW above 1000 masl

• Dry slab avalanche • Buried weak layer of surface hoar • Within half a meter • The weak layer collapses easily and clean (easy propagation). The collapsing weak layer is thin < 3 cm. The overlying slab is soft. A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 3 - Large • Few steep slopes SW, W, NW above 1300 masl • Gruppa stod på ryggen da rimen kollapset. Veldig uklart hvor stor utbredelsen av problemet er. God oppgave for observatører i området for dei kommende dagene. Vi lagde et ECT og fikk utgliding på isolering

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The collapsing weak layer is thin < 3 cm. The overlying slab is soft. • Easy to trigger • Possible • 1 - Small • Many steep slopes N, NE, E, SE, S, SW, W, NW above 800 masl

• Dry slab avalanche • Buried weak layer of faceted snow near the ground • Within half a meter • The collapsing weak layer is thin < 3 cm. A big and identifiable crystal in the weak layer. • Difficult to trigger • Possible • 2 - Medium • Some steep slopes above 700 masl • Kantkorn har vært observert både over og under skarelag, samt ved bakken. Det mest utviklede har vært observert under skarelaget og inneholder en del begerkrystaller.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, NE, SW, W, NW between 1300 masl and 1000 masl • Nysnøflak.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • 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 above 1100 masl • Myke fokksnøflak. Litt vanskelig å få grep om situasjonen. Men dette laget virker som det mest fremtredende.

Avalanche Problems

• Dry slab avalanche • Buried weak layer of new snow • Within half a meter • The overlying slab is soft. • Easy to trigger • Possible • 2 - Medium • Some steep slopes N, NE, E, SE above 1100 masl • Mykheten på det overliggende laget/flatet varierer. Det varierer også mye i mektighet.

• Dry slab avalanche • Buried weak layer of surface hoar • Within a meter • The collapsing weak layer is thin < 3 cm. • Difficult to trigger • Possible • 2 - Medium • Some steep slopes N, NE, E, SE above 1100 masl • Problemet finnes innad i litt eldre fokksnø. Jeg antar at problemet sammenfaller i utbredelse og høydenivå med skredproblem 1. Litt usikker på dette, men vestavind har høyst sannsynlig frakta den snøen som problemet har oppstått i til østvendte leområder. Fikk utslag i lb, ct og ect på dette laget, men generelt måtte det stor belastning til for å fremprovosere brudd.

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 N, NE, E, SE, S, SW, W, NW above 1100 masl • Finner fokksnø i alle himmelretninger, ferskest i heng mot S og SØ. Mest snø i heng mot Ø og V, sidelasting også i renner og søkk mot N og S. Stort sett myke flak over alt unntatt nær kuler og rugger. Dagens stabilitetstester i Ø og V-vendt terreng viser ingen dramatisk sjiktning i fokksnøen som generelt virker bra stabil. Pålagring skjer fortsatt og det kommer mere snø.

• Dry slab avalanche • Buried weak layer of faceted snow beneath a crust • 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. • Difficult to trigger • 2 - Medium • Few steep slopes N, NE, E, SE, S, SW, W, NW above 1100 masl • Kantkornlag fins i alle hellingsretninger. Har i dag oppsøkt terreng med relativt tynt snødekke for å se etter kantkorn. Hvis en ser tilbake på vinterens historikk, oppsto skarelaget med mildværet rundt jul. Da var det lite snø og lite sammenhengende snødekke med unntak av Ø-vendte heng. Etter det har det vært jevnlige påfyll med snø og jevnt kaldt. Ut ifra det skulle en tro at kantkornlaget er begrenset til de områdene som hadde snø ved juletider, og altså ikke store sammenhengende områder med unntak av Ø-vendte heng. Tror ikke skred str 3 er særlig aktuelt av den grunn, i hvert fall ikke i heng mot N-V-S