Avalanche forecast for Heiane Tuesday 2019-03-12

3
Considerable
Published:

The snowpack is very unstable. Avoid areas with wind-deposited snow. It is also possible to trigger avalanches in a persistant weak layer in old snow found in bowls and gullies.

New snow (slab avalanches)

Buried weak layer of new snow

Avoid terrain traps and steep slopes until the new snow has stabilized. The avalanche problem is generally widely distributed on any steep slope with deep new snow. Look for cohesive new snow that breaks apart or is poorly bonded to the old snow. Cracks around your skis are a typical dangersign.
2 - Medium
Low additional load
Widespread steep slopes
Possible

Persistent weak layer (slab avalanches)

Buried weak layer of faceted snow above a crust

Avoid skiing in avalanche terrain (steep terrain more than 30 degrees and in runout zones). NB, remote triggering is likely. Make very conservative route choices, especially in unknown terrain, after snowfall and if temperatures rise. Identifying areas where the weak layer is present might be difficult and requires experience. Danger signs are whoumpf-sounds, cracking and recent avalanches. However, absence of signs does not mean it is safe.
2 - Medium
Low additional load
Specific steep slopes
Possible

What are avalanche problems?

Observations the last 3 days (map placed)

0 mm precipitation.
Breeze from northwest., change to breeze from the southeast during the evening.
-14 °C to -4 °C at 1100 m a.s.l.
Plus degrees up to 400 m a.s.l. during the afternoon.
Partly cloudy.

For updated info, please visit yr.no
20 mm precipitation, up to 30 mm in the most exposed areas.
Fresh breeze from southeast., change to gale from the southeast during renoon.
-8 °C to -2 °C at 1100 m a.s.l.
Plus degrees up to 400 m a.s.l. during the evening.
Cloudy.

For updated info, please visit yr.no

Observations the last 3 days

Heiane / GJESDAL

Snow

11.03.2019 kl. 13:02

896 masl

Salvesen@obskorps (***)

Image Of Snow Profile
Image 1 of 14 Of:  Snow Profile Copyright:  Salvesen@obskorps
Image Of Danger Sign
Image 2 of 14 Of:  Danger Sign Copyright:  Salvesen@obskorps
Image Of Danger Sign
Image 3 of 14 Of:  Danger Sign Copyright:  Salvesen@obskorps
Image Of Danger Sign
Image 4 of 14 Of:  Danger Sign Copyright:  Salvesen@obskorps
Image Of Avalanche Activity
Image 5 of 14 Of:  Avalanche Activity Copyright:  Salvesen@obskorps
Image Of Weather
Image 6 of 14 Of:  Weather Copyright:  Salvesen@obskorps
Image Of Snow Cover
Image 7 of 14 Of:  Snow Cover Copyright:  Salvesen@obskorps Comment:  Tørr nysnø rett på asfalt 550moh
Image Of Snow Cover
Image 8 of 14 Of:  Snow Cover Copyright:  Salvesen@obskorps Comment:  Hallbrekkvæven i Hunnedalen. 500-700moh
Image Of Snow Cover
Image 9 of 14 Of:  Snow Cover Copyright:  Salvesen@obskorps Comment:  Bilde tatt mot vest 600moh
Image Of Snow Cover
Image 10 of 14 Of:  Snow Cover Copyright:  Salvesen@obskorps Comment:  Østvendt, gamle våte løssnøskred til høyre i bildet
Image Of Snow Cover
Image 11 of 14 Of:  Snow Cover Copyright:  Salvesen@obskorps Comment:  Myk sastrugi på skare på utsatte plasser
Image Of Snow Cover
Image 12 of 14 Of:  Snow Cover Copyright:  Salvesen@obskorps Comment:  Myke flak over tregrensen.
Image Of Tests
Image 13 of 14 Of:  Tests Copyright:  Salvesen@obskorps
Image Of Snow Profile
Image 14 of 14 Of:  Snow Profile Copyright: 

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 Specific steep slopes SE, S, SW above 700 masl

Dry slab avalanche Poor bonding between crust and overlying snow Within half a meter The overlying slab is soft. Easy to trigger Possible 2 - Medium Specific steep slopes SE, S, SW above 700 masl

Snow Cover

55 cm in total No snowdrift 20 cm new snow Elevation of new snow 300 masl. Snow line at 300 masl. Layered snow begins at 500 masl Much loose snow (10-30cm) Dry Det fuktige snøfallet/ regnet forrige uke har nå fått et solid påfyll av knusktørr nysnø. Denne ligger fra 300m. Under 500 legger den seg rett på barmark. Over tregrensen ligger snøen som myke flak i sørlig halvdel av kaka. Den legger seg rett på et pennehardt skarelag som merkes underliggende ved skikjøring. I bratt sør og sørvest er snøen merkbart solpåvirket.

Avalanche Danger Assessment

2 Moderate Den sist ankomne snøen er det eneste å ta hensyn til nå. Myke flak i høyden som enten glir på skare eller på løsere nedføyket. Ubunden tørr snø i bratt lende kan også gi små skred. Neste døgn ventes mye nedbør som snø i kombinasjon med kraftig vind. Dette vil trolig skjerpe situasjonen betraktelig. Forecast correct Dagens varsel oppleves som presist, men jeg tror høydeangivelsen på fokksnøproblemet kunne vært satt et par hundre meter lavere.

Weather

No precipitation -1 °C 3 m/s from W → 50% clouds Pent lettskyet og kaldt vær siste døgn.

Tests

ECTN11@20cmQ2 Medium Går på skaren.

Avalanche Activity

11. Mar. 18-24 (+01:00) Loose dry avalanche Few (2-5). 2 - Medium. Spontaneous release Specific steep slopes. S. Above 600 masl Hovedsaklig sørvendt ifm. Svaberg og fremstikkende steiner.

Danger Sign

Recent cracks Område: Generelt på fjellet. Beskrivelse: Sprekker opp rundt ski

Recent avalanches Område: I denne fjellsiden. Beskrivelse:

Recent snowdrift Område: Generelt på fjellet. Beskrivelse:

Snow Profile

7 stratigraphy layers observed 11 temperature points observed

ObsID: 185593

Heiane / SIRDAL

Snow

10.03.2019 kl. 12:14

976 masl

Stanis@frivillig (**)

Image Of Snow Cover
Image 1 of 1 Of:  Snow Cover Copyright:  Stanis@frivillig Comment:  Snødekket. Bildet mot NV

Snow Cover

60 cm in total No snowdrift 20 cm new snow Elevation of new snow 4 masl Much loose snow (10-30cm) Dry Fint, fist-myk og tørt snødekket fra kraftig snøfall på natten til søndag. Ikke mye vind transportert snø observert

Avalanche Danger Assessment

2 Moderate Opplevd veldig Stabile forhold på bakker mot Vest, Sør og Sørøst for øvrig. Myke flaker av nysnø kom på vindpakket snø, som liger over et hard skarelag Stabiliserer seg videre på mandag. Himmelen uten skyer, lave lufttemperatur og ingen vind på natten til mandag kan forårsake overflaterim krystaller dannelse, særlig på øst og nord ligende fjell, som kan danne et svak lag dekket av fokk snø som kommer på tirsdag Forecast correct

Weather

No precipitation 2 m/s from W → Lufttemperatur på -5

ObsID: 185454

Heiane / SIRDAL

Snow

10.03.2019 kl. 09:05

804 masl

Salvesen@obskorps (***)

Image Of Weather
Image 1 of 1 Of:  Weather Copyright:  Salvesen@obskorps Comment:  Fra Fidjelands instagram konto.

Weather

ObsID: 185287

Heiane / GJESDAL

Snow

09.03.2019 kl. 14:00

630 masl

Salvesen@obskorps (***)

Image Of Weather
Image 1 of 1 Of:  Weather Copyright:  Salvesen@obskorps

Weather

Snow Solid snøvær i går later det til

ObsID: 185289

Heiane / GJESDAL

Snow

09.03.2019 kl. 10:37

822 masl

Halvor89 (Unknown)

Image Of Avalanche Observation
Image 1 of 1 Of:  Avalanche Observation Copyright:  Halvor89
ObsID: 185089

The bulletin does not include a detailed text about the avalanche conditions. This is only given in Norwegian. Translate it using google translate if you like. The text result will be informative, and most likely amusing

For planning your trip and recognizing avalanche terrain, use maps.

Norway has 1:50 000 maps for the whole country. Maps can be bought at bookstores and sports shops, or printed from the net.

Visit www.ut.no for topographic maps online. For slope angle maps, see NGI slope angel maps ("helning" means slope angle).

Modelled snowpack and historic and current weather information can be found on the webpage senorge.no. This site uses information from the weather stations and interpolate values from the stations for gridded maps.

Detailed weather forecast can be found online at www.yr.no or www.storm.no. Yr.no is also in English, but the weather in text format is only given in Norwegian.