Avalanche forecast for Indre Troms Sunday 2019-04-21

3
Considerable
Published:

A very complex situation is at hand. Rain will weaken the snowpack below treeline. In the alpine new snow and strong winds will form unstable wind slabs. The old persistent weak layer may still be triggered after being weakened by the last days raining event.

Wind drifted snow (slab avalanches)

Poor bonding between layers in wind deposited snow

Avoid steep (more than 30 degrees) areas with fresh wind deposited snow, especially convex terrain. An avalanche is easier to trigger where wind slabs are thin or soft. Look for areas where the wind recently has deposited snow, typically behind ridges, ribs and in gullies. Remember that local wind effects will cause variation in where the wind slabs occur.
3 - Large
Low additional load
Specific steep slopes
Possible

Wet snow (loose snow avalanches)

Loose snow

Avoid avalanche release and run out areas. Wet snow avalanches tend to release spontaneously. Timing is important. Stability decreases when the snow surface gets wet and soft.
2 - Medium
Spontaneous release
Specific steep slopes
Possible

Wet snow (slab avalanches)

Buried weak layer of faceted snow above a crust

Avoid avalanche release and run out areas. Wet snow avalanches tend to release spontaneously. Stability decreases when the snow surface gets wet and soft. Timing is important.
3 - Large
Spontaneous release
Isolated steep slopes
Possible

What are avalanche problems?

Observations the last 3 days (map placed)

2 mm precipitation.
Strong breeze from southwest.
0 °C to 4 °C at 1100 m a.s.l.
Plus degrees up to 1400 m a.s.l. during the afternoon.
Partly cloudy.

For updated info, please visit yr.no
6 mm precipitation, up to 15 mm in the most exposed areas.
Moderate gale from southwest.
-3 °C to 1 °C at 1100 m a.s.l.
Plus degrees up to 500 m a.s.l. during renoon.
Cloudy.

For updated info, please visit yr.no

Observations the last 3 days

Indre Troms / BARDU

Snow

20.04.2019 kl. 17:19

933 masl

mbie@obskorps (*****)

Image Of Tests
Image 1 of 2 Of:  Tests Copyright:  mbie@obskorps
Image Of Snow Profile
Image 2 of 2 Of:  Snow Profile Copyright: 

Weather

No precipitation 4 °C 4 m/s from SW ↗ 95% clouds Varm fønvind ved start. ca 4 m/s vind på 900moh.

Snow Cover

125 cm in total No snowdrift 0 cm new snow Elevation of new snow 1400 masl. Snow line at 0 masl. Layered snow begins at 700 masl Wet loose snow Wet Snødekket er smelteomvandlet helt til bunns opp til 900moh. Myk våt løssnø opp til 1200moh.

Avalanche Activity

20. Apr. During the day Loose wet avalanche Few (2-5). 2 - Medium. Spontaneous release Specific steep slopes. N, NE, E, SE, S, SW, W, NW. Below 1100 masl Det er observert noen våte løssnøskred og et vått flakskred i Vesleala og Storala ved Setermoen i dag

Avalanche Problems

Wet slab avalanche Buried weak layer of faceted snow near surface Over one meter A big and identifiable crystal in the weak layer. Difficult to trigger 3 - Large N, NE, E, SE, S, SW, W, NW above 1100 masl Der smelteomvandlingen ikke har nådd ned til kantkornlaget og brutt det ned enda, vil det kunne gå store til svært store våte flakskred. Forventes over 1100moh.

Loose wet avalanche Loose snow Easy to trigger 3 - Large N, NE, E, SE, S, SW, W, NW below 1200 masl Snødekket er smelteomvandlet helt ned til bunn ved snødybde 125cm på 900moh. Kantkornlaget over skare er delvis brutt ned grunnet smelteomvandling. Ingen bruddforplantning, men der snødekket er tykkere og høyde over 1100moh kan det fortsatt være mulighet for brudd i kantkornlag ved den økende belastningen det våte snødekket gir.

Tests

ECTN28@65cmQ3 Good snødekket er vått helt ned til bunn.

ECTN28@65cmQ3 Good

Avalanche Danger Assessment

3 Considerable stabiliteten i snødekket er god opp til 900moh. Vått snødekke opp til 900moh gir mulighet for våte løssnøskred. Det er observert flere middels til små løssnøskred i strekningen Sørreisa til Setermoen i dag. Over 1100moh forventes det fortsatt kantkorn dybt i snødekket som kan gi store til svært store våte flakskred. Værmeldingen for de neste 24 timer tilsier snø over 1000moh noe som kan gi svake lag i fokksnøen da det er meldt 10m/s. Fortsatt mildt under 900moh gir fortsatt fare for våte løssnøskred. Været tilsier nysnø over 1100moh og mildt under 900moh Forecast correct

Danger Sign

Quick temperature change 12 grader på 80moh. 4 grader på 900moh

Much water in the snow Mye vann i snøen helt opp til 900moh

Recent avalanches noen ferske våte løssnøskred observert mellom Sørreisa og Setermoen i dag.

Snow Profile

5 stratigraphy layers observed 12 temperature points observed 1 Tests connected to snow profile temperaturgradient viser at smelteomvandlingen ved 900moh går gjennom hele snødekket.

ObsID: 192035

Indre Troms / BARDU

Snow

19.04.2019 kl. 13:05

891 masl

perheimdal (***)

Weather

Snow

ObsID: 191871

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.