Weekly report from HAT - 06/02/08
The last 7 days have been characterised by a series of modest snowfalls with some sunshine and mildish weather in between. As a result, the recorded snow depths high up have increased by 20-40cm.
This has produced a great improvement compared to the wind packed sun crusted conditions we were experiencing last Tuesday and Wednesday.
The risk is that slabs that were formed when we had strong Foehn winds were covered by more snow early last week and could therefore create some medium size avalanches. The risks of triggering these avalanches are bigger around ridges and convexities. (See Andreas report below)
Reports from high up (above 2750) include references to bottomless powder. Reports from below 2100m suggest the snow is humidified or even crusted a bit. South facing steeper slopes that had crusted in the sun before do not have enough new snow on them, so you can ski them, but you will hit the old crusted layer quite often.
The good news is the base is quite stabilised compared to last season, there is no widespread weak layer of depth hoar, but caution is still required.
The are two recurring themes this season. The situation is constantly complicated by the wind. Yet again we have had snow falling with wind from the south east and then followed by wind from the west. This means you have to really observe where the wind has blown the snow and where any wind slab exists.
Also it has often been the case, that the risk level in the avalanche bulletin is a forecast and not always what the guides find when they get out there. This week some areas reported a risk level 4 on Tuesday and then a risk level 3 today. Then the official position for tomorrow is risk level 2. However reports from Tuesday say that it was not a risk level 4. There was little sign of natural avalanche activity.
The forecast is for a large high pressure to come in a re create springlike conditions with mild sunny afternoons and a good refreeze each night. So the best off piste will be North East to West and high. South East to SW will be sun affected. The February sun may well not be strong enough to create a true "spring snow".
The long term models suggest more unsettled weather from 15th February (we shall see?)
HAT team activity
Andreas is doing follow up courses on snow in the afternoons where we look at the practical sides of the things we talk about at the avalanche talks. If you are interested call us on 020 8144 5202 or email [email protected]
Roddy is helping out Henry with snowboarders on an avalanche awareness course this week.
The Thursdays in depth talk has slightly changed to a "RECCO show" with Fab talking and showing an great DVD for free so check that out as well!
Tip of the week
Our tip of the week this week is about the need to not rely on the official declaration of the risk level, but to take that as a start point and use your judgement. the avalanche risk is a forecast, it could better on worse than this when you get out there. Also there wil be local effects Which make some spots more or less risky. If you have been following the history of the wind the sun and the snowfall, you will find it much easier to interpret where the risks are than if you have not done this. (we have discussed this in previous ezines)
If they say it is a risk level 4, it does not mean you cannot go, it means you have to work out where the high risk is, the high risk is likely to be in many places. Look out for signs of natural avalanche activity, work out where the wind loaded slopes are, be careful wind skiing on or under slopes above 30 degrees, remember to go one at a time and gather in islands of safety.
If they say it is a risk level 3, then there are still considerable risks (level 3 means "considerable") but they are less prevalent than in a risk level 4. With the current conditions, the highest risks will be on steep Northish slopes that are wind loaded and south slopes that have been subject to sunshine and creeping and gliding slides.
It is risk level 2 (Moderate) tomorrow as the recent snowfalls are settling rapidly. the places to look out for are the same as we mentioned above, but the number of these where there is a risk is reduced.
Remember that avalanche risk 2 is associated with a disproportionate number of accidents due to people being over confident.
So be careful, study the bulletins (on our web logs.) and read ski diaries from Andreas Henry and Wayne Watson of Alpine Experience
Future ezines will be on Wednesday evening or Thursday - next one on 6th February
Regards. Chris Radford - HAT ezine editor
Henry's Avalanche Talk - Now in London
When: Thursday February 21st 7pm
Where: GJ's Bar & Restaurant 89 Garratt Lane, Wandsworth, London SW18 4DW
To book call: 0870 850 8892 or Email: [email protected]
Skiing with HAT
We have opportunities to ski with Henry. In all these programmes you will develop better off piste skills and increase your confidence to stay safe and have fun out there. They are all about getting out into the off piste and having more fun and building confidence.
We can sell places for 1 day or 2 days if a full programme is too much or just too inflexible for you. Costs are around £100 a day per person or £70 for just a morning session.
We can organise special teens and family groups in the school holidays call us in UK +44 20 8144 5202, to enquire.
Snow report from Andreas
Hello all, What a season we are having. We were just getting desperate for some more snow and it arrived, giving us some more great powder skiing.
So how about the stability? Well, the long spell of good weather at the end of January meant that the base of the snow pack is pretty well stabilised either by settling, melt-freeze or skiers compaction. I would be very surprised to see slabs triggered down to the ground, apart from the "creeping and gliding" avalanches that we have seen on southern expositions all season.
The situation got a bit more complicated last week with snow, then wind, then snow again and the wind changed direction all the time. The risk is that slabs that were formed when we had strong Foehn winds got covered by more snow early last week and could therefore create some medium size avalanches. The risks of triggering these avalanches are bigger around ridges and convexities.
From Thursday we should have some nice and warm weather so most of the slabs will have settled and the forecast is for a high pressure with quite warm temperatures which will help settling the snow again, ready for some more snow on top! Bring it on!
Have fun and be safe.
Andreas - Alpine Experience / HAT Mountain safety
We are doing follow up courses on snow in the afternoons where we look at the practical sides of the things we talk about at the avalanche talks. If you are interested call us on 020 8144 5202 or email [email protected]
The Thursdays in depth talk has slightly changed to a "RECCO show" with Fab talking and showing an great DVD for free so check that out as well!
Recent Reports from our snowboarding coach - Roddy
February 04, 2008
More New Snow. Although I was on piste all morning and visibility was poor, there was a fresh covering of snow on all the runs. This coupled to the 10 to 15cm of snow over the weekend can only lead to conditions improving in the off piste. Im looking forward to better weather tomorrow so I can go exploring and check out what its like.
February 03, 2008
A full day off-piste: After a foggy Saturday and 10 to 15cm of new snow we made a real effort to get some fresh tracks today. We did several of the major routes including tour de charvet and the grand vallon. We found that if the terrain was too steep we hit the old melt freeze layer but on the shallow slopes the snow was real light and fluffy and fun to ride. As the day went on it became very cold and windy and this was starting to effect the snow making it heavy and harder to ride. Not the most amazing day off-piste but a vast improvement and just really nice to get back out there away from the pistes and the crowds.
Tignes weather forecast: Feb 7th to Feb 11th.
Status and trends: At least five days of clear weather tomorrow. The clouds of the North should soon give way tonight.
Tomorrow, Thursday, February 7
Night clear, good night refreeze extending with a strong north wind. Temperatures are comfortable immune to the kiss, which retains all Day.
Pressure 1035 mb In plain: 0 / 10 ° C, wind NE / 4 knots At 1500m above ground: -3 -> +3 ° C, wind north-> NE/10 knots At 3000m above ground: -4/-2 ° C, wind Nord/34-> 20 knots Iso 0 °: 1000 -> 2500 ISO -10: 4400m
Friday, February 8
Skies clear in the mountains, night and day. The north wind is weaker, but Iso 0 ° still too high for the season. We can not exclude rare nighttime fog wetlands. Mb pressure 1032-1036 In plain: -1/12 ° C, low wind At 1500m above ground: 3 -> 5 -> 0 ° C, wind ENE / 7 knots in the morning At 3000m above ground: -2 ° C, wind NNE/20-> NE/16 knots Iso 0 °: 2600 -> 1600 -10 ISO: 4500
Saturday, February 9
Still no clouds and only slightly less hot. Pressure 1035 mb In plain: 0 / 12 ° C Wind SE / 6 knots in the morning At 1500m above ground: -1 -> +3 ° C Wind SSE / 6 knots decreasing At 3000m above ground: -3 ° C, wind NE/15-> 8 knots Iso 0 °: 1300 -> 2200 -10 ISO: 4500
Sunday and Monday
Good weather.
