The Snow Line

I recently completed a Mountain Training Association Weather Workshop run by the Meteorological Office and I wanted to write about something that was completely new to me: Thickness Lines and in particular, the Snow Line.

Thickness lines can be found on Surface Pressure Charts (aka synoptic charts). These are the charts that have isobars on them. Isobars are lines that join up points of equal pressure at sea level. Also displayed on these charts are weather fronts. These will usually lead to precipitation of some kind.

The atmosphere is three dimensional but the charts are two dimensional. Thickness lines try to address this. They appear as dashed lines. They don't appear on the current chart (https://www.metoffice.gov.uk/weather/maps-and-charts/surface-pressure) but if you look at the chart for 36 hours into the future you will see them. Go to the current chart and click on the timeline below it three times to show the forecast for the weather in 36 hours. Here you can see the thickness lines represented by dashed lines.

At the time of writing this is what the chart looks like:

If you look closely at two of the thickness lines (dashed red lines) you can see that they have numbers on them. In the picture above, there is the number 546 over the Bay of Biscay (just to the North of Spain). There is also the number 528 over Austria. (North of that is another line without a number on. This will be the 510 line. In the South East corner there is another thickness line and this will be the 564 line.)

As you gain altitude, the pressure decreases because there is less atmosphere above you. If you started at sea level and kept gaining height, you would eventually reach a point where the pressure was half that at sea level.

Let's take the 546 line as an example: everywhere along that line, if you went to a height of 5460m, the pressure would be half of what it was at sea level. Everywhere along the 528 line, the pressure at 5280m is half that at sea level.

So if you only count the bit of atmosphere between 'sea level' and 'half the sea level pressure' these lines represent the 'thickness' of the atmosphere. They join up points of equal thickness just as isobars join up points of equal pressure.

Warmer air uses up more space than cold air. So the 546 line shows warmer air than the 528 line. If you coloured in the spaces between these thickness lines you would get blocks of air that were warmer at the bottom of the chart and colder at the top. The thickness lines show the leading edges of these sections of atmosphere. Sometimes they show these coloured regions of air on the TV weather forecasts.

These different regions of warmer or colder air will be blown about by the wind. When isobars are closely packed together it indicates stronger winds so this can lead to rapid changes in temperature. The winds tend to go in the direction of the isobars anticlockwise around areas of low pressure and clockwise around areas of high pressure. (In the northern hemisphere).

If the thickness line crosses closely packed isobars there will be rapid change. If it crosses more widely spaced isobars there will be a slow change. If it runs parallel to the isobars there will be no change as the location of the thickness line will hardly move. This is similar to the way weather fronts move. The movement of the thickness lines helps us understand whether the atmosphere is getting warmer or colder.

The 528 line is also known as the Snow Line. If you are on the warmer side of the Snow Line any precipitation is most likely going to fall as rain. If you are on the colder side, it will most likely fall as snow.

You might argue that a greater than 50% chance of snow isn't much of a forecast but this applies at sea level. If you are higher up in the hills then the likelihood is much greater.

At the time of writing (Mon 15th Jan 2024) look at where the Snow Line (528) will be by midday on Thursday - crossing the middle of France and moving slowly south!

Group Management

Keeping the group together

The other week, whilst leading for HF Holidays in the Cairngorms I gave my usual speech on the first night about sticking together as a group on the walks. After all, that is one of the reasons for booking a guided walking, group holiday. Nevertheless, on the first day, a couple walked off ahead of the group into the mist. I had to shout as loudly as I could to get them to wait. Later, one of them asked why I’d done this and I explained that if there was a problem like a twisted ankle, I needed to be able to communicate with everyone.

I could also have mentioned the effect they are having on the rest of the group but when people are on holiday it’s wrong to spread it on too thickly. The fact is however, that people getting too far ahead is demoralising for the people at the back of the group and it encourages others to go speeding on ahead as well. As the leader, I try to walk at the pace of the slower walkers or to stop frequently to bring the group back together. Having someone walking at a quicker pace in front of you, means that you have to concentrate hard on not speeding up, yourself.

People who like to go ahead of the group often tell me that they have their own pace and they find it difficult to walk more slowly. I have occasionally suggested that they could just wait for a while when we stop and then catch up, rather than going ahead and waiting for us. This would be much better for group morale but no-one has ever tried it. I think it’s because they just like being at the front. You often see couples out for a walk ‘together’ but the bloke is about 50 metres ahead of the woman. What’s that about?

I am happy for people to go ahead so long as they stay in touch with the group and wait if there is a choice of routes but some people struggle with this.

When bringing the group back together it is nice to stop at a place where you have something to say. This might be to talk about a plant or point out something in the distance. This is a good thing in its own right but it also makes it less obvious that you are having to wait for people. It is a lot easier to do this if you are near the front. By waiting until everyone is there before you start talking, not only does no-one miss out but it also stops people from setting off as soon as the back of the group catches up. This is a pet hate of slower walkers – arriving at the end of a talk and the group setting off again immediately - especially if we are going uphill and they are a bit out of breath.

Finishing on time

When you lead a walk for HF Holidays you are given a route card with estimated times for each leg of the route. This is a good idea anyway and is worth thinking about before you set out. You can use a simple formula to generate the estimate. e.g. 4km per hour plus one minute for every 10m of ascent. Obviously this can be adjusted for different groups. It’s worth explaining to the group that you are aiming to avoid a lot of waiting around at the end but that you also do not want to be late back. With practice you can try to set a pace that corresponds with your estimate.

From this formula you can work out how long the walk would take if you walked continuously without stopping. If there is a bus picking you up at a certain time then you can work out how long you have for breaks. I generally subtract 15 minutes from this for contingency and then think about roughly where and when we might take these breaks. I quite like to have a morning break (elevenses), a lunch break and a break in the afternoon where the whole group can sit down together. It’s worth reminding people beforehand to bring something waterproof that they can sit on. It doesn’t have to be a mat. A plastic bag will do.

Sometimes this just works out nicely - say 15 minutes in the morning, 20 mins for lunch and 10 minutes in the afternoon but frequently there is still some spare time left over. There are various tactics that you can use to fill this time. You really don’t want to be hanging about waiting at the end and possibly all getting cold. Of course if there is a café …

The ideal is to stop frequently to talk about the environment: plants, animals, interesting landscape features, geology, history etc. It’s quite nice if the group are chatting well together, to pause before setting off again - maybe after you’ve collected the group together or the group has stopped at a point where the path divides. Just standing there and letting people chat for a while is very pleasant.

Sometimes there are optional extensions. Maybe you can divert from the route slightly to take in a viewpoint or a bird hide?

Things are more difficult in wet or cold weather. People don’t really want to hang about but you need to persist because you know that they’ll just be waiting around at the end if you don’t use up some time now.

There are more underhand tactics of course. For example: if there are lots of gates and stiles, you can speed the group up by letting them get a bit more strung out. This way queues do not build up at each stile. Alternatively you can keep everyone together and create these queues!

If you need to speed the group up, it is worth doing things together e.g. getting everyone to stop for a drink at the same time, suggesting that we all put our waterproofs on together when it starts raining, or all taking them off at the same time. Of course you can fail to do this. Everyone will stop at different points and have to be waited for.

Going to the toilet

HF did a survey a few years ago to see what people’s top two pet hates were. One was leaders not knowing group members’ names. Because guests on HF Holidays usually sign up for which walk they will be doing the night before or in the morning, you can have a list of everyone’s names before you set out. If you run through these with the group at the start of the walk it helps you (and the rest of the group) put names to faces. Because you have the list in your pocket you can take it out and remind yourself who is who, as you go along and ask individuals for a reminder if necessary. This is harder for the rest of the group because they don’t have a list.

Half the fun of leading a hike is getting to know people. Especially older people. They usually have a fascinating history of walking or have had a really interesting career. I’m not the greatest conversationalist but it’s worth the effort. It also makes it easier to manage the group.

The other pet hate was leaders not facilitating people going to the toilet. Sometimes this might involve explaining that we will get to a café or a public toilet in half an hour. More often though it’s a case of ‘going’ outdoors. In HF parlance this is known as a Comfort Stop.

Traditionally this was always managed after lunch by a Gentleman Forward Stop. The ‘gentlemen’ would walk on ahead until they were out of sight and the ‘ladies’ would catch up when they were ready. This can still work well under certain conditions. You need to make sure no-one else is going to wander by. You sometimes have to spell out the fact that the split needs to include everyone whether they want to ‘go’ or not. Of course we are not dictating when you go to the toilet. It’s just an option.

If the conditions aren’t right it is worth looking out for a spot where the women could go. It’s easier for the men. If you don’t do this not only are you creating a ‘pet hate’ but everyone will pick their own spot and then you’ll have to wait for them to catch up. Sometimes people really do not want to have a comfort stop outdoors and consequently don’t drink enough liquid and become dehydrated. This can be dangerous in hot weather.

My Experiences With Gloves

When I was a child my gloves were knitted from wool. Mittens were warmer than gloves but not really very cool at school especially if they were joined with a long strip of elastic than ran up your sleeves! Nowadays you can pay a lot of money for a pair of gloves to wear in the mountains, especially in winter. Some of the specifications are amazing.

Take Black Diamond Women's Guide Gloves, rated second in a review of winter gloves for women in this month's The Great Outdoors magazine. They have a retail price of £160 and are "beautifully constructed from supple soft shell and goatskin, [with a] seriously warm liner glove, which is a double whammy of PrimaLoft and boiled wool insulation".

Perhaps a bit more realistic would be Dexshell Ultra Weather Winter Gloves, rated first amongst men's winter gloves by TGO magazine. Priced at £45, they are made from "Taslan polyester, textured anti-slip PU, Porelle membrane, PrimaLoft Gold with CrossCore, polyester fleece". Well, I 've heard of Primaloft but not Porelle or Crosscore (links provided if you are interested).

Over the years I have owned many pairs of gloves and I do have quite cold hands. It takes about an hour for my hands to warm up if they have got cold. My circulation system is prioritising my heart and lungs but an hour is a long time compared to most people when exercising.

For day to day use in summer, my Trekmates thin fleece gloves are fine. If it gets a bit colder, I have some slightly thicker Montane fleece gloves and a pair of liner gloves that I can also put on. This traps a layer of air between them. You can do most things with them on but despite the fact that they have "touchscreen compatible fingertips", I usually have to take a glove off to use my phone. Also managing a map or route directions can force you take one or both gloves off. Not to mention blowing your nose!

In both cases if the gloves get wet, they are still fairly warm and I can partially wring them out by clenching my fists. Nevertheless, the idea of waterproof gloves did seem attractive. So I bought a pair of 'Sealskin' waterproof gloves. At first, these were waterproof but less so with wear and tear. However, the problem is that for the reasons given above you end up having to take them off and put them back on again over wet hands. Because they have a cloth lining they are really hard to put back on. In the end you have to wear liner gloves so that you can get the Sealskins off and on and the liner gloves get wet. You've sealed the water in rather than out.

For winter use, I am currently using Ejendals Tegera Thermal Waterproof Work Gloves from workgloves.co.uk. They are a bit fluffier inside than the Sealskins so I can get them on and off more easily and the fluffiness helps to warm wet hands. They are really warm, genuinely waterproof and pretty cheap at £20. In fact all the gloves on this site are very reasonably priced. However, they do need a bit of elastic sown around the cuffs so that the sleeves of your waterproof jacket will easily slip over them.

If I am doing things with my hands like navigating or holding poles, I do find gloves more convenient than mittens but if it gets really cold, go for Dachstein Mitts. Your fingers keep each other warm and you can put your thumb into the fingers department if you want to. They are made oversize and then boiled to shrink them so that they become very close knit. They will keep your hands toasty. You could get these from Needle Sports for example. They even come in a range of colours! Wool gloves will get wet but wool does stay warm when it's wet.

Addendum: This Safety Supply Company is amazing value!

Managing Emergency Procedures and Hazards

How do you manage a situation where you are leading a group and somebody is injured or unable to move for some reason? The text book answer is to firstly make sure you are safe, secondly make sure the rest of the group is safe and then thirdly sort out the casualty. This is all very well but how would I cope?

This was why I signed up for a 'Managing Emergency Procedures and Hazards' course run by Mike Raine and recommended by the Mountain Training Association.

Walking past Ffynnon Lloer

We met by Llyn Ogwen in North Wales and walked up Pen yr Ole Wen. On the way we talked about being aware of potential hazards and trying to think ahead. We discussed a particular scenario where someone has slipped off the path down the hillside.

Put on some more clothes, get the group to put on some more clothes, get the group into an emergency shelter and make a plan. We were thinking we should go down to the casualty next - but quite honestly,  if they haven't been able to climb back up you are going to need to call Mountain Rescue.

You might as well do that straight away. If you do call them you want to have all the information that they will ask for ready. They'll almost certainly tell you to stay put but you will want to get down to the casualty, possibly with someone else so maybe it would be better to write it all down and get someone else to phone for help? 

I know from other training that this would include: your grid reference, what happened when, who you are, the state of the party, any potential hazards to rescuers, weather conditions, how well equipped the group is, and what your plan is.

Of course that's just one scenario but thinking it all through before you act is well worthwhile. What you don't want is to be cut off from the group with no phone signal. In fact, thinking about it now, if you are planning on leaving the group for a while it could be worth exchanging phone numbers with some other group members. After all, you won't be able to call the person who is on the phone to Mountain Rescue. 

Plenty of other scenarios are possible of course. No phone signal where you are, nowhere to easily make the rest of the group safe etc. However just thinking this one through has given me a bit more confidence about dealing with other situations.

Mike recommended the Blizzard products: Blanket, Bag and Survival Jacket. We tried on a survival jacket and you could feel yourself warming up. Mike said that he'd spoken to someone at the hospital who dealt with people from rescues and they said that if people arrived in a Blizzard bag/blanket/jacket they'd treat their injuries and f they didn't, they'd treat for hypothermia!

Other great kit: Dachstein Mitts, Supalite 10 Person Bothy Bag and Personal Locator beacon. An idea that I really liked was a 1 metre square sheet of 5mm closed cell foam that you could quickly put under a casualty to protect their torso from the ground. This was pretty light.

It was a great day out in a fabulous location and really interesting to talk to other members of the group who are at various stages of their mountain leading 'journey' from working towards their summer mountain leader qualification to running their own outdoor pursuits company

Looking across Llyn Ogwen at Tryfan and the Glyders

Limone - Il Finale?

We have just returned from two weeks in Limone sul Garda. I was leading walks for HF Holidays and it will probably be the last time I lead abroad.

There were about twenty guests on each week's holiday, some of whom had come all the way from the USA or Canada. There was a little bit of rain in the first week but none in the second week and it was lovely to have the warm weather just as things are cooling off in the UK. In fact it was summer when we flew out from Gatwick and it looks like Autumn now in Hebden Bridge.

Lake Garda is the largest of the Italian lakes and is very popular with kite surfers, wind surfers and paddle boarders. The transport to the start of most of the walks was by ferry and the captain often had to sound the horn to clear them out the way. There is a cable car to the top of Monte Baldo that overlooks the lake and parascenders make use of it to fly high up over the lake.

Arriving back in Limone on the ferry.

Limone was the most northerly producer of lemons at one time and to achieve this they built Lemon Houses to keep the lemon trees in. The walls of these were posts that they could put wood and glass between to keep the trees at the right temperature. Lemons were not the only citrus fruit they grew. They also grew sour orange, sweet orange, citron, lime, mandarin, grapefruit, pomelo and bergamot. Many of these were grown by grafting them onto the root stock of a sour orange tree because it was a lot more hardy.

An old Lemon House

Sadly the lemon trees were infected by gummy disease, the army took away the boards and glass for WW1, there was an exceptionally cold winter, artificial citric acid was discovered and it was easy to grow lemons further south. These all contributed to the loss of the lemon tree business. Nevertheless enthusiasts have recreated a lemon house and it is well worth a visit. As is the wonderful Museum of Tourism.

Looking south over Malcesine

This will probably be my last lead abroad. It was already the case that many provinces in Italy, France and elsewhere were insisting that local leaders be used. See my blog entry from 2019 for example. Post Brexit this now includes many more European countries including those where they speak German and Italian, the languages I can speak a little of. I'm not keen on leading in countries where I have practically no language skills so, unless the rules change, I'll just be leading in the UK.

There will be a role for a Tour Manager to meet guests at the airport, liaise with the hotel and organise social activities on an HF Holiday abroad but it's leading the walks I like most.

I have had a good run and I do entirely understand why you might not be too happy having someone fly out to your local area from the UK to lead walks when you are trying to earn a living as a guide.

Back in Bonassola

I recently returned from another amazing trip leading for HF Holidays at Bonassola. This was the sixth time I'd been there! So you can see how much I love it. The Cinque Terre is a beautiful area with its photogenic towns by the coast and the views across the sea from higher up. There is some great and sometimes quite strenuous, walking as well.

Vernazza with Monterosso in the distance

The lower paths between the towns can get pretty busy. Top tip: if someone wants to overtake you, get in by the wall and let them pass you on the downhill side. The Cinque Terre towns: Monterosso, Vernazza, Corniglia, Manorola and Riomaggiore can also get very busy, especially now you get cruise ship groups, but we try to visit early in the morning when it is quieter. Seeing the tourists is really part of the experience!

We also get away from the touristy bits and visit quiter hillside villages. We have lunch at an Agriturismo high up above Framura which is five villages connected by steps. We also do some of the classic walks, like Riomaggiore to Portovenere, returning to Vernazza by ferry.

For transport to and from the walks we use the trains. This allows for more flexibility. We can depart really early if we want. That way we are making use of the cooler morning. It can get pretty hot and did while I was there. Using trains also means you are not committed to finishing the walk at a particular time. Monterosso station even has a bar on Platform 1 with an incredible view of the other Cinque Terre towns.

View from Monterosso Station Bar

However, the best bit is Bonassola itself and the Hotel Delle Rose. Two railway stations north of the Cinque Terre, Bonassola is a lovely peaceful place where Italians from the busy cities take their holidays. The hotel is run by the sons of the footballer Giorgio Bernardin who played for Inter Milan and Italy and they couldn't be more friendly. You can find out more of the history here.

The Roof Bar is a great place to sit in the evenings. You can eat breakfast there as well as listening to us describe the next day's walking. In the evening you can stroll out to the Punta Della Madonna and look back at Bonassola in the moonlight.

Bonassola from Punta Della Madonna

To finish, here is a picture of a prickly pear flowering over the Ligurian Sea.

Prickly Pear in Flower

Movement Masterclass

This week Dorothy and I attended a 'Movement Masterclass' in the Lake District. This was given by Chris Ensoll. Following on from my last posting about Gait, Chris also talked about the way we can use our legs as springs and use the momentum from the previous step. 

If you have a big step up you can go down a little and then step up. This allows you to use the leg you are standing on to push up rather than the leg you are about to use to pull you up. You can see Chris demonstrate this here.

He said that many people take too long a stride and that by taking shorter steps on the flat you can strike the ground using your mid sole rather than your heel, thus reducing the impact. We should stand up "straight and strong" and be "fluid and dynamic".

Something I really need to concentrate on personally is keeping my shoulders back and my chest out. You can feel your stomach flatten if you do this and it helps to engage your core.

When walking up or down a steep slope it helps if a line drawn through both your hips is at 45 degrees to the slope, with you facing downhill slightly. This allows you to put your feet at the same 45 degree angle, with the toes pointing downhill - allowing your heel and the whole of your foot to be in contact with the ground. You can see Chris demonstrate this going uphill here. On scree you should try to keep moving, in order to stay dynamic and cope with the scree moving as well.

Taking a break on steep ground

In a previous post on using walking poles, I recommended reaching forward and planting each pole in front of, and below you. This is based on advice from the British Mountaineering Council. Chris is not keen on this. He feels that it makes you lean forward too much and stops you from driving your movement from the hips. He is keen for people to avoid using poles going downhill if at all possible. This way you are strengthening the muscles around your knees. If you must, use the pole for balance by descending diagonally and holding a shortened pole next to your uphill hip so that it just touches the ground uphill from you. Change hands as you zig-zag down - similar to the way you would use an ice axe.

I will definitely try this but if someone is feeling very tired, I think it would be hard to dissuade them from putting some of their weight onto downhill poles. Going uphill you naturally hold the poles by your hips so no issues there.

I would really recommend the course. You might think that you learnt how to walk when you were about one year old but most of us have had years of learning to slouch since then and a course like this sets you back on the right path - so long as you practise the techniques.