Weather for hill walking – what information sources should I use for looking at the weather forecast before a hill walk?
‘Some countries have a climate and we only seem to have weather’ is often heard in Lake District pubs after a wet day on the hill as people steam dry by the fire.
According to the Met Office 31% of people have got into perilous danger through not checking the forecast and 80% say checking the weather is not a top priority before heading out. And only 38% use a forecast suitable for their target environment i.e. Mountains.
I must say find that odd as I meet a lot of hillwalkers and weather is a big topic of conversation in car parks and pubs, and as for sources MWIS is often quoted enthusiastically. With pilots I’d say checking weather is more of an odd obsession in the UK.
As for what sources to check, these come into two categories. Online and the Mark I eyeball. Yes, research online before you go, but every hour or at every rest point, as you check your group and the conditions, look at the weather and where it is coming from.
Confession time. After working at home, I grabbed my fell running hill bag and headed into the Peaks wearing sunglasses and earphones enjoying the frosty clear blue sunshine. I didn’t look behind me. 90 minutes later I had turned around and was running off wearing full gear, snow goggles through an inch of snow and into a 35 knot head wind. Look where the weather is coming from, as well as what you are stood in now.
APPS and Websites
- Wind and gust with a choice of units (mph, kph or knots)
- App covers multiple common Smartphone/Tablet platforms
- Rainfall with basic moving weather map for last 6 and next 24 hours
- Pressure, humidity, and visibility (basic vis.)
- Sun rise and sunset time
- UV (I always forget sun cream. Summer in the Peaks was a Thursday last year)
- Video forecast.
- Freezing level
- Feels like temperature
- Chance of cloud free summits percentage
- Outlook by hour and by day
- Push notifications of weather warnings – Yellow means ‘Keep an eye on it, prepare’, Amber means ‘Take serious note and action’, Red means ‘Danger potential of loss of life, stay in the pub’. (I may have made the last part up).
MOUNTAIN WEATHER INFORMATION SERVICE – MWIS
Similar information to the Met Office.
The MWIS App is only Google/Android though.
MWIS does have an online video and talk through synoptic (weather chart) whereas the Met Office is just surface pressure and rainfall and a video of the forecaster.
There are many others to make your own choices from –
- Weather Pro by Meteo Group
- Mountain Weather UK App costs £4.99 (at March 2018)
- Mountain-Forecast.com, US based but covers some UK ranges with maps of wind, temp, precipitation etc.
Weather RADAR a free app and some auto weather stations are available online too e.g. Cairngorm. So, lots of choice then.
MWIS forecast used to be fantastic for the Peak District but they merged the Peaks forecast with the Yorkshire Dales it and seemed to lose some accuracy. The Met Office Mountain Forecast website is clean and easy to use, even showing some ‘Mountain Tops’ forecasts, and you can get to a synoptic if you want to, but anecdotally people seem to think MWIS has the edge on accuracy. I use both.
The key features to note are –
- Temperature at different levelsand feels like temperature ; freezing level
- Sun rise and sunset (if your navigation is not good in the dark to get off in daylight)
Why is wind so important and why do I need a Mountain Forecast instead of the BBC’s Keswick town centre forecast?
Generally speaking temperature falls with height but wind speed tends to increase. So, stood in the car park in Wasdale getting ready to go up Sca Fell Pike, it is not too bad at zero degrees.
Temperature drops as we climb between 0.4 and 0.9 degrees Celsius every 100m (depending on whether the air is dry or damp). If you prefer old school like me, a rule of thumb of 2 degrees per thousand feet on average is about right. So, on top of Sca Fell Pike altitude alone will drop the temperature to around – 6c.
If the forecast says 30 knots on top gusting 35, the wind chill will make it feel around -17c (feels like). A tad parky, you may need your big coat.
(Tip don’t layer up in the car park for the climb, you sweat and then cool off. Better to start a little cool and walk up hill steadily to warm up. Then layer up at the top or when you stop nice and dry).
Mark-I eye ball – watching the weather basics!
Research is great but also keep an eye on the weather and where it is coming from, usually from the West in the UK but we can get bad conditions from the East. ‘What did it do yesterday, how is it looking now, what’s coming our way?’
Use your altimeter watch if you have one or an app to check the pressure, a gentle rise or fall in barometric pressure tends to mean stable weather. A rise in pressure usually means clear and more stable conditions are on the way.
If the pressure is falling by 3 (mb or hPa) or more in 6 hours, we may be in for wet and unsettled weather. The faster the pressure change the stronger the wind is likely – if it’s dropping like a stone, time to head for the pub.
(Tip – In the UK if you want to know where the low pressure is put your back to the wind and hold out your left arm from your side. Your left arm is pointing to the depression or low pressure area and your right arm will point towards high pressure area.)
A cold front (triangles) is the front edge of colder air probably brining a narrow band of heavy rain somewhere up to 200km in front or behind it. The triangles show the direction that the front is moving.
A warm front (semi circles) may bring a wide band of drizzle or heavy rain around 400km ahead of it. A mix of both triangles and semi circles is called an occluded front where a cold front overtakes a warm front and often means heavy rain.
Many thanks to The Met Office @MetOffice and all credit for their service and great content.
The Ultimate Navigation School is a charity providing navigation training to hill walkers, with all our net profits supporting the following charities –
Mend Our Mountains, Fix the Fells, John Muir Trust and Mountain Bothy Assoc.
Why not book a hillwalking navigation course now and get 10% off by using Trail18s in the discount voucher code at checkout?
Courtesy the Met Office UK
We train Ordnance survey champions
Weather sayings –
We have all heard ‘Red sky at night, Shepherd’s delight, red sky in the morning, barn on fire’. Or was it red sky in the morning sailor’s warning? No matter, this one is usually right as are some others, but don’t take weather sayings too seriously. Mine for the Peak District is ‘whatever type of bad weather you can think of, wait half an hour and you will get it’.
While on the subject of taking things with a pinch of salt, any forecast in UK Mountains can be incorrect as it is extremely complex to model, so prepare for the worst and hope for the best. A forecast over 18 hours in the future starts to get more like a ‘guesstimate’.
The Met Office and BBC have some great free courses, videos and guides to the weather if you are interested.
On your next walk why not identify a few clouds from this guide and see what weather they bring? As visitors to the UK often say we Brits are obsessed by the weather! http://downloads.bbc.co.uk/tv/greatbritishweather/cloudspottingguide.pdf
Thanks to The Met Office, BBC and MWIS for their great work predicting the UK weather and providing great free information.