Last night the wind picked up and the forecast is for a wild few days. Living near the sea the windows were rattling and they are forecasting a big storm from the effects of Hurricane Caroline. When I am asked what have been your scariest moments on the mountains in my top 10 is pals getting blown over on call outs. On pal was dropped off with me of Beinn Alligin on a big search the winds were about 50 – 60 knots and as soon as the helicopter left he was blown about 20 feet by a gust, he was lucky. If it had not had been a call out we would not have been there. Give wind great respect and add blown snow and you can have a serious problem.
7 December, 2017 – This is from the MWIS website for the Cairngorms.
“Exceptionally severe Scottish Highlands: storm or hurricane force upland
winds (strongest N/E), considerable snow (centred western hills) giving
sustained whiteout. Upland gales elsewhere and progressively dropping
temperature will result in showers being increasingly of snow.
British Mountain Summary:
Based on forecast chart for noon 7 December, 2017
Headline for Cairngorms NP and Monadhliath
Very severe: Hurricane force winds; heavy snow; sustained whiteout.”
The Met Office is very similar – Weather
Very stormy conditions with gusts over 100mph on high ground, easing slightly during the afternoon. Snow or hail showers becoming frequent through the morning with blizzard conditions and a small chance of thunder, showers merging at times. Rain showers at low levels through the morning and early afternoon then snow to most levels.
Time to take it easy and hope it all goes with as little damage as possible, definitely not a day for the mountains.
FORECASTING WIND SPEED AND DIRECTION
General wind direction is forecast, but can vary locally, particularly when speeds are light. Wind speed can also vary, sometimes within a few strides, as the air blows over a ridge or summit. Forecast speeds are where exposed, and thus will be an overestimation overall – although locally on some very exposed crags, may be an underestimate.
Mountain winds are frequently above the normal speed range experienced, particularly in inland cities. Thus, we major on describing the impact of the wind. Words used are varied but are based on the tables showing the effect of the wind on you and surroundings and wind chill.
Wind speeds from Mountaineering Scotland !
We use a wind chill of 12 degrees Celsius as the limit for specific mention of wind-chill in the text – except on the rare windy days in July and August, when with the expectation of people on the mountains in ‘summer’ clothes, we lower the figure by a couple of degrees (especially if there is a sudden change from warm weather).