How to read a mountain forecast properly

A mountain forecast should state which elevation it was computed for. If it does not, it is probably using the model's average height for that grid cell, which may have nothing to do with where you will be skiing.

The ski area at Erciyes runs from 2,088 m to 3,346 m. In dry air you expect roughly 0.6-1 degree of cooling per 100 m, which puts a typical 7-12 degree difference between the two ends.

This is why the panel on this site shows two points separately. Read the figure for the elevation you intend to ski; an average represents neither end.

Most forecasts show average wind speed. On a mountain the gusts matter more: what usually stops a chairlift is a sudden gust, not a steady breeze.

When the gap between average and gust is wide, expect intermittent lift operation. An average of 20 km/h with 60 km/h gusts is riskier than a steady 30 km/h with 35 km/h gusts.

Wind's second effect is on perceived temperature. The same thermometer reading is substantially more dangerous to exposed skin on a windy day.

Temperature and wind come as numbers; visibility does not. Yet losing visibility is the most common thing that ruins a day on a mountain.

The best available proxy is the weather description: overcast, fog and snow showers all point to difficulty reading terrain up high. If a source publishes a cloud base height, that is a more direct signal still.

Visibility can be poor even without precipitation. Dry snow lifted by wind cuts visibility as effectively as falling snow, and Erciyes has plenty of dry snow and plenty of exposed terrain.

The first two or three days of a forecast are markedly more reliable than the rest. Days further out give you trend rather than values: "colder on Friday" is usually right; "minus eleven on Friday" is not.

In mountain terrain that uncertainty grows. The model represents the ground at limited resolution, so valleys, ridges and local wind effects are not fully captured.

The practical approach is to read trend for the distant days and values for the near ones — and always check again immediately before you travel.

The type of precipitation matters as much as the amount. Near zero degrees, a forecast saying "precipitation" can mean snow at the summit and rain at the base — the same system producing two different days at the two ends of the mountain.

Humidity determines the character of the snow. Dry, cold air produces the light powder Erciyes is known for; when humidity rises, the snow gets heavier and packs faster.

These two lines are the ones most often ignored, yet they largely answer the question "what kind of snow will there be today".

A forecast is an input, not a conclusion. The real question is which elevation, which aspect and which hour you should ski given those numbers.

If wind is high, leave the upper lifts until later or stay low. If visibility is poor, drop below the treeline. If temperatures are above freezing, start early and use the firm surface before it softens.

Those three rules turn forecast numbers directly into a plan. Reading the numbers and changing nothing produces the same result as not reading them at all.