How to use Windy's forecast for mountain hiking?
m k 07e5e81f-0d33-4e0f-95f3-9d6c86e251df last edited by m k 07e5e81f-0d33-4e0f-95f3-9d6c86e251df
which forecast/s would you suggest to check when planning mountain hiking in Europe?
I noticed that Mapy.cz uses Windy's ECMWF model for forecast, but it doesn't really seem reliable - at least not with temperatures when it comes to mountain peaks. It often seems to show much higher temps than they actually are in the mountains (e.g. 10-11C when it should be 4-5C or so at such altitudes - eg. 2500m). In short, ECMWF doesn't seem to display much difference in temperature between valleys and mountain peaks, which seems rather unlikely especially now that it's gotten much colder in the mountains than in the valleys. Unless I'm missing something.
I noticed Windy mentioned somewhere that MeteoBlue (NEMS?) is useful for alpine area, but does that only apply to Switzerland?
Which models would you then recommend for weather forecast, temperatures and precipitation animation (and anything else you may suggest?)?
In mountain you should use high resolution models as explained here:
AROME and recently ICON-D2 which are covering most parts of Europe are the best models in mountain. In which region are you hiking?
Meteoblue is only available for local forecast (Meteograms) not as map and is very good in mountain. NEMS is only one of the several models used by Meteoblue, but not so performing in mountain.
@idefix37 Thanks for your reply. I'm currently mostly interested in Slovenia and parts of Italy/Austria. What would you recommend in this case?
ICON-D2 covering all countries you mentioned.
And AROME too, for northern Italy and western Austria.
Additionally Meteoblue only available for local forecasts.
The other models are useful for getting an idea about the weather in the next 3 to 4 days, the high resolution models having a short forecast duration.
You can use the comparison table by selecting Compare below Meteograms panels.
See related posts about temperature forecasting in mountain:
@idefix37 Thanks for your replies so far.
I will try to play around a bit with different models to be able to ask you more specific questions.
I'm also curious about Clouds (and High/Med/Low clouds).
If I want to check how cloudy it's going to be at a specific hour the next day, should I select "Clouds" from the sidebar, or one of the subcategories: High/Med/Low?
Also, when I select "Clouds" from the sidebar at a certain location (mountain), ECMWF model says 35%, METEOBLUE just shows the same number as the previous model I switched from, while ICON-D2 79% for a specific hour I selected. Which one is to be trusted here? 35% vs. 79% is a huge difference.
Yes, you should select Clouds. But big differences between models forecast is not so surprising to me. Cloudiness is quite difficult to predict, and in mountains there are orographic effects on clouds that all models are not able to see due to their poor resolution and their coarse orography model.
BTW you can’t see the % of cloud cover by Meteoblue which is, as already said, only available as point forecast. NEMS is a bit different from Meteoblue which is a consensus model from multimodel algorithms and local algorithms.
Concerning Low, Medium and High clouds you can look at them, knowing that low clouds are from surface to 2000m’ medium clouds from 2000m to 6500m and high clouds above 6500m as explained in the FAQ:
In Meteogram, you have the cloud forecast according to the altitude.
Interesting in mountains is to consider the Sounding forecast. Particularly for temperature inversions, which brings stratus in valley at low level with sunny conditions above. You get the sounding diagram with right click on desktop and long press in the mobile app. As example Jura mountain with ICON-D2
@idefix37 Thanks for your repllies so far! I'll have to study it a bit more to fully understand everything.
One more question: when I search for a specific peak on Windy (to check the forecast for it), is it possible to check which location the forecast actually shows the info for? Obviously, most of the time the forecast won't be for that peak in particular, but somewhere within the radius of xy km?
@m-k-07e5e81f-0d33-4e0f-95f3-9d6c86e251df said in How to use Windy's forecast for mountain hiking?:
is it possible to check which location the forecast actually shows the info for? Obviously, most of the time the forecast won't be for that peak in particular, but somewhere within the radius of xy km?
You know that weather model data is delivered at grid points.
The distance between each of this points is about the resolution of the model. For instance 9km for ECMWF or 22km for GFS.
Then Windy interpolates the values at grid points which are smoothed to display the weather maps.
So there is no way to know at which distance is a chosen point to grid points.
In addition the model integrates a coarse orography model which does not accurately ‘see’ the altitude of a location. But the difference between the actual altitude and the model altitude is provided on the Windy sounding graphic at a location (long press on mobile screen).
In this example the altitude of the peak at 2194m is considered by the weather model at 1105m. This explains the wrong temperature.