your experience with weather forecast / apps / accuracy

Hi Ralph, 

CO2 and earth warming brings more and more energy to our atmosphere. Outcome is the loss of stable weather. That makes weather forecast more complicated, in some years perhaps impossible. 

This is my opinion and expirience. 

CS 
Frank

I believe we have to live with the fact that a forecast for cloud coverage is even more difficult than a normal weather forecast. Even if you get the trend right changing wind conditions may let the clouds arrive somewhat earlier or later. In general I look at meteoblue and clearoutside too. In case they agree my experience is that you can rely on the result. If they disagree it gets tricky because I wouldn't claim that any of them is more reliable than the other. Usually if one of them predicts good conditions I prepare for the session and then decide in the evening based on my own look at the sky. In general I'm quite happy with these two services. What I would wish for is in addition to percentage of cloud coverage to get additional info about what type of clouds to expect. 30% coverage with nice compact cumulus clouds still leave you plenty of space in between to catch some targets, with 30% cirrus you can just forget about any imaging or star gazing. But maybe this is even more difficult to predict?  I believe getting surprised by the weather in a positive or negative way is part of this hobby.

I don't think that geopolitics influences the mathematical models  but I'm open to learn that I'm wrong. Since climate change increases the energy in the atmosphere which results in increased dynamics - by the way one of the reasons why "global warming" can lead to colder winters and heavier snow storms in some regions - it's quite possible that predictions get less reliable.

Clear skies
Wolfgang

Hi Ralph,

I use this app called 'Windy' on my android phone. It is not made specifically for predicting astronomical seeing, like clear outside, but provides 5 different weather forecast models for your specific area which you can check and compare. The other features like satellite images to see cloud movement, pressure, wind, rain, snow prediction etc are also there. I am using the free version of the app but there is a pro version of the app. There is lot of customization you can adopt depending on your requirement. Generally, I tend to go with whatever majority of models are predicting and found it to be fairly accurate.

Clear skies!
Rajat

I‘m using meteoblue and I find that it’s very reliable. It’s not just the prediction that matters but also if one knows how to read the predictions.

What makes meteoblue suitable IMHO is that they are very transparent in their predictions: if you’re using the multi model predictions, you can assess how far ahead a model/simulation is looking. In addition you can see by how much the models agree. E.g., If they split 50/50, it will (a) tell you that there’s uncertainty and the odds can be estimated.
Another source is the satellite film that should help a lot for short term assessments.

Regarding geopolitics: yes it matters. If you don’t exchange measurement data, your lacking input for your models.

Björn

Hi Ralph,

I live in Belgium and use a bunch of apps and websites to check. Like kuechlew says, i compare the data these alle give me.
For instance i always check clearoutside first with meteoblue aswel. Then i check the wheater app from the royal meteo institute from Belgium, called K.M.i.
If the data these give me is equal, i go check a couple of websites. For example, sat24 and wolkenradar.nl for cloudcoverage.
i my humble opinion there is not 1 to rule them all. Clearoutside has been "wrong" many many times, aswel as the kmi app.
And on tv i always check the regional channel for the local wheaterforcast. They are mostly right  

hope it helps
greetings

Looking outside is the best.  I have used several and they all lack when it comes to cloud cover, the one and only thing I worry about.  Outside of just looking and watching, using  a satellite view.  

AS to the global warming person, I seriously get it, global warming is bad, we need to do something about it, but weather forecasting has never been good, weatherman are like baseball players except with a worse average. 

Global warming OMG SMH. Have to admit it was a good read!

I use Ventusky in combination with Meteoblue. Both are very accurate.

I would suggest you first try to understand your own conditions from what forecasts you have available–look at forecasts and then go out and look at the sky. I don't think there is any one best solution, it depends a lot on where you are located, and for sure each forecast has its own bias. So I look at many forecasts for different sources to plan ahead, from experience I found some predict too much cloud, some predict too clear. You will have better luck if all your forecasts agree–but that is not that common.

But in the end I mostly depend on the satellite IR view, which is usually about 20 to 30 minutes behind realtime–I look for the movement of the clouds around my location, and watch carefully to see how the clouds are evolving as they move toward my location–are  the clouds are breaking up as they move in, or they are closing in? You might see horrible clouds coming but they are disappearing as they get closer, which is great, or it looks clear, but clouds are popping out of nowhere locally, which is not good.

It seems to me any published forecast is not very up to date. They say it is still cloudy when it has cleared up and vice versa, and the forecasts are  not nearly local enough–it can be clear 20 km away and totally clouded over locally, so I can predict much better by watching the satellite images progress in the evening before it gets dark. You get to have a feeling for it eventually.
Rick

Clearoutside is usually pretty good 12 hours out. I always check Windy for a more detailed cloud cover forecast.

Dear Olaf and the rest of the communicy,

thanks for all your statements and experiences. I collected further informations and indeed it was stated that the forecast is created by 80% by satellits, 10% by airplanes and 10% by terrestic stations. 
Ralph

Agree with everything said by everyone above. All great apps and recommendations.  In my more limited experience, all of the predictive models, regardless of where you are or what device/app/model that you use, nothing beats using those tools as a guidance as to when it is worth looking outside and preparing to shoot.  I will use the models to determine if it is worth setting up the gear, then go out 30 minutes before I would customarily start thinking about polar alignment and assess whether conditions merit go or no go.  I use Astrospheric and Clear Outside here in the Midwest, then look at real-time radar models, then decide.   However, nothing beats looking with your own eyes though as you get to go/no-go decision time.  It is not unusual for models to suggest suboptimal conditions yet find clear skies, and at other times, models predict clear skies only to find clouds.