arj1 wrote:
Where would you find cloud base?
I’ve tried both windy.com and SD, checking it for now and comparing it with the METARs and quite often it does not match.
So where would you go?
I can’t comment on SD as I don’t use it, but on windy vs. Metars: It is depending on what you are looking for. METARS and Windy even theoretically can’t match (except for cases where it does by chance) because they are showing completely different data.
Windy shows a forecast that is calculated by a model (always! even if you look at windy for now what you see has nothing to do with reality but the forecast data that was calculated at some point in time in the past).
METARS are a current observation. They say how the weather actually has been at the time of the observation.
Malibuflyer wrote:
arj1 wrote: Where would you find cloud base? I’ve tried both windy.com and SD, checking it for now and comparing it with the METARs and quite often it does not match. So where would you go?I can’t comment on SD as I don’t use it, but on windy vs. Metars: It is depending on what you are looking for. METARS and Windy even theoretically can’t match (except for cases where it does by chance) because they are showing completely different data.
Windy shows a forecast that is calculated by a model (always! even if you look at windy for now what you see has nothing to do with reality but the forecast data that was calculated at some point in time in the past).
METARS are a current observation. They say how the weather actually has been at the time of the observation.
I get it, but the point I was trying to make is that even a VERY short-term forecast (windy.com for right now) was not particularly precise.
Cloud bases are all incorrect, quite often some areas show “no data”, grey colour.
All I’m trying to find is how do you find data for now and/or short-term forecast?
METARs also sometimes give any weather expected in the next 2 hours.
There are several ways of getting an idea of the cloud base on AeroWeb, but naturally it is always going to be an approximation, when it is a forecast. On some I information when planning an IFR flight one has to be make sure whether the information you are seeing is height or altitude. Given a ceiling on an ILS for instance of 200ft it’s worth double checking that on the system you are using, that that is a height and not an altitude. You might well otherwise be cancelling perfectly flyable approaches.
Malibuflyer wrote:
In case of a weather related accident, however, the investigators obviously check how the pilot briefed the weather. Some of the weather services (like most of the former mandatory national services) have the advantage, that they log the use by pilots. If, e.g. I use the German national “flugwetter.de” the investigators can exactly track when I was there and which pages I saw.
The same goes for Homebriefing or Skybriefing.
Another way to ensure this, at least partially, is to keep a printed briefing folder with you all the time. That is what I do most of the time, while the briefing from i.e. Easy VFR comes as PDF, I print out the necessary pages. In quite some accident investigations, these docs are presented as found in the wreck.
If one is really interested in weather, I can wholeheartedly recommend “flugwetter.de”. It is probably the most complete meteorological work station you can get as a pilot and includes products like “advice” and pretty much everything you can find for flying in Europe. Yes, it is not free but you get plenty for your money.
Other than that, quite a lot of flight planners and briefing platforms offer weather briefings of various quality.
arj1 wrote:
Where would you find cloud base?
I’ve tried both windy.com and SD, checking it for now and comparing it with the METARs and quite often it does not match.
So where would you go?
METARS are one way, TAFs as well. Remember that those products show cloudbase AGL! For VFR, various GAFOR products do not show the cloud base directly but implied by the minimum altitudes of the various sectors/routes. Also Gramet products give some cloudbase forecasts.
Windy has cloud base forcasts using ECMWF modelling. Those I checked pretty much correspond to the METARS in that region, taking into account that the modelled ceiling would be BKN or OVC. Being a model, and in case of ECMWF a not very high resolution one, discrepances can obviously occur. However, it gives a pretty good quick look at where cloud bases are of concern.
Windy is indeed a very capable platform giving most parameters you would need, present weather as well as forecasts with an impressive array of models.
All it lacks are the official forecast products, primarily SWC’s and other forecast charts which I still think are a quite useful tool, as most of the GA relevant ones are still produced by humans as opposed to model forecasts. The French TEMSI/EUROC, the Alpine LLSWC issued by Austrocontrol/Meteo Swiss in particular are still quite valuable tools to determine the actual dangers active in the areas. The largest collection of products are available on flugwetter.de which I personally still look at as the best platform available to pilots in Europe for the sheer quantity of products available.
flugwetter.de of course has all of those,
arj1 wrote:
VERY short-term forecast (windy.com for right now) was not particularly precise.
Cloud bases are all incorrect, quite often some areas show “no data”, grey colour.
All I’m trying to find is how do you find data for now and/or short-term forecast?
One of the disadvantages of windy in my opinion is that while the actual representation, etc. is great, documentation is extremely poor. I haven’t found yet where I can actually check when the model has been run that is currently presented. Flugwetter.de is much better with respect to that but lags in graphical presentation).
Therefore if I look into windy right now, for the weather in 30 min. I simply don’t know if what I see is really a “very short term forecast” or rather the result of a mid term forecast calculated yesterday. Do you.
Windy.com (and some other similar platforms) are great to get a general overview and a forecast for the route (including when you are likely to hit the front, etc.) but for actual weather and short term predictions at a specific airport, METAR/TAF is the suitable product.
Apart from the windy community, is there actually and documentation? So far I have not found any.
Malibuflyer wrote:
I haven’t found yet where I can actually check when the model has been run that is currently presented.
There is an “Info” button just above the list of models. (Small I). Before it was the “clock symbol” in the same position. Click onto that and you get the information what model run is shown and when it was last updated. Generally I understand that it is always the last available model. But I totally agree, they should display this information somewhere around the model bar.
Malibuflyer wrote:
for actual weather and short term predictions at a specific airport, METAR/TAF is the suitable product.
Windy does supply METAR data as well as TAF and some other stuff using the airplane symbol.
At work, we use a much more elaborate platform but I have to admit that Windy comes very close to a great meteorological workstation when I don’t have access to our professional tools. However, what it lacks by its very nature is teaching people what they are actually watching and how to interpret data. If you use this kind of layers, dozens of models and other stuff, you need to learn about each of them to understand them.
Flugwetter has got text forecasts as well as interpreted products such as Gafor and the LLSWC’s e.t.c. which for people whose day job is not meteorology will give tailored and much more significant information. To use windy or similar platforms, the learning curve is steep. I am in weather now for 20 years and I don’t begin to claim that I understand all of the models and layers off hand.
It’s probably also fair to say that when the weather is ‘tricky’ a pilot will probably refer to more than one weather source, as they attempt to build a mental picture of what’s happening and how sure the forecasters/models are of their forecasts. (If all forecasts are similar, then there is a good chance that it’s right but if they vary quite a bit, then there is a lot of judgement being used).
Of course after a weather accident, particularly if the pilot doesn’t survive, the investigators might well find the log of some official website, but they can’t tell if that was only one of many sources that the pilot used. The pilot might well have consulted 2 or 3 other sources and concluded that the official one was pessimistic.
So they have to take official source logs with a fair degree of salt.
I found the representation of frontal systems very poor on Windy..Is there a way to get this visualized with a forecast time laps like the old charts?
Ibra wrote:
What do you mean by legal?
I was just meaning that, in case you crash and bad weather is suspected, it’s a good way for the investigators to verify that you actually received weather information.
Legal was a bit strong as a term, but some of my instructors did tell me that even if you have your own mean of getting a good weather briefing, have just a look on aeroweb with your own login. I have to admit it’s very french, as well as the fact that it looks like another FI legend…
