The temperature of the Mediterranean sea is quite high this year. In some ares, temperature at the surface is around 28°C. This is of course due to the hot spring and summer.

This situation is not without consequences :

1. a medicane was formed close to the Libyan coasts and hit last Friday Greece creating a lot of damages because of the wind and rain

2. yesterday, in the South of France, because (but not only !) of the intrusion of very warm and humid air from the sea, combined of course with other factors (instability, anomaly in altitude, wind shear), it created a multi cellular thunderstorm which was stationary : each new convective cell (this is why it is a multicellular system) is created in the exact opposite way of the move of the system in altitude because of the wind shear. This creates therefore a stationary thunderstorm which is terrible in terms of rain accumulation because you can get huge quantities of water at the same place during 24h or even more.
   This thunderstorm created floating and a lot of damages in France (more than 600mm of rain in 24h)

Unfortunately, other episodes like the ones mentioned above could happen in the coming weeks,...

@Sybiljamie

If you look your data for Saturday the 13th of August, you see 0.4mm at 5.00AM. This is the total of rain accumulation between 2.00AM and 5.00AM. Then you see 0.9mm at 8.00AM. This is the total of rain between 5.00AM and 8.00AM.

If you go for Windy Premium, by splitting from 3h forecast to 1h forecast, you will see how the rain fall is spread by 1h in place of seeing the accumulation over 3h : for instance, you could have 0.2mm at 4.00AM and 0.2mm at 5.00AM as a potential example

@CR
No, in general with Windy, you cannot combine different maps, except pressure, geopotential, temperature and isotherm that can be display on any other maps.

@nwindy
Yes, the way the ensemble model calculates the probability is as you explain : for instance for the rain, each dot of the 21 dots can give a different level of rain (1mm, 4mm, 10mm,...). Based on that set of different levels of rain, the model can calculate several probabilistic values such as the average, variance,... This will allow you to quantify the risk of rain

Now, if the model has to adopt the same approach for many other parameters, such as pressure, temperature,... And for each parameter do the 21 calculations (do not forget that each calculation is the equivalent of a single deterministic calculation), computional limitation will be the issue if the model keeps the same grid. To overcome this problem, grid is bigger, calculation of the 21 dots for the different parameters becomes ok but accuracy will decrease.

Computational calculation is key. In average, weather forecast improves by one day every 10 years thanks to the computer (super calculator) progress

@disaster999
I would like to add 2 comments :

1. as @idefix37 and I already highlighted couple of times, Windy doesn’t make any weather forecast model, Windy doesn’t do any calculations with the models, Windy only publishes the data coming from several models and present those data in a very nice and useful interface. Therefore, Windy has no responsibility regarding the accuracy of the data. Only the institutes making the models have this responsibility. Having said that, it is also the responsibility of the user to study the different models and determine which one is the most appropriated for the location and for what he or she is expectating as accuracy. It is also key not to mix the concept of a FORECAST and CURRENT weather. Do not look at models to check the CURRENT weather but check then weather stations or satellite images.
2. In general, severe and local phenomena are still difficult to be modelized by the current models. It is the case for instance for thunderstorms. The reason behind this issue has a name : convection. Convection unfortunately do break one fundamental assumption used by all models : hydrostatism. At synoptic level, atmosphere is stable and this is what hydrostatism is telling. Convection, locally, creates an air circulation starting from the bottom, from the ground or from the see, to the altitude. Therefore, atmosphere is not stable anymore and we are locally in a non hydrostatism assumption which is not yet well modelized by the models even if they did a lot of improvement, especially Arome. While it is easy to predict that a region will have all ingredients to get potentially a thunderstorm, it is very complicated for all models to be accurate enough to tell you the exact localisation of the thunderstorm, the exact timing and the exact intensity (wind speed, rainfall, hail,...). More severe phenomena, as hurricanes, have the same issue for more or less the same type of reason.

One of the typical feature of a medicane is the hot core which is much warmer than outside. It is very interesting and instructive to follow it at different levels. At the beginning, you could notice the difference at low levels, 850 hPa for instance but day after day, you can see the differences, in the core and outside, also at much higher levels. This is because in the development process of an hurricane, the system releases latent heat, among others because of the condensation of warm and humid air at higher and higher level. Here you can see it clearly on the follwing map at 600hPa : +2°C in the core, -2 or -3°C outside. Huge difference !

Very instructive to follow the development of this medicane

@psweetapple
As a Premium user you can get 1h forecast (you have to activate It in the meteogram) and soon 4 updates a day with ECMWF Model in place of 2 (already available on the desktop)

@ivo
I agree with you, IFS from ECMWF is probably the best model to predict all changes in the atmosphere at synoptic level. I will never prepare a forecast without checking it.
Having said that, there is still a weakness : convection, convective cells and thunderstorms in general. This is where a model like Arome is important to have with Windy because Arome has a certain superiority to predict such a event.

@Rovina
Confusion comes from the fact that each model is made by a company or an institute and each model has a specific name. Problem is that people use often the name of the institute in place of the name of the model :

Meteoblue makes a model called NEMS

ECMWF makes a model called IFS

The National Centers for Environmental Prediction (NCEP) produces a weather forecast model called GFS

German Weather Service and the Max Planck Institute for Meteorology work together to propose a model called ICON

@joelanier
Windy collects data from weather provider. They don’t do any calculation. They put in one place all data from IFS, GFS, etc... If there is somewhere an institute which can provide for free global front maps coming from their calculation, Windy could think to integrate potentially this map in their app,...

So far, front maps are available from a lot of weather national institutes, like IRM, MET, DWD, Meteo France,... They prepare them manually and then they propose an forecast of this map using models like DWD using ICON to forecast the front map evolution. Issue : starting point is done manually and it is a local front map, not global front map

For those who want to read info about the interest of blue channel in VIS : http://www.eumetrain.org/satmanu/Basic/RGB_Channels/print.htm#page_3.0.0

@Korina
I think it would be great if Windy could give a communication on this change, explaining the interest of this new blue channel

@przemo1986 said in New satellite view:

kiedy w aplikacji zostanie to zmienione ?

It is already the case and integrate with the desktop version. See the satellite view I attached in my inital message above

@petra-pik
@Korina

I have seen a change in the satellite views : it seems that infra view has been replaced by blue channel view. I guess it is still infra but with another treatment.

Could you please comment on this change ?

Thanks !

@newmoon22
Premium users get access to the 1h forecast in place of the 3h forecast and 4 updates/day in place of 2 for the IFS model from ECMWF. You won’t get access to more weather stations

@Joerg78
The model from ECMWF is called IFS. This model has 4 run per day: 0z, 6z, 12z and 18z. So far, Windy gave us access to only 2 run, 0z and 12z (the main run). Now, the Premium users have access to the other 2 run, 6z and 18z

@Bianki
No, the compare tool of the meteogram only uses the 3h forecast to compare the data from the different models.

The basic idea of this tool is to give you in a snapshot a quick and short overview of the forecast from the different models to appreciate and evaluate the consistency or not between the models. The objective is to understand if all models converge to the same general trend or not. You will lose this visibility, especially on a smartphone with a small screen, by doing it with the 1h forecast

@Falco
Yes, thêta e and even more interesting thêta’w are 2 very important potential temperatures used in meteo. The goal of Windy is to be an outdoor application oriented, not really to be a tool for meteorologists, although we have tonrecognize that a lot of them use Windy because the app is very nice and easy to use!

Having said that, we can debate about the limit : when data are outdoor oriented and when data are really dedicated for meteorologists only ?

I would love to see thêta’w at 850hPa in Windy as it is something I use extremely often and I have to go to another site ton get the info,... But it is maybe not enough outdoor oriented

One idea could be to integrate thêta’w in the sounding or in a SkewT type (emagram) of plugin

@joelanier
Windy collects data from weather provider. They don’t do any calculation. They put in one place all data from IFS, GFS, etc... If there is somewhere an institute which can provide for free global front maps coming from their calculation, Windy could think to integrate potentially this map in their app,...

So far, front maps are available from a lot of weather national institutes, like IRM, MET, DWD, Meteo France,... They prepare them manually and then they propose an forecast of this map using models like DWD using ICON to forecast the front map evolution. Issue : starting point is done manually and it is a local front map, not global front map

@sailingcoco
Of course, you can set up weather alert. Look at this tutorial to learn what you can do and how to do it :
https://community.windy.com/topic/7797/windy-tutorial-weather-alerts?_=1601038567167