Description of weather overlays

Peter Bayfield

What does the blue arrow next to my location indicate. It revolves to different direction as I rotate my smartphone.

idefix37

@Peter-Bayfield
This blue arrow indicates nothing. Just forget it.

lotayah446

@gjwolfswinkel said in Description of weather overlays:

The freezing altitude layer, how does that work? I am often looking at ski weather and on those sites, the current freezing altitude (frostgrenze in German, vorstgrens in Dutch) is at around 3800 meters. Yet the 'freezing level' layer shows values of 2500 to even 1900 meters for those locations, even though the current temperatures there are much higher.
Am I misinterpreting what the freezing altitude layer actually is or does? Or is the data faulty?

The freezing altitude layer or the freezing level is a meteorological term that refers to the altitude in the atmosphere where the temperature is at or below freezing (0 degrees Celsius or 32 degrees Fahrenheit). The altitude at which the freezing level occurs can vary depending on the temperature profile of the atmosphere, and it can be affected by factors such as atmospheric pressure, humidity, and wind.

In the context of skiing weather reports, the freezing level or freezing altitude is an important parameter to consider because it determines whether precipitation will fall as snow or rain at different altitudes. If the freezing level is high, then precipitation will fall as rain at lower altitudes, which can result in unfavorable ski conditions. On the other hand, if the freezing level is low, then precipitation will fall as snow at lower altitudes, which is generally more desirable for skiing.

asif ali 10

How does weather overlay work?

As a weather overlay, the navigation chart, fishing chart, and perspective 3D view can all be layered on top of each other to display information related to weather and weather conditions. Depending on the chart, both the navigation chart and the fishing chart can be displayed with weather radar, cloud top heights, lightning, weather buoys, county warnings, and hurricane warnings.

emilyyyZzz

Is there any description or any more information on the Satellite overlay with BLUE, VIS, and IR lenses? Apologies if already asked.

mrp 2

You make it rain in my place!! And there is terrible sun and clear sun

idefix37

@mrp-2

Windy does not make rain !
The layer that you show is the forecast of lightning per sq .km (l/km2). It just predict a possibility of thunderstorms.

Gkikas LGPZ

@asifnaveed8527
For history of numerical weather prediction
https://en.wikipedia.org/wiki/History_of_numerical_weather_prediction

For the future ...
https://www.technologyreview.com/2023/07/11/1076067/weather-forecasting-is-having-an-ai-moment/

Trust Haven Solution

Hey, I just wanted to say a big thank you! Your content has been incredibly helpful and exactly what I needed. I really appreciate the valuable information.

Handrickson Justin

Thanks for the detailed explanation of the various overlays and their sources on Windy! It's great to have a comprehensive understanding of each feature and its functionalities. Keep up the good work!

Tiago Castelani

How get any second is used to wind gust.

I made this question, because if I had that define the máximum speed occoured in one edifications that has damage with the wind, I need get the wind speed to wind gust with 3-s (seconds).

Can explain for me?

idefix37

@Tiago-Castelani
Your question is not clear at all.
You’d better ask it in your native language, we will translate it.
Find out here how the ECMWF consider this parameter:
https://codes.ecmwf.int/grib/param-db/?id=228029

c4551u5

I'm confused by New snow and Snow depth - it says that snow depth in 24h will increase more than the amount of new snow in the same period. How is that possible? Here are screenshots - snow depth goes from 3.9cm to 12.2cm in 24h but new snow in the same period is 4.8cm.

idefix37

@c4551u5
See information about Snow depth forecast by ECMWF:
https://charts.ecmwf.int/products/medium-snow-sic?base_time=202311250000&projection=opencharts_central_europe&valid_time=20231125000
As explained by ECMWF, below 10 cm there is some inaccuracy.
I agree it is weird as the density is increased after the snowfall. It should decrease.
It shows it is not arithmetic :)

helloworld1

The freezing altitude layer, how does that work? I am often looking at ski weather and on those sites, the current freezing altitude (frostgrenze in German, vorstgrens in Dutch) is at around 2000 meters. Yet the 'freezing level' layer shows values of 2500 to even 1900 meters for those locations, even though the current temperatures there are much higher.

Am I misinterpreting what the freezing altitude layer actually is or does? Or is the data faulty?

Thanks!

idefix37

@helloworld1

Here is what the ECMWF says about this parameter:

“ This chart [of the freezing level] represents the height of the air temperature 0°C isotherm.
The chart shows the highest altitude where the temperature passes from positive to negative values with increasing height. It does not show zero degree levels in an inversion where temperatures pass from negative to positive values with increasing height.
The altitude of the 0°C isotherm allows some estimation of the level where snow melts to rain. It is also important in aviation, especially for smaller aircraft, as accumulation of ice on the airframe can occur at altitudes near to this level”.

Furthermore, this temperature is that of the air mass in free atmosphere but not at ground level. Therefore, there may be a certain deviation from the temperature observed locally, particularly in case of temperature inversion.

Mary_G

Hello! I couldn’t find a description, where I can read about the Thunderstorm layer from ECMWF weather model, thanks!

idefix37

@Mary_G
You have it in your screenshot.
This layer represents the forecast by the ECMWF model of the number of lightning strikes per sq.kilometer for a day.
I/km2 means lightning per sq.kilometer.
See more information:
https://codes.ecmwf.int/grib/param-db/?id=228057

Mary_G

@idefix37 thank you! on my screenshot - there is description: "number in one day", it is a little bit confusing

Thunderstorms - defined as number of lighting flashes in the area of one square kilometer, in one day.

but it clears now, thanks - Note that this parameter has units of flashes per square kilometre per day. Conversion of this parameter to units of flashes per 100 square kilometres per hour can give values that are easier to interpret.

111 000

Под каждым слоем как в цивилизованном мире нету краткого описания в контекстных меню?)