Description of weather overlays

idefix37

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?)

faiqarani

Here’s a concise, human-readable summary of the features:

Radar, Lightning: Displays weather radar and real-time lightning strikes, using different data sources but sharing a timeline for animated playback.

Wind: Shows average wind speed 10 meters above ground, with gusts computed for the last 3 hours and a 10-day accumulation map for maximum wind intensity.

Rain, Thunder: Displays rain/snow accumulation for the last 3 hours with a lightning density forecast.

Rain/Snow Accumulation: Forecasts total rain or snow accumulation over the next hours or days.

Snow Depth: Predicts snow depth, influenced by various factors like terrain and urban areas.

Precipitation Type: Indicates types of precipitation (rain, snow, sleet, etc.).

Thunderstorms: Counts lightning flashes per square kilometer per day.

Temperature: Shows temperature 2 meters above ground.

Dew Point: Temperature at which air moisture forms dew.

Humidity: Relative humidity 2 meters above ground.

Freezing Altitude: Altitude where temperature hits 0°C.

Wet Bulb Temperature: Lowest temperature via evaporative cooling, critical at 35°C.

Solar Power: Amount of solar radiation reaching the Earth's surface.

UV Index: Measures the sunburn-producing UV radiation strength.

Clouds: Shows cloud cover at different altitudes and their rain/snow accumulation.

Fog: Displays fog conditions, influenced by local factors.

Visibility: Measures how far objects or light can be clearly seen.

CAPE Index: Indicates potential energy for storm formation.

Thermals: Shows thermal activity and cumulus cloud occurrence.

Waves: Significant wave height and period, combining swell and wind waves.

Sea Temperature: Estimates sea surface temperature.

Currents: Displays surface sea currents.

Tidal Currents: Tidal movements influenced by Earth, sun, and moon.

CO Concentration: Carbon monoxide levels in the air.

Dust Mass: Concentration of dust particles in the air.

SO2 Mass: Sulfur dioxide concentration, often from volcanic activity or fossil fuels.

Ozone Layer: Total column of ozone, affecting UV radiation.

Soil Moisture: Amount of water available to plants in the soil.

Moisture Anomaly: Deviation of soil moisture from average levels.

Drought Intensity: Compares current soil water with historical levels for drought assessment.

Pressure: Atmospheric pressure at sea level.

Weather Warnings: Alerts from national weather agencies.

pusat monitoring

Hi Moderator, i wanna ask you something.. can i get the raw data of precipitation prediction or nc file?

b store

s there a description of Wind Accumulation? Seems like it would follow this description from above

"Rain accumulation: Total rain accumulation in the next hours or days."

But I am seeing it change for the path of Hurricane Florence southward along the South Carolina and Georgia coasts, which matches the spaghetti model's adjustments I've seen as well.
Is Wind Accumulation an indicating factor in those models I guess? Also is there a plan to add those as a layer to the Windy interface?

idefix37

@b-store

Also is there a plan to add those as a layer to the Windy interface?

Wind accumulation is already available as a layer in Windy.

Layer w/customized colors

Wind accumulation is the max gusts field during a period of time (days / hours) as predicted by a weather model.

Frohe

Hola! Muchas gracias por este Post!
Aunque lo he leído todo, no acabo de encontrar la respuesta que busco.
No acabo de entender la capa del radar.
Hay veces que veo claramente como se emite o recibe las lecturas por las líneas rectas que salen desde la situación de un radar en cuestión dentro de su alcance, pero no siempre se ven estas lineas y no desde todos los radares, o unos días sí y otros no... ¿Hay alguna razón para ello? Si siempre están en funcionamiento los radares, al atravesar las ondas las partículas de agua de la atmósfera en ese espacio de lectura, ¿no deberían producirse siempre estas líneas? ¿Por qué unas veces aparecen y otras no?

idefix37

@Frohe
Hello, these long beams on the Radar layer are not normal. They are anomalies due to interference by WiFi sources encroaching on the radar frequencies due to a bad setting.
Same as
https://community.windy.com/topic/36512/strahler-um-posen-und-karlskrona-beim-wetterradar