Wind speed definition/ missing info HURRICANE , CYCLONE
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Very basic important info is missing from the windy app. "Wind speed" is shown in forecasts by ECMWF, GFS and ICON, but there is NO clarification of what time average is displayed by each model. Searching the Internet gives no clear answer. All the following time periods are used in various countries:
10 minute averages
2 minute averages
1 minutes averages.The above makes a big difference, since the averages can lead to different danger for the exact same storm and location.
The wind gust definition is also not clear, except that one can assume that its the highest instantaneous wind speed?
Can the developers please clarify what time period averages are used for each model make sure to update it if there is every any change?
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@M-Magimu said in Wind speed definition/ missing info HURRICANE , CYCLONE:
there is NO clarification of what time average is displayed by each model. Searching the Internet gives no clear answer.
Yes, the wind parameter that is displayed in Windy by the Wind layer, is not defined by the ECMWF, the NOAA or the DWD… over a specific period of time.
So Windy developers can’t bring you more information about it.
However the weather models are “calibrated” over wind observations which are averaged on 10 minutes or 2 minutes. (There is not a big discrepancy between the speeds observed over 10 and 2 minutes). So you can compared the Wind forecasts in Windy with the 10-minutes wind at weather stations.
Concerning the 1-minutes winds they are only considered in the Saffir-Simpson scale. And there are only very specialised hurricane models that express the sustained winds over 1 minute. WMO says that 1-minute wind observations are 15% higher than the 10-minute ones.
As you refer to Hurricanes or Tropical cyclones, it is important to know that categories are defined according different wind scales in the different TC basins:
https://www.typhooncommittee.org/tropical-cyclone-classification/
https://en.m.wikipedia.org/wiki/Tropical_cyclone_scalesFor the wind gusts the WMO specify them as equal or less than 3 seconds.
