Description of weather overlays
TZ Administrator last edited by
@IgorXXXmirror Hi, 100m layer is above model terrain. Unfortunatelly it is very coarse terrain with 9km horizontal resolution.
IgorXXXmirror last edited by
Rani | Premium last edited by
When using wave overlay, I see a color key indicating wave height and also boxes with values in them with either- or~ before the value. These numbers never match the color key .
Atalantia last edited by
What means the 330 before 64km/h?
wind direction 330 degrees (coming from NorthWest)
jmds last edited by
@ivo said in Description of weather overlays:
I cannot see RAIN RATE in the settings ....
alecloudenback | Premium last edited by
Is there an overview of the meteograms that Windy displays for the forecasts? I am not sure of what some of the background colors and charts mean.
sonnigekerstin | Premium last edited by
@alecloudenback Me neither. I was searching for a manual to find out about the meaning of the different colors,graphs,pictograms etc....
@tz What height does surface refer to? There would technically be no wind at the surface, so it must be some standard height above the ground (whatever the common reading instrument height is). What is that height? (i.e. 2m, 10m, 20m?). I'd like to use the data to estimate wind shear at a given location and using surface (0m) is not valid.
Surface wind refers to 10m above model's surface.
Surface temperature refers to 2m.
For ECMWF datasets, see https://www.ecmwf.int/en/forecasts/datasets/set-i
For ICON, see chapter 6 (Global output fields) in
"Database Reference Manual for ICON"
.... or scroll on top of this page
@ivo From Leilani Estates Big Island Hawaii: what is the source of SO2 data? Satellite only? Any way to include data from ground monitors such as: http://weather.hawaii.edu/vmap/hysplit/ ?
For the source of SO2 data ....click ...
IgorXXXmirror last edited by
What does it mean in lightning l / km ^ 2?
lightnings per square kilometer.
TomSlavkovsky API developers last edited by
@Gkikas-LGPZ @IgorXXXmirror There is a mistake pointed out by ECMWF - it should be flash/km2/day.
If the unit is flash/km2/day, why does the map changes every 3 hours? Is it a sliding average over 24 hours? Looking to the way how thunderstorms move on the map every 3 hours, it seems surprising
Gkikas LGPZ Moderator last edited by Gkikas LGPZ
I think windy uses "Averaged total lightning flash density in the last 3 hours (litota3)"
with unit conversions.
P.S. as the model's grid is 9x9 km, I propose to keep the original ECMWF density
(units of flashes per 100 sq. km per hour).
Windy converted values down to 1 sq. km,
but this is a "very small" area for lightning forecast
and maybe it is prone to larger errors.
Thanks for this information. However, I still can’t understand how the thunderstorm maps can change every 3 hours step if the parameter used is « per day » (which is the case of the 4 parameters described in the ECMWF document). These parameters are probably useful for statistical comparisons, but not for forecast.
And it’s what is explained in this document :
So the ECMWF provide probably data to Windy in [ flashes / 100km2 / hour].... to be confirmed