snow or not snow?

[emre33tr]

whether Jon or not, snow is what makes earth beautiful.

[emre33tr]

How accurate is your snow forecast? yesterday there was no snow in 10 day forecast. 2 days ago there was snow in the same place. today it is snow again. im really confused with the stats.

[Gkikas LGPZ]

@emre33tr
Forecast accuracy decreases at the end of 10 days forecast period.
3 or 5 days forecast has high accuracy.

You say:
A. "yesterday there was no snow in 10 day forecast."
So, model forecasts no snow for the period 27 Dec~5 Jan.

B. "2 days ago there was snow in the same place."
So, model forecasted snow for the period 25 Dec~3 Jan.
but only for the first 2 days (25,26 Dec) of the 10 days forecast period.

C. "today it is snow again."
So, there is snow forecast for the last days of the 10 days period (5,6 Jan).

For more details, start-stop time of snowfall,
consult this map
https://www.windy.com/-Rain-thunder-rain?rain,2019-01-05-18,40.145,43.638,5,i:pressure

[emre33tr]

thank you for the explanation @Gkikas-LGPZ
:)

[emre33tr]

yet it is still impossible to have that much "snow depth" in my area. 3 day and 5 day model is more realistic. 10 day modelling is just wishes :)

[idefix37]

@emre33tr

I think the snow depth is theoretical. After a consequent fall, the snow settles under its own weight and with the variations of temperature in the snow layer...
I don’t think the weather model takes into account the transformation and contraction of the snow layer.
Then a 10-days forecast for snow is even less reliable than a 10-days forecast of rain because 1 or 2° of temperature error can make a big difference.

[emre33tr]

@idefix37 i agree. tnx 4 the explanation.

[Gkikas LGPZ]

@idefix37
Do you know which parameter is used by windy?

Snow depth water equivalent
https://confluence.ecmwf.int/display/TIGGE/Snow+depth+water+equivalent

or

Snow fall water equivalent
https://confluence.ecmwf.int/display/TIGGE/Snow+fall+water+equivalent

P.S. Have a Happy New Year's Day!

[idefix37]

@gkikas-lgpz
Thanks for the info.
Happy New Year to you !!

[emre33tr]

happy new year all.

[Gkikas LGPZ]

@emre33tr
with a lot of snow in our area!

[emre33tr]

@gkikas-lgpz hope it proves to be correct. when i search by snow depth from the right bar this map comes. but when i click on the city name another page is coming from the bottom. and that page is showing more rain than snow. there is a mistake with the map i think. thank you for the info :)

[Gkikas LGPZ]

@emre33tr
Snow is expected in Istanbul for the next few hours.
Temperature -6C at the level of 850 hPa (1500m) is critical for snow forecast even at sea level.