NAM model

[ahorvath1]

Curious as to why your NAM model forecast is so different from the one shown for my area on SPOT. I am at Gun Lake in the South Chilcotin mtn’s by Goldbridge BC in Canada 50.86917 Lat, -122.87671 Long

[Suty]

@ahorvath1 Could you please provide link, so we can compare the situation?

[ahorvath1]

@Suty The link is spotwx.com
I have noticed that quite frequently when it is raining at my location, the NAM model on Spot has shown it in the forecast, but the NAM model on Windy has not called for rainfall.

[Filip_K]

Hi @ahorvath1,
looks like spotwx.com uses different NAM model with 12km resolution:

Windy uses NAM with 5km resolution:

Both of them are listed here.

[ahorvath1]

Strange, I would have thought that the 5 K resolution would be more accurate than the 12k rather than less accurate.

[Filip_K]

@ahorvath1
Well, yes and no. Since lower resolution model is more smoothed out, it is more likely to predict rain in Your exact spot, if the rain is "somewhere" nearby.

It is known as double penalty issue and You can read a bit more about it here.

[ahorvath1]

@Filip_K Thanks for the explanation