Meteoblue forecast differences between Meteoblue and Windy

btschumy

I notice that the Meteoblue point forecast in Windy always seems to differ significantly from the forecast on Meteoblue's site. Just curious as to why that is.

There seem to be two possibilities:

The updates times are different. I seem to be unable to find the last update time on the MB page. However, for the Windy MB forecast it currently says this.

I am at UTC-7, so if I'm not making a mistake, this should be 8:36 AM local time. It is currently 8:56 AM local time so that is pretty recent. However, I don't understand why the Reference time is two days earlier without a time associated with it. If that is correct then that could explain the discrepancy.

The other possibility is that Windy is using a different Meteoblue model than used on the MB site. MB says they use Meteoblue AI. Windy also says they use Meteoblue AI (see last image above). So unless some of this is wrong, it doesn't seem like the models are different.

Like many folks have commented on, MB is the most accurate temperature forecast for my area and I prefer it. It would just be nice to know why Windy's MB forecast differs.

ETA: I would also like to clarify that I am using the same location in both cases, down to within 50 meters or so. So I don't think different locations could be the reason.

Thanks.

idefix37

@btschumy
I did the same comparison and I only see a difference of 1°C, which may not be significant. It could be due to rounding as temperature is usually provided in Kelvin by weather models.

At same location for next Sunday, I see the same discrepancy i.e 1°C max, sometimes.

btschumy

@idefix37 Thanks for looking. It is often much more than 1º. I have seen 4-5º differences at times. Definitely not rounding. Something is going on.

If I look now they seem pretty close for the next couple of hours and then diverge again.

btschumy

Here is another example from this morning:

Note that the high temperature for the day is a 3º difference.

Again the Reference time is from 2 days ago. The Update time is 9:47 PM from last night.

I would appreciate someone from Windy explaining this. It almost seems like you use a model that was initialized 2 days ago. If so, that could explain the discrepancies. Maybe that is part of the agreement for gaining access to the MB forecast – you have to use one that is 2 days old?