Forecast accuracy improvement

Software WxSim
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1

Part of this topic has already been discussed in another thread but I’d like to ask further questions.
I set WXSIM to mix the GFS and ECMWF data in ratio 20:80, respectively. For what I understand, the Autolearn module applies corrections to GFS data only, or? Other words: does Autolearn help with as it should in case the ECMWF has major contribution to forecast output?
Secondly, I’ve read the thread where the most appropriate times to pull the data were mentioned. I found out the model times vary, e.g GFS from 00Z and ECMWF from 18Z. I assume this is reasonable or unavoidable?

In most cases, different model times are not so important. We are expecting a fast moving cold front now, however, and model outputs change quite significantly (00Z-06Z-12Z, etc.). I’d just like to know if there is a most optimum time window to grab data from same timing.

2

Timings are tricky if you’re using both GFS and ECMWF data. Very approximately the ECMWF data is available 2.5-3 hours after the GFS data. So if you wait until ECMWF is ready then the GFS data is already 3 hours old and if you run just after GFS is available then ECMWF is about 3 hours old. So it’s always a compromise.

I run every hour (apart from the 2 hours that WxSimate won’t grab new data) with WxSimate set to only download if there’s new data. That avoids excessive downloads, but means that I always run with the latest available GFS, ECMWF and local data.

You can see the data availability times here - WxSimate Data Availability Statistics

3

Thanks, Chris, I used that statistics table to adjust my timings. I avoid running the forecast too often not to overload your server. I think I have the option to download “only if new data exists” enabled. So I will consider running forecasts more often.

I hope Tom or others will comment the Autolearn vs ECMWF question.

4

I must go back to set up auto-learn. When I last looked it was just after I moved my station to a different house and I didn’t have enough data. I should have plenty of data now!

5

i think you will find that only wxsim is not able to run forecasts for 2 hours wxsimate will get the data over those 2 hours if times seiected

6

You’d have to use a separate scheduler to do that.

However, Tom said he didn’t want to run for those two hours because he can’t be 100% sure how things will work if some data is from before midnight and some after.