10 Min Peak Gust oddity

[Mapantz]

I happened to be looking at my website just as the strongest gust of the day occurred. It was 36mph, and just prior to that, the 10 Min Peak Gust was 34mph.

The 10 Min Peak Gust then changed to 36mph, then changed back to 34mph, then back to 36, then back to 34, then back to 36, before staying there. I've never seen that happen before!

I'll enable data logging, as it should start getting higher.

[Mapantz]

Now it's alternating between 30 and 35mph.

20230309-000941.zip

[Mapantz]

I left the weatherlink live app open and just had a 37mph gust. That showed on the app and stayed at 37mph. CMX was swapping between 36 and 37mph.

20230309-000941.zip

Just to confirm; It's doing it on the CMX dashboard as well, so it must be a little gremlin

[mcrossley]

In the last log I see that the "live" broadcast data is showing max gust in last 10 minutes is 37.00 mph, but the "current" data when querying the WLL is showing it as 36.00 mph.

It appears that the "current" data from the WLL is only updated once a minute, and so lags behind the live data.

If Davis confirm this and aren't going to change it, then I'll have to think about how to handle it.
If broadcast data is being received, then it should take precedence over the current data.

Tbh it's a bit disappointing that "current" API call returns some cached values for data rather than their current values as the query name suggests.

[Mapantz]

That's very strange!

If there's high winds here, I tend to leave my phone screen on while I'm working, so I can see the wind updates. The swapping of those values has never happened before, so have Davis changed something their end?

[mcrossley]

No changes, I believe it has always been that way. Apparently the current conditions is actually the last one minute data sent to wl.com not the actual current. Anyway, I'll add a workaround for this in the next build.

[Mapantz]

This issue started happening again earlier.

[The PIT]

How often do you log your data. I log mine every five minutes and the other day recorded an ten minute average of 40 mph which seemed wrong but checking the data for that time period showed it to be correct.

[Mapantz]

How often do you log your data. I log mine every five minutes and the other day recorded an ten minute average of 40 mph which seemed wrong but checking the data for that time period showed it to be correct.

This is a problem on Davis' side. I hadn't ever seen it before I made this thread.

As an example, If the 10 minute max gust shows 30mph, and I get a 32mph gust. The 10 minute max gust figure keeps flicking between 30 and 32mph.

Davis are caching values or something?! Like I said, during strong winds, I have the Davis app open on my phone so I can keep track, but I had never seen it before.

WeatherLink Live btw.

[The PIT]

I thought it was your web site that was reporting the data.

Still could be right though if you're getting gusts 32, 30,32, 30, 32 every minute as you move through the ten minute periods it would go back and forth.

[mcrossley]

Apparently the current conditions is actually the last one minute data sent to wl.com not the actual current. Anyway, I'll add a workaround for this in the next build.

[The PIT]

Being sad I've been sat watching the weatherlink app on my phone and it does what Mapantz says as does the wind direction and may do it several times within the minute. I don't think what Mike is proposing will make much difference.

So what I had was 25 mph as last ten minute high when another minute passed it went to 19 back to 25 then back to 19 I also noticed the wind direction of the max gust changing as well to different directions.

Okay I think it updates every 2.5 seconds so it's displaying correctly you just have to remember that the ten minute period isn't a set period as it moves on every two seconds so yes will can see things switch back and forth. The only time you wouldn't if there's a huge difference in wind speed. E.G a line squall that produced a freak 50 mph gust while the rest were just 25 mph. Eventually once the time period for 50mph has passed you would see a return to jumping that you see now.

[Mapantz]

Sorry Mark, I thought it had been fixed when I read this in the updates.txt:

- Davis WLL using "stale" current wind gust data

[mcrossley]

Ah, sorry, given the date of that comment I assumed the change hadn't made it into the current build.

When you next get this oscillating, could you switch on debug and data logging and post the MXdiags file please?

Also, I'd be interested to know, when you see this in the WL app, if you are using MPH: does the "wind speed" ever show a decimal number? (Other than zero that is!)

[The PIT]

Like I said I observed the same and there's nothing to fix. If gusts are roughly similar it will oscillate. Gust at 2.5secs 30 mph gust at 5secs 32 mph gust at 7.5secs 30 mph you would see 30 mph then 32 mph then 30mph which be shown in the weatherlink app and cumulus. Remember the ten minute window will be moving forward.

If you're looking at the ten minute gust in a set period then 32 mph would be shown.