Best settings for storm alert

Try 3.5 over 4hrs 

There's absolutely no blanket value.  You have to figure it out for where you live.  Where I live, we have radical changes on normal, sunny days due to airflows over the mountains with no discernible change in the weather.  For this, I've found incredible accuracy using larger change thresholds.  Where I used to live at the coast, smaller changes.

And yes, air pressure does change inside the car depending on how you're driving, a/c on off, windows open ir closed, interior volume, atmospheric pressure changes, etc.  More or less the pressure change is dampened

Also what is the watch set to auto/baro or altimeter biased? There are so many factors and without over complicating it. Start with larger ranges indeed. I usually leave mine off unless I'm out in mountain or in wilds as the storms alert can save a soaking or pop up a tarp and have some food and let it pass. 

U can also calibrate for you GPS location as if the watch is set to auto bit u haven't used GPS for a while the correct altitude may be incorrectly shown. Use it to assist you but don't let it distract you from your task

I was wondering about same thing (auto/baro/altimeter setting) - what settings do you use? The only usecase I have for strom alert is mountain hiking, to have another level of warning just in case (if I forget to read the weather or goof up some other way), however if I set the watch in baro mode the altimeter readings will suffer in acitivty?

As for correct setting - I start at a low setting and increase it each time I get a false positive. This is the easiest way for me when I'm travelling :) 

It's tricky being honest. If your mainly wanting to track height then that's easier but for me setting to auto when in mountains seems to work fine. Again I use as a guide as reading the cloud and wind in a local area. 

So as for the bias; if you set to altimeter the change in pressure will be attributed to height and baro is the opposite. Just tells the watch what's more important. When I'm home and not expecting changes in height I set to baro mode

Alpha Pews said:

When I'm home and not expecting changes in height I set to baro mode

Unless you want the watch to count the floors climbed during the day (if you have any at home).

So basically it’s really whatever i find useful in the environment i am in. If I’m in the woods, turn the barometer on to altitude based?

NoTrux said:

And yes, air pressure does change inside the car depending on how you're driving, a/c on off, windows open ir closed, interior volume, atmospheric pressure changes, etc.  More or less the pressure change is dampened

No it has nothing to do with that. Even with window open I got this warning, when driving to the supermarket. And yes it is uphill. I had exactly the same problem with my Casio Rangeman.

Two brands with significantly different measurement methods, you're having the same problem.

My suggestion is to read the manua9.