Much later…
The high school took their Davis system permanently off net a few months ago. I missed it and (after too much research) bought an Ecowitt WS90 HP2564, mostly similar to a Tempest. It is very expandable for those needing extra sensors. I cannot make any conclusion about build quality or reliability until there are a few years experience, but all the sensors seem to be very accurate when compared to the official BOM AWOS that is 5km away for barometric pressure and more PWS systems around than I expected – on Weather Underground, WOW, and the Ecowitt network.
→ excepting for the haptic rain sensor that is difficult to assess unless one has a conventional rainfall gauge or another PWS or few in the immediate surrounds for comparison and tweaking.
A similar Ecowitt to the WS90 HP2564 is the WS80 HP2553 with a mechanical rain sensor, but the mounting style did not suit. There are also console-less variations of each.
Some observations about the PWS community rather than observations about weather include
- most PWS operators seem to plug and play rather than trying to calibrate
- some who make the effort to calibrate get absolute and relative pressure reversed
- many seem installed in sub-optimal residential locations so affected in one or more ways by shading, trees, buildings, and concrete
The WS90 is a Shenzen Fine Offset ‘clone’. A good but long read about Fine Offset clones is here.
A good index on the WXForum is here. Note there are numerous manufacturers with their own technology, so search them, there.
Davis is usually regarded as the top of the heap but Ecowitt and others provide more bang for the dollar, and many comments indicate they are as accurate as a Davis for 1/3 the price although probably not as long lasting.
Edit: I should flag that along with calibration many are prone to reset the daily data at midnight, and that is the usual default. Many national weather services do midnight however the BOM and our local river monitoring stations start and end their days at 0900 because dating back far enough observations were all manual, done by citizens who were often not inclined to wake at midnight to go out and about their properties to record measurements, but were quite happy to oblige mid-morning. How the other services got midnight readings or when they changed to the midnight reference or how they handle time-discrepancies I do not know. It could have been related to more ‘sophisticated’ equipment that had mechanically displayed high-low and time readings?
It appears only a small handful of my local PWS use 0900 with most using midnight, making for differences in the daily tallies from each ‘set’ of PWS as well as to the BOM or river station reference.
Why doesn’t the BOM change to midnight? Because it would invalidate the entire record prior to the date of change - and they are not inclined to suffer that for historical and research purposes.
