CHOICE membership

Home weather stations

weather

#21

Clearly I should never have made a suggestion of a solution that worked for me without ensuring that it worked for all systems in all circumstances. Mea culpa, mea maxima culpa.


#22

If I’m honest Sync, at 52 and 105kgs its a miracle I didn’t slide off our roof and into the neighbour’s laundry when I put it up! :stuck_out_tongue_winking_eye: Not racing to get back up…
Unless I get a mast to clear the peak of our roof it is kind of pointless anyway, and if you watch how those little wind vanes dance about in a decent breeze (1.2kms from Indian Ocean/Fremantle doctor) I really only got it for the other features. Temperature is affected by the tin roof, considerably in the mornings in summer.
Its a fun and interesting gadget (nearly 900mm of rain here since March!) But I think not to be taken too seriously.
In summer I can check internal house temp and turn the air con on before I get home if it is too hot, worth it just for that. :ok_hand:


#23

Out of sequential context, but

:roll_eyes:


#24

My dad and I have thought about purchasing one of these, so maybe not so niche? The weather forecast for our small town is taken from a weather station quite a distance away, with different local conditions, so we have been curious to know what is going on here.

We plan to purchase from Instrument Choice. Haven’t purchased from them before, but have made enquiries a couple of times and gotten helpful replies.

www.instrumentchoice.com.au/instrument-choice/weather-stations/home-weather-stations


#25

FWIW (over simplified, broadening the topic, and topically treated but might be interesting) forecasts as compared to local observations are derived from land based automated weather stations, satellite and radar data, and aircraft automatic data reporting as well as certain manual readings reported by citizens. Data is collected continuously 24 x 7 through national and international networks. Every morning the weather maps from the top national weather services (including the BOM) are compared to see which is most accurate in our Australian region; the data that fed into that map is incorporated in the BOM forecasts.

If not familiar, you also might enjoy the BOM’s Meteye. It takes a bit of fiddling to be able see all of its capabilities but you can drill down to a very small area and a fairly short time interval. It is driven by data in the BOM’s digital databases and is usually quite accurate.

Since this thread is about home weather stations another source is at http://bom-wow.metoffice.gov.uk/. There are other collections of amateur weather stations reporting as well as competing for-profit private weather services, many if not that derive their data from their respective national weather services such as the BOM.


#26

It seems to me that most sales in Australia are from ebay. That would make controlling what’s marketed difficult.

From what I’ve seen, most of the models available are made for the Northern hemisphere. I lucked onto information about needing to be able to adjust for the southern hemisphere, but it was pure luck.

My unit assumes that the WiFi is on 24 hours per day, 7 days a week. My WiFi is off more than it’s on - sometimes for weeks at a time.

The reliance on “the cloud” (being online all the time) completely floored me. I presume there’s some financial incentive to the manufacturers. All that information is probably valuable to the sites. There just isn’t any other rational reason that I can see.

Manufacturers are secretive about how signals from the outdoor units are encoded. I’ve read that Accurite (I think it was) will sometimes provide information, on condition that the recipient signs an NDA. That makes logging the data at home very difficult. Not that it’s stopped a great many attempts. :wink: The existence of a (now defunct) semi-commercial implementation does indicate that there’s a market for data loggers, though possibly not a commercially viable one.

It looks like there’s more interest than I’d anticipated. It’s a complex field, but the number of manufacturers is limited, so a review is feasible. I’d thought that Choice might be able to partner with overseas consumer groups, but being in the southern hemisphere seems to pose problems that northern hemisphere reviews wouldn’t address.

Hadn’t heard of them. Thanks for the pointer.


#27

My hope is that something will come along with integration to the home automation system, so logging energy, weather, and internal air conditions. So I’m guessing z-wave or zigbee. There are a few on the edge, but targeting wind & rain detection for automating awnings etc. I don’t want dozens of hubs each doing their own thing. There also seems lots of little DIY related to arduino etc (check mysensors.org). That’s not the level I want to go to. IoT though I think is where I’d like the my weather station to be.


#28

I can’t seen why there would need to be a fix for southern hemisphere wind direction. The US use the originating direction as the source for the wind direction, the same as Australia.

If the wind vane is oriented so that it its internal compass is orientated to the north (calibrated to magnetic north), then it should work no differently in Australia to the USA…east is still to the right 90° of north, west is to the 90° left of north with south opposite direction 180° of north. If there was a difference, a GPS bought in Australia would not work in the US and visa versa. This is not the case.

The only difference may be the anemometer measurement as the US will be imperical is most cases, while Australia is metric. If it measures in knots, the US knots are the same as Australian knots.


#29

Thank you, I’ll pass that on to my dad. I am sure he will be interested if he hasn’t already tried Meteye.

May I pick your brain on this topic? Can a home weather station tell you whether there was a frost overnight, or could it just tell you what the minimum temperature was?


#30

Nah, they face it South, not North. As @syncretic suggested I could easily face it South. Worst case scenario the batteries run out sooner, but as I look at it I always saw weather maps as where the wind is from, not to.
@blank - If you look at a site like Windy.com I’m not sure any of us need a weather station! Zoom that in to where ever you are.
But I wanted one, for the others thinking about it, I don’t regret getting it. I’d prefer that I could easily look it up online anytime, but you get what you pay for. If/when this one claps out I will get another, and maybe move up a class…


#31

Here is a little humour (please accept this in the Dad Joke vein of said humour). I trust my weather station for it’s technical simplicity, it is a largish gumnut suspended on a string. If it is wet it has been raining or the sprinkler was positioned in the wrong place, if it is moving there is wind or an earth tremor, if it has ice on it the weather has been very cold and moist (or it was very cold and the sprinkler was still in the wrong position). If it is dry there has been no rain and if it is hot and dry there is a very good chance the sun is shining and it is hot. Sorry for any pain felt while reading the previous.

Now to the serious part, most household weather stations are not sophisticated enough to detect the formation of ice/frost in a particular area. As an example frost could occur on one side of a building but not on the other due to a number of factors including air currents, and radiant heat and how would a weather station detect that mounted on a roof or on the side the frost didn’t form on. What you could surmise from temp and moisture content is the possibility of frost, but it is probably more likely you would see the result of frost on the foliage in the frost affected area/s. I am not sure how frost is detected by the Met Departments but radar might play a part in it and it may also involve affected people/areas reporting the occurence?


#32

caveat: I might be a bit out of date and would be happy to have anyone correct or augment the following.

First what is frost and why/how does it form

http://www.bom.gov.au/climate/map/frost/what-is-frost.shtml

Correct, noting frost warning systems featured in some products are exactly that, warning systems so fruit can be covered, etc. Warning systems can report when the temperature is within a range conducive to frost forming, but as you may have read from the link, it is not that simple to accurately predict frost. First, a user manual for an automated weather service quality system might be interesting to illustrate how complex simple measurements can be. Wikipedia has a summary of what automated weather stations can report.

While an amateur system can be had in the $100s to $1,000s of dollars, a weather service/aviation quality system will be in the multiple $100,000s and require regular maintenance and calibration.

A bottom line is automatic systems cannot differentiate between frost and dew because both can occur under similar temperature ranges and the conditions conducive to frost are simplistically those conducive to dew augmented by clear skies. While a met service/aviation quality automated system can be equipped to report visibility (eg at airports) and cloud ceilings it cannot report the breadth of cloud cover and other sensory systems (radar, satellite, infrared data) are brought into the equation.

As @grahroll surmised systems can predict conditions for frost but humans record actual frost.

Here is a link to my local high school’s weather system. It is a Davis system representative of a ‘better’ amateur product. The software is old, inflexible and the high school is not interested in spending the many dollars asked to upgrade it. One of the limitations is local daylight saving times cannot be adjusted so the local reporting times are off by an hour for weeks each year. Another aspect is that whenever there is a local power glitch the communications between the station and server go down, requiring manual intervention.

I have beaten this one into the ground but hope I have added insight to the question where @grahroll provided the working answer in a single sentence.


#33

Absolutely 100% totally correct and true.
I think the issue is if your weather station comes with a built in solar panel. For the USA the panel will be mounted Trump style to always look to the Deep South for inspiration and sunlight.

This would result in the panel facing Antarctica in Australia. There are some prior observations re this effect. So the real problem is not the weather vane pointing the wrong way. It’s the solar panel, which if it were to lay flat on top would be a universal model. Most of the USA other than Hawaii is so far from the equator flat laid solar panels don’t work all that well. Although there are some who still believe the earth is flat science wins on this one.

So some just install the station around the other way with north painting to the South Pole. I guess you could buy a stand alone solar panel and wire it in place of the built in.


#34

@mark_m, pure gold :slight_smile:


#35

Reading the manual for my hardware might help you. For wind direction calibration, see page 54.


#36

A fixed solar panel is a bit of an issue…the systems I have used in the past like Envirodata don’t have fixed solar panels and the panels can be located in any direction on or immediately adjacent to the sensors/logger.

I suppose this is something to watch when buying online as a fix panel may only set for northern hemisphere sun track (might be worth checking before buying and seeing if there is a southern hemisphere fixed panel version). In the northern hemisphere, the sun generally tracks is in the southern sky…while in the southern hemisphere, it is in the northern sky (unless one is between the Tropic of Capricorn or Cancer, where the sun may track slightly into the other half of the sky in the summer period).

If one has bought a northern hemisphere solar panel set weather station in Australia, or from an online retailer claiming that it is suitable for Australian conditions, one could request a refund under the Australian Consumer Law as it is not fit for purpose (in Australia).


#37

Apart from a few months around the summer solstice, when it shines from the south :sun_with_face: Being north of the Tropic of Capricorn will do that. :grinning:

I’ve purchased a few instruments of various types from them over the past few years and found them to be great- stocking only good quality products, with fast delivery and reasonable pricing.

It can certainly tell you the minimum air temperature (the station should be mounted using the correct materials at the correct height in a suitable location away from structures and shading trees. I’ve seen frost on the grass with minima as high as 5C, as the grass temp is generally a few degrees lower than the air temp at 1.5metres above ground. However, that isn’t always the case, as it can get significantly lower and not be a frost if there is a wind blowing, reducing the stratification, and therefore the temperature gradient near the ground.
Local topography will also have a significant influence on the temperature minima, with cold rivers of air flowing down gullies and valleys overnight, often keeping locally more elevated land a few degrees warmer.


#38

You got me, but my defence is

that I thought handled it, but apparently not. I yield the point. :frowning:


#39

Strange things happen if you go north of the goat line!


#40

One that’s easily addressed in software. The fact that a company can’t be bothered says something about their attitude. That something doesn’t motivate me to buy their products.

Meanwhile, the saga continues.