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Weather Related Organizations => PWSweather / AerisWeather / WeatherForYou => Topic started by: Plug Nickel on June 15, 2020, 02:30:44 PM
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Running into a strange problem.
I'm updating PWS weather with Virtual Weather Stations built in WeatherForYou / HamWeather updater.
My Virtual Weather Station software reports my barometric pressure as 30.08” and is reporting that value however PWS Weather shows it as 29.44”.
Even stranger, WeatherForYou shows it correct as 30.08”.
I thought WeatherForYou got its data from PWS Weather so how can they be different?
I've been sending emails to PWS Weather, but does anyone here have a clue?
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WeatherForYou only gets data from your station if you gave them permission to use and give credit to your station for its data. Otherwise you could be seeing some other data source in WeatherForYou. When you pull up WeatherForYou do you see your station mentioned?
If you posted some of your station IDs it might be helpful for others to take a look.
Notice red arrow indicating where the data is coming from. This would be the station name in PWSweather if it is being credited.
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What I'm saying is that just because you upload to Hamweather (now PWSweather) doesn't mean that it automatically gets credited or used at WeatherForYou. You have to send an email to WeatherForYou and allow them to credit your PWSweather station.
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Hello galfert,
Yes, I'm uploading my station on WeatherForYou as well.
https://www.pwsweather.com/station/pws/PLUGNICKEL (https://www.pwsweather.com/station/pws/PLUGNICKEL)
https://www.weatherforyou.com/reports/index.php?forecast=zandh&pands=jamestown%2C+colorado&Submit=Get+Weather (https://www.weatherforyou.com/reports/index.php?forecast=zandh&pands=jamestown%2C+colorado&Submit=Get+Weather)
It's the strangest thing...
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Looks good as in your station is being referenced and credited for the data. I think this is a question for WeatherForYou. That is strange.
Maybe WeatherForYou does not use barometric pressure from your station and they only use temperature? Or maybe they aren't using your barometric pressure because they detected a variance that was too great for your data? These are all questions for WeatherForYou.
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They claim they use the PWS's barometer.
From an email from them:
"We have different stations that send station pressure, altimeter, or mean sea level pressure. Our system will attempt to determine what version your station is sending based on the software. That said, currently, the PWSweather.com website displays the Mean sea level pressure."
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WeatherForYou uses the raw data sent by your station's software, device or service. PWSweather has begun doing further processing to calculate and standardize the readings (based on sea level, I believe). I know the PWSweather.com developers are still working out some of the bugs in the conversions.
While WeatherForYou does get the data through PWSweather.com I take the raw data sent by your station as long as I've been requested to use that. If a request isn't made I'll still use data from PWSweather.com but it will include any calculated change that system makes.
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Barometric pressure measurements always confuse me.
The data that I'm sending both PWS and WFY is adjusted for elevation above sea level.
I know that PWS is using MSLP.
How do they differ?
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I think this may warrant looking at your VWS software configuration and also learning a bit more about your hardware.
What hardware is your station? What logger are you using? (I miss the that about the old PWSweather where it gave you information about the hardware used by the station).
I've never used VWS but I've glanced at the manual. It says that VWS will calculate Sea-Level Barometric Pressure. Hmmm...that is a clue right there. This means it is important for your software to have the correct elevation. It is also important to know more about your hardware. That is why I asked what is it? This might tell us what your station is passing to VWS. As it could be passing an already corrected pressure or it may be an uncorrected station pressure (QFE). I would also like to know if you have changed any of the setting in VWS in its calibration settings (Gain and Offset dialog settings). Hopefully the VWS Calibration setting is set to Gain 1.00 and Offset 0.00. I prefer to make these corrections at the console and never do these at the software level.
What I'm thinking is that you may be doing some barometric offset in VWS that you see on your software but it is not being passed to PWSweather.
Here is another issue that I see. This warrants looking into because I see that your VWS pressure along with what you see at PWSweather as being too low of a pressure to be accurate. I don't think your station is properly calibrated is what I'm saying. I'm looking at KBDU and KLMO and you are too low compared to them. Don't mention elevation differences (that is not an issue). I know people like to throw out elevation differences between them and the airport but that is not an issue.
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My station is a Davis Vantage Pro2 and it's got the correct elevation of 7300' entered (hence my low pressure reading).
Today my pressure is 29.72".
I have no offsets entered into anything since there is no official reporting station near me at my altitude for fine calibration.
VWS was getting pretty old, so I downloaded Weather Display software and the problem still exists.
It's reporting the corrected value to VWS as well as Weather Display and I Wire Sharked the packet it's sending and it's also sending the same elevation corrected value.
There's something going on with PWS Weather that's not occurring with WeatherForYou.
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Forgot to say the My station is 2000' higher than the KBDU Boulder Airport.
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My station is a Davis Vantage Pro2 and it's got the correct elevation of 7300' entered (hence my low pressure reading).
Your high elevation is not a reason for low pressure if you have properly calibrated for sea-level pressure equivalence. Sure I would expect a low pressure for your location at your high elevation if you were reporting your QFE (station pressure also called Absolute pressure)...but nobody does that. We are only concerned with Sea Level pressure which is a number we reach because of your elevation adjustment.
Your 7300 feet almost matches what I see using FreeMapTools of 7329 feet.
https://www.freemaptools.com/elevation-finder.htm
That is enough to make 0.03 inHg difference. But I'm seeing a greater discrepancy than that...So being off by 29 feet is not the issue. It is just a small factor. There is something else going on.
Today my pressure is 29.72".
Today your pressure is 29.72 where? As in where did you pull that number from? Your VWS software, your Davis VP2 display? or Somewhere else? Because according to PWSweather you max for today only reached 29.56 at around 1:55AM (your time).
I have no offsets entered into anything since there is no official reporting station near me at my altitude for fine calibration.
Offsets or no offsets has nothing to do with stations near you at your altitude or not. I say this because I don't believe in any offsets in software. My recommendation is to make all those corrections and calibrations at the console which is the VP2 display console in your case.
VWS was getting pretty old, so I downloaded Weather Display software and the problem still exists.
I only see that you have uploaded to PWSweather. It would be helpful to see what happens when you upload elsewhere. I would recommend uploading to Weather Underground as a comparison. Helps to see if a site is manipulating your data or not.
I'm curious to hear you take a reading from 3 places at the same time and report what you see...
VP2 display console pressure reading:
PWSweather pressure: (mention which software uploaded; VWS or Weather-Display)
WeatherForYou pressure:
Weather Underground pressure: (yeah I threw this in as 4th comparison that would help, and mention which software uploaded).
It's reporting the corrected value to VWS as well as Weather Display and I Wire Sharked the packet it's sending and it's also sending the same elevation corrected value.
There's something going on with PWS Weather that's not occurring with WeatherForYou.
It would be interesting to see if VWS uploading to PWSweather is different than Weather-Display uploading to PWSweather. I think you mentioned you tried this and it didn't make a difference. But I'm not clear now from reading what you wrote if that is what you are saying. Just trying to see if the issue with PWSweather is there with both software. But it would be important to know how each software is getting the data. Meaning how is VWS getting data? Via USB logger? And when you configured Weather-Display did you then also use the same USB logger or is it pulling data from some other means?
I'm also wondering what firmware your console and logger are running?
And lastly ...just to be sure in VWS Calibration you have Barometer Gain and Offset set to 1.00 and 0.00 respectively?
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Your high elevation is not a reason for low pressure if you have properly calibrated for sea-level pressure equivalence. Sure I would expect a low pressure for your location at your high elevation if you were reporting your QFE (station pressure also called Absolute pressure)...but nobody does that. We are only concerned with Sea Level pressure which is a number we reach because of your elevation adjustment.
Your 7300 feet almost matches what I see using FreeMapTools of 7329 feet.
https://www.freemaptools.com/elevation-finder.htm
That is enough to make 0.03 inHg difference. But I'm seeing a greater discrepancy than that...So being off by 29 feet is not the issue. It is just a small factor. There is something else going on.
Currently, KBDU pressure is 29.76" mine as reported by my weather station, Weather Display, and WeatherFor You is 29.71" for a difference of 0.05".
I think that that difference is reasonable since I've never fine tweaked it.
We had a high (edited, mistakenly said low) pressure ridge settle in to Colorado the last few days but it's now moved out.
However, getting back to the point, PWS Weather is currently reporting 29.0".
Today your pressure is 29.72 where? As in where did you pull that number from? Your VWS software, your Davis VP2 display? or Somewhere else? Because according to PWSweather you max for today only reached 29.56 at around 1:55AM (your time).
As reported by my weather station (Vantage Pro2), Weather Display, and WeatherForYou.
Again, PWSweather is the problem.
I only see that you have uploaded to PWSweather.
Other than WeatherForYou, I'm not uploading anywhere else.
I used Weather Underground for many years until...well, you know.
I'm not using VWS now, but I checked and all the gains were 1 and all the offsets were 0.
Weather Display that I'm currently using also has no offset (it doesn't have a gain control).
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As a test create a new PWSweather station ID. Don't delete your current one. You can have more than one station ID. Then start uploading to the new station ID as a test. See if that makes a difference. You only need to do this momentarily to test. Then you can switch back your software to upload to your current PWSweather ID.
I know a lot of people have given up on WU and I understand that. But if you could just upload to WU as a test to see if it a different site treats you data the same or differently we might learn something. Or since you now are using Weather-Display you could upload to WeatherCloud also as a test.
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I temporarily created a WU account and WU agreed with everything except PWS Weather.
Gonna have to email them again.
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What about a second PWSweather station ID to test if somehow that original ID has been messed with?
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I doubt there is anything wrong on his end.
My PWS hardware console currently shows 30.09 inches Hg which is also what the WU shows. My PWSWeather console shows 30.04. It is always lower by about that much. The upload is done to each separately by Cumulus. PWS Weather is changing the pressure figure before display. That 0.05 inches Hg does not correspond to the difference between sea level and 655 feet AGL (my elevation), which would be closer to 0.5. However, I am already sending them the correct value.
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If you'd submit a support request with this info it may be helpful to the developers.
I doubt there is anything wrong on his end.
My PWS hardware console currently shows 30.09 inches Hg which is also what the WU shows. My PWSWeather console shows 30.04. It is always lower by about that much. The upload is done to each separately by Cumulus. PWS Weather is changing the pressure figure before display. That 0.05 inches Hg does not correspond to the difference between sea level and 655 feet AGL (my elevation), which would be closer to 0.5. However, I am already sending them the correct value.
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Will do. Thanks. It wasn't enough of a difference to really worry about but in the context of this thread it is at least another data point for them to work with.
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I sent them the following:
Currently as I type this, my PWS PlugNickel is reporting a barometric reading of 29.1".
KBDU Boulder Municipal Airport at 2000' lower in elevation than my station is reporting 29.85".
My station on WeatherForYou is reporting 29.78".
My Vantage Pro2 as well as my software "Weather Display" is also reporting 29.78".
So, my weather station and WeatherForYou is pretty accurate for the elevation difference (I'm at 7299' elevation) as compared with KBDU Boulder Municipal Airport however PWS Weather is way off.
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What about a second PWSweather station ID to test if somehow that original ID has been messed with?
I tried but after an hour, my new station didn't show up.
Gave up because I don't want to have my "real" station not being updated.
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After looking at this further it seems pretty convincing that PWSweather is messing with [some] station's barometric pressure uploads.
I found your neighbor running an Ambient WS-2902 that is uploading to both WU and to PWSweather. That station's barometric pressure also does not match with both services.
Neighbor on WU: 29.52 inHg
https://www.wunderground.com/dashboard/pws/KCOJAMES23
Same neighbor on PWSweather: 28.87 inHg
https://pwsweather.com/station/pws/kcojames23
For whatever reason PWSweather is messing with people's data. Interestingly though when you pass it along from PWSweather over to WeatherForYou it is the original data as uploaded.
This neighbor is experiencing the same amount of difference as the OP between their WU and PWSweather uploads of about 0.64 to 0.65 inHg. That is about 22 hPa of difference and is equivalent to messing with a station's elevation to about 616 feet! This should not be occurring. PWSweather needs to give us some answers. If this is an oversight I hope that they take notice and fix it.
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Thanks galfert for noticing that.
I never look at their PWS since they never calibrated their barometer for elevation properly.
But yes, it's screwed up the same way.
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Well, got an email from PWS Weather.
They said that they do have a problem in the software.
They said that since different stations send station pressure, altimeter, or mean sea level pressure, their software tries to determine what's being sent and then correct it to mean sea level pressure.
Unfortunately, when receiving mean sea level pressure as in most cases including mine, it thinks that it's getting altimeter pressure and correcting for that.
They said the problem should be corrected next week.
Thanks for the help everyone.
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Great job getting to the bottom of the mystery. I'm glad they provided this answer.
I think it is very thoughtful that they are attempting to fix stations that send them the wrong data. Just seems like they need to tweak it to work better and not mess with good data.
This is probably only something that is an issue or noticeable at greater elevations such as yours as the calculations for Altimeter and Sea Level pressure will yield much different results.
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Yeah, I suspect that they were simply using a "range" of values to try to determine what data was being sent instead of adjusting those ranges according to reported station elevation.
But then it could have been any of a host of possibilities.
I'm glad their implementing quality control as well though with this and all my messing around, I've got a lot of bad pressure data in their file ;-)
Fortunately, I save all my weather station data locally, so it's all good.
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Still not fixed...
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I would email them.
I have also submitted a couple unrelated bugs to them and they keep saying that they are going to get to them and they still haven't. So there are several pending issues that they just aren't getting to in a hurry.
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Yep, emailed them yesterday.
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Well, been over a month since I first reported this problem with everybody's station who's at high elevation (as near as I can tell) barometric pressure being wrong and still no fix.
Never got a reply from my last email to them.
Just noting this in case someone comes here looking for a reason that theirs is off.
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Instead of email it's best to submit issues through the support ticket system. That way it can be tracked and assigned to the person best able to handle it.
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That is what I've always done, submit form via website ticket system. I always get an initial human response thanking me for the submission and letting me know that the problem will be addressed in the next update. Then a few days later I get a survey question which I always fill out and express my disappointment. Because the issue does not ever get resolved. I don't understand getting a survey when the issue is unresolved. The ticket must be getting closed to then trigger the survey. This stuff isn't critically affecting me other than to make me just feel less enthused.
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I already have a support ticket, so I just replied to the existing support ticket email rather than have another one opened.
I did get an email back the other day. They replied:
"Our new Station Dashboard is in final development and going to QA for review next week with a goal to release at the start of August. The new dashboard will allow you to set the type of pressure you are sending for the station, which will help allow users to resolve this issue.
The API team is adding an additional check to the existing platform for your software / hardware combo, to define it as MSLP vs altimeter. This is set to be pushed to production on Monday, July 20th. This took a bit longer, as the team wanted to perform some verification with other PWS users who have the same hardware-software combo before making a wholesale change.
I will provide an update on Monday once this has occurred. Also, We have a separate task to run a script to update all the data you previously sent, which will occur after the update next week is confirmed to fix your pressure issue for new observations."
So, I'll see what happens.
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I already have a support ticket, so I just replied to the existing support ticket email rather than have another one opened.
I did get an email back the other day. They replied:
"Our new Station Dashboard is in final development and going to QA for review next week with a goal to release at the start of August. The new dashboard will allow you to set the type of pressure you are sending for the station, which will help allow users to resolve this issue.
The API team is adding an additional check to the existing platform for your software / hardware combo, to define it as MSLP vs altimeter. This is set to be pushed to production on Monday, July 20th. This took a bit longer, as the team wanted to perform some verification with other PWS users who have the same hardware-software combo before making a wholesale change.
I will provide an update on Monday once this has occurred. Also, We have a separate task to run a script to update all the data you previously sent, which will occur after the update next week is confirmed to fix your pressure issue for new observations."
So, I'll see what happens.
"Our new station dashboard" Any updates on this?
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Last I heard from them was on the 27th of July and they said that they are planning on making every station display airport altimeter readings but it ain't done yet.
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Last I heard from them was on the 27th of July and they said that they are planning on making every station display airport altimeter readings but it ain't done yet.
That is ridiculous! Every station to show airport pressure? [-X
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Yeah, that's their plan.
They said they're doing it because that's what most people expect to see since it's the pressure reported by the news stations.
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Well then why bother even collecting personal weather data then for the other sensors. Are they a going to change their name to AMSweather (Airport METAR Station weather)?
There is no point to uploading from a personal weather station if this happens. They have no business selling data.
The new UI redesign is very nice. It showed promise to finally be a contender to WU. Now this? Who is running this place?
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They're using the airport FORMAT and DATA TYPE, not the actual airport data. It'll use your pressure reading but display it in the same way as the airport does (altimeter).
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OH!.... Hmmmm... Like CWOP then. Eh...still not impressed. I don't expect Altimeter when I see weather data. Meteorologists use Sea Level Pressure not Altimeter.
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But, like what was said, the public expects what they see on TV to match what they'll see on weather sites.
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This change is going to still play out wrong. Most people that report to CWOP understand that the pressure there is not the same as the pressure they see on their display console. Only way to make to match is to zero out your elevation or you have a Vantage Vue which is the only console I've heard of that has a setting for Altimeter. Even still you still have newbies on CWOP that have to contend with Altimeter and they have to be told why it doesn't match their displays. Every other online service uses Sea Level Pressure.
Many Airport METAR report both Altimeter and Sea Level Pressure. They don't all but I'd hope that more and more airports update their systems to continue this trend.
The public can expect what they want. But personal weather hobbyist are not the public.
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I like to come up with solutions to problems. I recognize that for high elevations dealing with Altimeter vs Sea Level Pressure can be an issue. Especially in the cases where the METAR does not provide Sea Level Pressure data. Like I said in many cases the METAR does provide both Altimeter and Sea Level Pressure.
My suggestion is for PWSweather to have an online barometer calibration assistance calculator tool. The station owner can then enter the following information in the calculator tool:
- Airport Altimeter pressure
- Airport elevation (with some tips an information on where to get this info)
Then instantly this online calculator tool can compute and provide the station owner the Sea Level Pressure for that METAR.
The tool is using the information provided to find out the airports Absolute Station Pressure and then it calculates Sea Level Pressure.
The station owner can then calibrate their station that was designed to show and work with only Sea Level Pressure to be properly calibrated.
If you want to make the online calculator tool even better you can simply ask the station owner for their METAR ID code. The calculator would then automatically look up the current Altimeter pressure and it would also have an internal database with all airport METAR elevations and simply produce the Sea Level Pressure for that METAR. The results should then show that the METAR is showing such and such Altimeter pressure but to go ahead and calibrate with this other computed Sea Level Pressure equvalance. MesoWest does this.
I've had this idea for a while but I hadn't thought of how or where to begin to hopefully make the use of this calculator tool become a reality. Or to then spread the word for its use.
Somehow though this whole Altimeter vs Sea Level Pressure does not seem to be an issue with all the other weather station online services. Only CWOP requires Altimeter. With other services they mostly spell out Sea Level Pressure or they omit defining it or they call it Relative Pressure.
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They don't monitor here so submitting your idea as a support request would be best.
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I submitted a ticket sharing my idea. I hope they listen. They are about to open a can of worms if they switch to Altimeter.
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I have more information on this matter. There was some misinformation and I can understand why it happened and I can now see that it was not deliberate. They are implementing some good changes soon. I think it will make everyone happy. The matter of choice will be made available. More to come. PWSweather / Aeries Weather are working hard at improving their services.
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They are implementing some good changes soon.
Looking forward to the changes. Hopefully soon.
WU and Weathercloud match my console (AmbientWeather)
I am also noticing the pressure on PWSweather is low compared with my console.
This is what AmbientCWOP shows:
Barometer (REL) 30.33 inHg (1027.1 mb) *SLP*
Barometer (ABS) 24.13 inHg (817.1 mb)
Pressure (Altimeter) 30.72 inHg (1040 mb)
PWSweather: 1015.7mb(MSLP)
Just echoing what others have noticed.
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Stopped checking to see if it was fixed yet for a long time until now.
Airport - 29.89 in
My Station - 29.86 in
Weather For You - 29.86 in
PWS - 30.05 in
So, yeah...still not fixed.
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Stopped checking to see if it was fixed yet for a long time until now.
Airport - 29.89 in
My Station - 29.86 in
Weather For You - 29.86 in
PWS - 30.05 in
So, yeah...still not fixed.
Interesting(?) that your PWS pressure is higher than your console.
My PWS pressure is lower than console whenever I check it. My elevation is at 6750 ft. (Calibrated my barometer to Sea-Level Pressure METAR with proper online calculator elevation offset between ABS-REL in console.)
How can I tell what is being sent to PWSweather from my console?
Actually, my data goes from console>ambientweather.net>PWS using an API key(?). I'm not sure what gets sent to -or pulled by- PWS but whenever I check PWS pressure it doesn't match my Relative or Absolute pressure from console. It doesn't match my Altimeter Pressure that gets sent to CWOP either.
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I suspect that PWS Weather is getting your console pressure accurately.
I don't know what algorithm they are running on the pressure data we send them, but I do know that it results in inaccurate pressure readings on their site.
Still waiting for those "good changes" that are coming soon:-)
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The matter of choice will be made available. More to come. PWSweather / Aeries Weather are working hard at improving their services.
It is now 2021-01-03.
Yes, there is now an option in your PWSWeather Station edit screen to set pressure to MSLP, Station/Surface Pressure, or Altimeter. I have selected MSLP. There's a disclaimer there that it's still a beta option and they're working on correctly displaying the data based on your selection. I'm see that option has been available since November.
1 months later...
My GW1000 says 30.133, WU says 30.13, and PWSWeather says 29.96
Note that KFHU, my local METAR, says 30.14 on PWSWeather. I'm guessing because it is a METAR, the data is pulled from elsewhere, so they get displayed properly.
...just one of the reasons I still use WU. They, at least, display the proper pressure reading.
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The matter of choice will be made available. More to come. PWSweather / Aeries Weather are working hard at improving their services.
It is now 2021-01-03.
Yes, there is now an option in your PWSWeather Station edit screen to set pressure to MSLP, Station/Surface Pressure, or Altimeter. I have selected MSLP. There's a disclaimer there that it's still a beta option and they're working on correctly displaying the data based on your selection. I'm see that option has been available since November.
1 months later...
My GW1000 says 30.133, WU says 30.13, and PWSWeather says 29.96
Note that KFHU, my local METAR, says 30.14 on PWSWeather. I'm guessing because it is a METAR, the data is pulled from elsewhere, so they get displayed properly.
...just one of the reasons I still use WU. They, at least, display the proper pressure reading.
UPDATE: May 8, 2021
If you click on the gear icon on the dashboard yes, you can now choose MSLP, Altimeter or Station [Pressure] but...if you click on MSLP you get Station Pressure (ABS). If you click on Altimeter you get REL. If you click on Station you get ??.
Here are my current readings from the Ambient WS-2000 display console:
ABS = 993.8
REL= 1016.6
Here is what the PWS Weather dashboard shows:
MLSP=993.7 (rounding?)
Altimeter= 1016.6
Station=1017.2
Interestingly ,WeeWX shows Barometer(MSLP) = 1017.2