Wonderground Disappearing, The ASOS

Well, there are times….

At this point, I’ve got to wonder if some “political engineering” is going on over at Wunderground.


They have “disappeared” the ASOS stations.

(UPDATE: In searching at NOAA it looks like it may be that NOAA began the “disappearing” via renaming and / or that the M-type station feeds, that may have been the metric feed, have been ‘disappeared’ leaving only the F feeds. That still leaves open the issue of what Wunderground did with the history of the MKSJC and MKPHX stations…)

In a prior posting I’d shown how anyone could do an A/B compare of the ASOS stations (located at airports for use by pilots) with the surrounding non-ASOS stations and see the airport bias directly. This bias came from a couple of sources. One (and IMHO, the most important) is all that gigantic area of concrete, tarmac, rooftops, roads, parking lots, cars, tons of jet kerosene being burnt, ground support vehicles, etc. The other being that the ASOS are, by design, going to “report high” and it is a good thing for pilots. The design goal of the ASOS is safe flying. Your wing does not care if it is 2 degrees cooler over in the shade, it only cares that it is hotter over the runway as that is where it is going to do the lifting to get you off the ground. You simply MUST know the air temperature where the wing will be to do a proper ‘density altitude’ calculation. If you think it is colder than it really is, you will not ‘rise’ as fast as expected (or in some cases, at all) and will either crash at the end of the runway, not clear the 50 foot obstacle at the end of the runway, or just generally have a ‘brown pants’ moment.

So I’m all in favor of the ASOS reporting, as they did, in what looked like whole degrees C rounded up as that is the direction of pilot (and thus passenger) safety.

What is wrong is to use those data for “climate change” research…

OK these are two of the prior postings (and there were a couple of others):



For San Jose, for example, there were two codes for the temperatures. One for the ASOS, the other for a different station or different processing history at the airport (it was bit unclear). MKSJC was the ASOS. KSJC was the “other one”. You could do a very nice A/B of the two, and then compare them to nearby non-ASOS stations.

OK, so I went back to that SJC comparison page. We’ve had a nice block of “very cloudy” right next to a nice block of “sunny” and I figured I’d do an A/B compare of sunny vs not and see if the ASOS had demonstrable “sunshine bias” or not, and compare both of the “airport stations” to the nearby non-airport.

BUT, what did I find?

MKSJC is not reporting anymore (at least not at Wunderground). Furthermore, before when you would look at the list of “nearby stations” to any given station, you would find various stations with ASOS in their name. What do I find NOW when I search for ASOS?

There has been an error!

City Not Found

We’re sorry, but the page you have requested was not found.

The search for “ASOS” did not return results.

Common Search Problems:

Or for the station by station ID?

There has been an error!

City Not Found

We’re sorry, but the page you have requested was not found.

The search for “MKSJC” did not return results.

Common Search Problems:

Though a similar search on the KSJC tag does work:

Guess when you have “inconvenient data” the best thing to do is just delete it… Seems the norm in “climate science”, but that Wunderground has now become Wondergone too is a grave disappointment.

OK, doing a direct search on the tag via a URL gives:

2011 MKSJC Wundergone data gone

2011 MKSJC Wundergone data gone

But the “drop down” showed that both 2010 and 2011 were “sort of there” in that the system claimed to be able to report them, just all of 2011 was ‘null’. What about 2010?

MKSJC 2010 Wundergone Graph

MKSJC 2010 Wundergone Graph

Gee… that’s interesting… The start and the end of the year are gone, but the middle is still there…

And what happened to all the PRIOR years? That ASOS has been there for quite a while… Gone, it would seem with the wind…

OK, I’ve only “spot checked” a couple of the other ASOS. It looks like generally the Data Langoliers have cleanly removed them. Look for the rest of MKSJC to evaporate shortly too (now that I’ve shown their “QA” process missed it, probably via only checking that January was gone… )

WHY has Wunderground removed the most important thermometer for pilot and passenger safety? I can only speculate that they felt the needs of aviation safety were not important to them but that “other needs” were better met with the deletion of “an inconvenient datum”…

Now most pilots will use the in-cockpit thermometer (as it is closest to the wings) for take-off; and for in-flight reports on destinations, they will likely call the airport and ask for a current reading. I’m not expecting too many folks to be doing density altitude calculations using Wunderground. OTOH, if I were sitting at home and thinking of making a flight, I’d have gone there and gotten that data for a ‘first cut’ of “does it look ok?”. And that is NOT a hypothetical. When I was taking ground school, a ‘nearby’ airport tended to be “hot and high” and every few months someone would land there, then find out they could not take off again. The Base Operator would send his very slim wife up. The folks who rented the Cessna 150 would drive the wagon back, and she was light enough that she could fly it out. (Load is about 500 lbs, so two heavy guys and you don’t fly in marginal conditions, where one 100 lbs lady would be OK). As he taught the ground school, we did a lot of “density altitude AFTER you get to your destination and want to come home” calculations as “flight planning”… and were I thinking for flying to Phoenix, I’d have likely just hit Wunderground ASOS for an easy data feed.

OK, so anything else to report on this Disappearing ASOS deal?

Phoenix Sky Harbor Airport

It used to be listed as:

ASOS_HFM PHOENIX/SKY HARB, AZ, Phoenix, AZ 72 °F / 22.2 °C 55 °F / 13 °C 57% East at 3 mph / 4.8 km/h / 1.3 m/s
29.90 in / 1012.4 hPa 0.00 in / 0 mm / hr 76 °F / 25 °C 1105 ft 33 min 55 sec ago MADIS Website

Note the token ASOS at the start of the name? Now scan those next lines out to the “ft”. 1105 Feet

What does a search on Phoenix Sky Harbor Airport give you now?

Weather Station
Phoenix (KPHX)
Elevation 1135 ft

Well, we’re now 30 feet higher… (That is for the non-ASOS “station” at Sky Harbor)

So they have swapped what station they are reporting as “at the airport”…

I’ve done an “initial peek” and it looks like stations not subject to the “ASOS Bias” have been substituted at Wundergone. That makes them useless for doing “ASOS vs Non-ASOS” and potentially useless for doing “Airport vs Non-Airport” comparisons (as we don’t really know what thermometers they are calling “at the airport” any more, now do we? It’s not the ASOS, so who knows what it is…)

They do provide nice historical graphs in a relatively easy to save fashion, but once the Data Langoliers start to bugger the history someplace, all their “tools” are just useless trash.

So, with a modestly heavy heart, I now must consign “Wunderground” to the dustbin of “Politically Contaminated Data” sites. At least until they put the ASOS back… For anyone useing “Wundergone”, realize that you don’t know what you are getting any more…

So now I’m looking for a new, unbiased, site with the ASOS data intact and with some decent historical graph tools.

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About E.M.Smith

A technical managerial sort interested in things from Stonehenge to computer science. My present "hot buttons' are the mythology of Climate Change and ancient metrology; but things change...
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8 Responses to Wonderground Disappearing, The ASOS

  1. E.M.Smith says:


    Looking at NOAA:


    gives this:

    Phoenix Sky Harbor International Airport 
    Phoenix, AZ, United States	
    Call Sign/ICS* 	: PHX / KPHX 
    WBAN* 	: 23183 
    COOP ID* 	: 026481 
    Climate Division* 	: AZ-06 - South Central 
    WMO ID* 	: 72278 
    In Service* 	: 01 Oct 1930 to Present 
    Elevation*	: 337.4m (1107') above s/l 
    Lat/Lon* 	: 33°26'N / 112°00'W 
    County*	: Maricopa

    Notice that is is saying the KPHX call sign is the ASOS? And that it is at 1107 feet ASL?

    There is some serious mixing of “who is what” going on at Phoenix Sky Harbor. Either the past is / was wrong and MKPHX was bogus (if so, where is the statement to that effect?) or the present is confused as they have the same call sign at two different elevations between NOAA and Wundergone…

    I also note that saying the ASOS has been “in service” since 1930 is a bit, er “rich”…

    I get the distinct impression that “stuff is being changed” and none too cleanly…

    So what was MKPHX and why is there confusion of it’s altitude between KPHX and NOAA / Wunderwhat?

    On this level of consistency rests the fate of the world…


    Also, searching that site for SJC / KSJC / MKSJC gives the interested set of “two stations” that share the same id number…

    For “San Jose”

    Call Sign/ICS* 	: 
    WBAN* 	: 23293 
    COOP ID* 	: 047821 
    Climate Division* 	: CA-04 - Central Coast Drainage 
    WMO ID* 	: 
    In Service* 	: 01 Oct 1905 to Present 
    Elevation*	: 15.5m (51') above s/l 
    Lat/Lon* 	: 37°22'N / 121°55'W 
    County*	: Santa Clara

    and for San Jose International:

    San Jose International Airport 
    San Jose, CA, United States
    Call Sign/ICS* 	: SJC / KSJC 
    WBAN* 	: 23293 
    COOP ID* 	: 047824 
    Climate Division* 	: CA-04 - Central Coast Drainage 
    WMO ID* 	: 
    In Service* 	: 11 Mar 1949 to 01 Oct 2007 
    Elevation*	: 15.5m (51') above s/l 
    Lat/Lon* 	: 37°22'N / 121°55'W 
    County*	: Santa Clara

    Same altitude and Lat/Lon and even the same WBAN number, but different COOP ID. BOTH claming to be the ASOS (though with a start date of 1905 for the first one that’s got to be quite a trick!) and with different service dates.

    One hopes it’s just two records for the same instrument, but “who knows”… then again, it CAN’T be the same instrument, as one starts before the other and both start before the age of semiconductors temperature recording ASOS machines…

    So I’m left wondering just what of our temperature history is an “intact record”…

  2. Ian W says:

    There does seem to be a little bit of panic change going on in the weather observation networks. As WUWT is reporting measuring equipment seems to be being removed where poorly sited USHCN sites were identified on Anthony Watts surface stations project.

    Was PHX one of those?

  3. E.M.Smith says:

    @Ian W:

    KPHX (and / or MKPHX as it’s a bit hard to know which of the two elevations was what station…) was a “known hot” station.

    Folks had noticed for a long time that the Sky Harbor airport reported a couple of degrees hotter than everything around it.

    IMHO, this was an essential artifact of all that tarmac. (Once while I was there they shut the airport down as the surface temp of the tarmac was hot enough to soften and jets were leaving tire tracks in the tarmac taxiways / parking aprons… that ought to be about 140+F for black asphalt in the sun, but the “in the air” station “only” reported 126 F IIRC. (While it was about 124 or even 122 F a ‘ways away’ from the airport.

    So, yes, it was a ‘hot station’; but it was CRITICAL for pilots to know about that 2-4 F hotter air over the runway as that is where their wings are located….

    This is the essential conflict between aviation needs (for whom the system was built) and climate “scientist” needs (who ought not to be measuring inside 5 square miles of asphalt, concrete, and jet exhaust under a desert sun…)

    So at this point I’m not sure what they are doing, but it does look like some kind of “screwing around” is happening…

  4. tckev says:

    Usually when accurate records/factual reports get changed, the mucky fingers of politics have entered the library of inconvenient facts or the clean-room of open science.
    Or maybe there just are good reasons for removing these …

  5. E.M.Smith says:


    I can see two “reasonable” explanations:

    1) The MKPHX was a “metric” feed (and thus the round up to whole degees C) for international aviation use. It really is only of benefit to international airliner / private pilots, and they can get that data “elsewhere” (that I’ve not found…). So NOAA decided to eliminate it from the domestic data stream, and Wunderground is just “purging deleted stations”.

    2) The MKPHX was a “raw feed” of the aviation rounded up data (and the ASOS does provide both a rounded up and a non-rounded feed) and after it was pointed out that this “looked bad” they saw no reason to continue it; opting instead to provide the ‘non-rounded’ feed. All well and good, but perhaps just not “advertized” enough…

    For those two to hold, there has to be a simultaneous and accidental bit of confusion over the altitude (one at 1105 or 1107 feet, the other at 1135 feet). But that could happen, Lord Knows the meta data are generally pretty crappy.

    FWIW, I don’t think the station was removed, only that data feed / history. Clearly the ASOS is still at the airport (as it’s the backbone of aviation weather now). Just something has come along and either “cleaned” it in the record, or homogenized it into some longer term local historical record. (i.e. grafted the ASOS onto the end of the prior LIG record and called it all one nice long continuous record… a “quality enhanced” record… :-}

    In any case, it makes it rather useless for a whole lot of “compare and contrast” investigations but “good enough for government work” ;-)

  6. Level_Head says:

    It will be interesting to see what feeds are still available. But this does have a disappointing feel to it — the same sort of “Phil Jones deleted all that useless history because it wasn’t value-added” feel.

    ===|==============/ Level Head

  7. Verity Jones says:

    Well well! I noted the new site look at Wunderground a while back and immediately noted the loss of the European capability for forecast models. This alone consiigned it to ‘no better than the rest’ for me. I did look at their Wundermap a few days ago looking for stations in a certain area – there were surprisingly few. Just confirmed that by looking at my local area – yup – fewer than there used to be. Darn.

  8. Pascvaks says:

    Data Control is the root of all (deleted)

    Big Brother and Big Sis are (deleted)

    The EPA is (deleted)


    I think we’re in big do-do.

    (Sarc 1/2 off)

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