BoM blatant cherry picking and ignoring urban warming effects to claim hottest January day for Mackay Queensland

A reader sent in this news item – Mackay sets January heat record – quoting the Bureau of Meteorology saying “Mackay has set a new record for its hottest January maximum temperature. The weather bureau’s Jeff Sabburg says the mercury hit 39.6 degrees on January 28.”
To understand how dodgy this claim is – there are two BoM recording stations current at Mackay.
Mackay M.O. station 033119 (MO = Met. Office) with data from 1960 and the other is Mackay Aero station 033045 at the airport with a decade of data in the 1950’s then a 30 odd years gap to 1996.
The hottest Jan day claim for the 28th was fom Mackay Aero – there was no hot Jan day record at Mackay M.O. the BoM purpose built official meteorological station for Mackay which had longer continous data than Mackay Aero.
To read more
Let’s take a quick look at the Aero site map – click on the link at – A basic site summary is available in a pdf document.
We see that in 2000 the site was openly exposed

Then in 2001 there is a new bitumen road a few metres to the south and a 1m high gravel topped levee bank to the north.
In 2004 the map indicates that the levee bank has a road along it.
But when we check the 2007 map –

we find the instruments are now squeezed between two raised bitumen roads. All these changes to the instrument environment add up to steadily increasing micro-site changes that will add an artificial warming effect into the Mackay Aero temperature data. Of course both Mackay M.O. and Mackay Aero will be impacted by the urban heat island (UHI) effect due to the growth of Mackay. The extra warming in Mackay Aero is likely due to more warming micro-site changes there compared to Mackay M.O.

The warming of Mackay Aero over Mackay M.O. is proved by the trends exhibited in following graphics.

Mackay Aero warming compared to Mackay Met Office January mean maximum temperature 1996-2013

Mackay Aero warming compared to Mackay Met Office annual mean maximum temperature 1996-2012

Mackay Aero warming compared to Mackay Met Office annual mean minimum temperature
1996-2012
In January I posted – BoM quotes Leonora temperature record at a junkyard – JunkScience indeed – anything to beat up heat. The BoM is at least consistent in relying on poor science.

This site is experiencing many spam comments which are caught by the spam catcher – sometimes good comments get caught too – so if your comment does not appear email me wshblog2013 at the usual warwickhughes.com

6 comments to BoM blatant cherry picking and ignoring urban warming effects to claim hottest January day for Mackay Queensland

  • Ken Stewart

    Warwick
    Good old Mackay eh? I know it well, having lived in the district from 1987 to Sept 2012. Often flying in to or out of Mackay we could see the construction work, excavations, pils of dirt etc around the site so I’m not surprised. It might indeed have been a record for the past 17 or so years, but it would be very difficult to claim there were no local site influences on temperature recordings. The MO site is not much better, close to a bitumen road and downwind from the large Met office buildings. Good work Warwick.

    Ken

  • There seems to an overload of gobbledeegook going on here. The Weatherzone media release says a new record of 39.6C was established at Mackay on 28 Jan, beating the previous record of 38.5C set in Jan 2006.

    The raw records show the hottest Jan 2013 day was 36.9C at Mackay Aero 33045 on 28 Jan and 35.5C at Mackay MO 33119 on 28 Jan.

    At Mackay Aero in 2006 the hottest day raw was 35.8C on 7 Jan and at Mackay MO it was 35.7C on 7 Jan. In ACORN 33119 (i.e. MO), 7 Jan 2006 is 35.7C.

    OK, there was a 4.1C upward adjustment to raw at Mackay MO on 28 Jan 2013 to achieve 39.6C, maybe ACORN, maybe AWAP.

    The hottest ever ACORN adjusted day in Mackay was 39.3C on 16 Dec 1964 (39.4C in MO raw). The next hottest ACORN day was 38.7C on 5 Feb 1990 (38.7C in MO raw). Third hottest was 38.5C on 20 Dec 1995 (38.5C in MO raw).

    They are Dec and Feb days. The previous hottest Jan day in the ACORN adjusted daily records was 37.5C on 1 Jan 1956. Raw max at Mackay Aero on 1 Jan 1956 was 35.6C (no MO raw so presumably adding 1.9C to Aero to ACORN adjust for missing data).

    In raw at Aero, the previous hottest day was 35.8C on 7 Jan 2006. At MacKay MO raw, the previous hottest day was 37.2C on 1 Jan 1985.

    In the Post Office 33046 raw max records, the hottest day was was 37.7C on 21 Jan 1915 (adjusted down to 36.6C in ACORN).

    According to the BoM, Mackay’s record of 39.6C on 28 Jan 2013 was “the actual temperature”. You could have fooled me.

    Weatherzone says the mean at Mackay for the month of January 2013 was 31.6C, which was 1.5C above the long-term average. They’re talking about the mean max, not the mean. Raw at Aero was 31.6C and MO raw was 30.9C.

    The Aero raw Jan mean max for all years is 30.1C, which is 1.5C below Jan 2013. At MO the raw Jan 2013 mean max was 30.9C and for all years is 30.0C.

    Why with dailies do they mysteriously upward adjust temps but with the monthly mean max they go back to unadjusted raw?

    With the monthly average, they seem to reference Aero instead of MO even though MO is the ACORN station and was 0.7C cooler than Aero in Jan 2013.

    The Jan 2013 raw max at Aero was 31.6C.
    Previous Aero raw Januarys – 2004 31.7C, 2006 31.8C.

    The Jan 2013 raw max at MO was 30.9C.
    Previous MO raw Januarys
    1971 31.0C ACORN 31.0C
    1980 31.1C ACORN 31.0C
    1982 31.3C ACORN 31.3C
    1985 32.1C ACORN 32.1C
    1987 32.8C ACORN 32.8C
    1992 32.1C ACORN 32.1C
    1994 31.3C ACORN 31.3C
    2002 31.9C ACORN 31.9C
    2004 31.3C ACORN 31.3C
    2006 31.6C ACORN 31.6C

    Stepping back to Post Office days
    Previous PO raw Januarys
    1924 31.9C ACORN 30.8C
    1931 32.0C ACORN 30.9C
    1935 32.0C ACORN 31.0C
    1940 32.1C ACORN 30.9C
    1944 31.7C ACORN 30.5C
    1945 31.7C ACORN 30.4C
    1947 31.8C ACORN 30.5C

  • WSH

    Gidday Chris, I used raw weather data all through – ignored ACORN which IMHO is a machine-written heap of garbage that one day the BoM will be forced to move on from as they have moved on from the several non-climatic tweaked and warmed versions they have created over 20 years. To start going into Mackay ACORN is another separate exercise altogether – which I agree might be worth excavating. I see Mackay ACORN uses Met Office then Post Office with help from a few years of Te Kowai in between.
    I am not sure what you mean by –
    “OK, there was a 4.1C upward adjustment to raw at Mackay MO on 28 Jan 2013 to achieve 39.6C, maybe ACORN, maybe AWAP.”
    The 39.6 was read at Mackay Aero on the 28th, nowhere else. Mackay MO on 28 Jan 2013 recorded a max of 35.5.
    The way I read BoM processes – the 39.6 can not get into ACORN.

  • Mackay Aero 33045 raw max was 36.9C on 28 Jan, not 39.6C.

    www.bom.gov.au/climate/dwo/201301/html/IDCJDW4077.201301.shtml

    I’d assume everybody is reading their 6s and 9s upside down only the Weatherzone statement (also ABC – www.abc.net.au/news/2013-02-05/mackay-sets-january-heat-record/4501118) says the previous January record was 38.5C in 2006.

    Mackay Airport 7 Jan 2006 raw was 35.8C and Mackay MO 7 Jan 2006 raw was 35.7C. Mackay MO 7 Jan 2006 ACORN was also 35.7C.

    I can’t accept that everybody’s got their 6s, 9s, 5s and 8s mixed up, so I’ll interpret 38.5C as a 2.7C upward adjustment of airport raw in 2006.

    If the airport raw 28 Jan 2013 max of 36.9C is now 39.6C, that’s also a 2.7C upward adjustment.

    ACORN is Mackay MO 33119 which, as you say, had a raw max of 35.5C on 28 Jan 2013.

    35.5C + 4.1C = 39.6C. However, if Weatherzone/BoM is talking about the airport instead of the official Mackay ACORN MO, the adjustment is in fact 2.7C. I erred above by assuming they’re talking about the MO since it’s considered a superior location and contributes to Australia’s temp feed for global indices.

    Where does 2.7C come from? Raw and ACORN at MO have been the same for years. However, they’re talking about Mackay Aero, even though none of the media mention that little detail. The BoM says “the mercury hit 39.6 degrees on January 28″. Really? I think the adjustments hit 39.6 degrees on January 28.

    I reference AWAP because it may deliver a big enough area average adjustment … e.g. 7 Jan 2013 was Australia’s hottest Jan day ever at 40.3C, up from a raw averaged 35.1C (www.waclimate.net/hottest-day.html). Area averaging lifted Queensland’s mean max on 7 Jan 2013 from raw 33.0C to 36.82C. I’m clutching at straws to understand adjustments until the BoM hopefully releases a new AWAP dataset in a few months.

    Mackay Aero on 28 Jan 2013 had a raw 36.9C which could be claimed a Jan record against the previous raw record of 35.8C at Aero on 7 Jan 2006. I accept that despite the airport’s patchy history including just 30 years of record, but I can’t figure out where the extra 2.7C comes from.

    MacKay MO is the ACORN station and has an unbroken annual record from 1959. It seems a bit odd to be claiming a new Mackay max record when the town’s MO station was 37.2C on 1 Jan 1985 (also 37.2C in ACORN).

    The post office raw max was 37.7C on 21 Jan 1915. It’s been adjusted down to 36.6C in ACORN but I agree with you that the ACORN dataset is mostly BoM guesswork.

    ACORN adjustments, AWAP area averaged adjustments, inexplicable adjustments … we’re experiencing anthropogenic climate adjustment, not anthropogenic climate change.

  • WSH

    This gets even more amazing – so the 39.6° was a “misread” of 36.9°. I have kept screen shots of the media articles.
    I wonder if a correction will appear ?
    Incidentally – TE KOWAI EXP STN 033047 only 5 or 6km inland from Mackay yet has Oct, Nov, Dec and Jan all with +40° days over the 1908-2012 period. Data got patchy from the mid 1970’s.

  • Ian George

    Thanks to Warwick for chasing this up.
    None of the records show Mackay with a 39.6C for 28th Jan, 2013.
    www.bom.gov.au/climate/dwo/201301/html/IDCJDW4077.201301.shtml shows 36.9C.

    www.weatherzone.com.au/station.jsp?lt=site&lc=33045&list=ds&of=of_a&ot=ot_a&mm=01&yyyy=2013&sub=go shows 36.9C.

    www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=122&p_display_type=dailyDataFile&p_startYear=2013&p_c=-218390402&p_stn_num=033045 shows 36.9C. (The Mackay MO says 35.5C.)

    ACORN have no data for Jan 2013 that I can find but shows 7 Jan 2006 at 35.7C – the raw data says 35.8C (not the 38.5C they claim) as shown here. See here
    www.bom.gov.au/climate/averages/tables/cw_033045_All.shtml

    The highest max Jan temp I can find is Jan 1915 at 37.7C at Mackay PO.
    www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=122&p_display_type=dailyDataFile&p_startYear=1915&p_c=-218403620&p_stn_num=033046

    Here is Mackay’s ACORN record. Keep on eye on this for any ‘adjustments’.

    www.bom.gov.au/climate/change/acorn/sat/data/acorn.sat.maxT.033119.daily.txt
    Editors note: The 39.6 was shown yesterday Ian.

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