General January weather

[einzack]

to add same stats:
Ave Min: 9.3°C
Ave Max: 22.2°C
Mean: 14.9°C

Min: 3.1°C on 18th
Max: 28.0°C on 31st

Rain: 141.5mm in 18 days

story of the summer is the lack of decent high pressure systems. Max pressure of 1022.5 hPa for Jan.

[Manukau heads obs]

Did you notice your records are showing a min of 3.9C on the 17th and 4.7C on the 25th? That will be lowering your avg min quite a bit..

my temp/sensor is a bit flaky at times
those are only 1 minute readings
so will have no influence on the average

[David]

Did you notice your records are showing a min of 3.9C on the 17th and 4.7C on the 25th? That will be lowering your avg min quite a bit..

my temp/sensor is a bit flaky at times
those are only 1 minute readings
so will have no influence on the average

I meant it would lower your average daily minimum (which is currently showing as 13.9)

[Nev]

Looks like this summer's relatively warm first month was more than offset by the second.
I've put together NIWA's Jan and Dec rainfall, temp and sunshine anomaly maps for comparison below…

Jan 2014 climate map (NIWA).gif

Dec 2013 climate map (NIWA).gif

Below are also some preliminary Jan 2014 temp and rainfall figures for the main centres ℅ NIWA. All their T-maxs and T-mins were below their 1981-2010 normals, apart from Tauranga's Tmax, which was normal.

Also included is Hamilton's Ruakura figures, which interestingly had a T-max more than 1C above normal, while Hamilton Aero was nearly 1C below normal. Perhaps being near the eastern fringe of suburban Hamilton, it's more prone to urban-heat-island effects during prevailing SW'ers... either that or its record T-maxs in recent months may need further investigation?

Wgtn was also the only main centre to receive above normal rainfall and below normal sunshine.

Code: Select all

January 2014 Average Temps, Rainfall and their departure from normal

Site                      T-max °C       T-min °C       T-mean °C    Rainfall mm

Auckland, Mangere        22.7  -0.7     15.7  -0.2     19.2  -0.4      42   68% 
Auckland Aero            22.9  -0.7     15.2  -0.8     19.1  -0.7      42   65%
Tauranga Aero            23.9  ±0.0     14.1  -1.0     19.0  -0.5      50   64%
Hamilton Aero            23.4  -0.9     10.0  -2.4     16.7  -1.6      39   47% 
Hamilton, Ruakura        25.1  +1.1      9.8  -3.1     17.4  -1.0      34   43%
Wellington, Kelburn      19.6  -0.7     13.0  -0.5     16.3  -0.6     133  176% 
Christchurch Aero        22.2  -0.4      9.8  -2.1     16.0  -1.2      12   34% 
Dunedin, Musselburgh     17.5  -1.4     10.3  -1.3     13.9  -1.4      59   80%    

[RWood]

Wgtn was also the only main centre to receive above normal rainfall and below normal sunshine.

I don't think so Nev. The dailies in CliFlo are missing the 24th's sun data for Kelburn, which if the reporting in the Dompost of metService obseravtions is correct, means an extra 14 hours needs to be added, bringing the monhtly total to about 236 hours, which though below the 247 hours 30-year normal, is more or less inside the 95-105% bracket.

I used to correspond with a person in NIWA who kept an eye on the manual data for sites like Kelburn, in case they never made it from the observing party to NIWA. I don't think that person is there anymore, and the frequency of missing days for the manual sites is bound to rise I fear - the Invercargill Dec manual sun record (eg) is missing a day at present, for the first time in many years. Not good enough!!

[Nev]

Thanks RWood. Yes, I did miss that 24th data, so only 'marginally' below normal sunshine then.

[Nev]

Here's NIWA's preliminary, 'January 2014 National Climate Summary'.


The national average temp of 16.6C was 0.9C below normal (thought it would've been lower), due to a strong southwesterly flow anomaly across the country, especially in the south and west.

The month's highest temp of 33.8C was recorded at Leeston, near Christchurch on the 19th, and the lowest of -2.7C at Waiouru on the 27th.

Note that Wgtn's sunshine still doesn't include the 24th's reading. The sunniest 4 available centres so far for Jan 2014 are: Whakatane (314 hours), Tauranga (301 hours), Gisborne (296 hours), and Lake Tekapo (296 hours). Queenstown recorded its lowest ever Jan sunshine (146 hours) since records began in 1930.

[David]

They have listed the average daily min temp at Palmerston North at 5.5C (7.6C below normal). Sounds way too low!

[Nev]

They have listed the average daily min temp at Palmerston North at 5.5C (7.6C below normal). Sounds way too low!

There's a day's data missing, but yes, its Jan T-max of 24.3C was also a ridiculous 1.8C above normal.

Like Ruakura, this is another NIWA/Agresearch site. It's near the city's S'n fringe and also appears overdue for a service. I suspect that a badly rotten screen, first noted at the end of 2006 and again in early 2008, still hasn't been replaced yet?

Temps at Palmerston North Aero, about 6km away near the city's N'n fringe, look to be far more reliable.
Below is a comparison of the 2 sites…

Code: Select all

January 2014 Average Temps, Rainfall and their departure from normal

Site                       T-max °C       T-min °C       T-mean °C    Rainfall mm

Palmerston North Aero     21.7  -1.2     10.2  -2.4     19.2  -1.8      60  109% 
Palmerston North NIWA     24.3  +1.8      5.5  -7.6     14.9  -2.9      52   82%

[RWood]

Here's NIWA's preliminary, 'January 2014 National Climate Summary'.


The national average temp of 16.6C was 0.9C below normal (thought it would've been lower), due a strong southwesterly flow anomaly across the country, especially in the south and west.

The month's highest temp of 33.8C was recorded at Leeston, near Christchurch on the 19th, and the lowest of -2.7C at Waiouru on the 27th.

Note that Wgtn's sunshine still doesn't include the 24th's reading. The sunniest 4 available centres so far for Jan 2014 are: Whakatane (314 hours), Tauranga (301 hours), Gisborne (296 hours), and Lake Tekapo (296 hours). Queenstown recorded its lowest ever Jan sunshine (146 hours) since records began in 1930.

Another bonkers reading - since earlyish December the Queenstown Aero EWS has not logged a single day with more than 8 hours of sunshine (it certainly was before!), even when the likes of Invercargill were logging over 14. Intercomparison with Cromwell over a reasonable timespan quite clearly shows something has gone wrong there.

Meanwhile the readings at Franz Josef have been completely ridiculous for many months now, culminating in a value of 330 hours (a nearby site more than once recorded only 60 in December!!) in December 2013, approaching double that of other West Coast stations.

[spwill]

The January pattern was very lousy for Southland and you would expect the Qtwn area to have below average sunshine even if there is some error in the readings for there. I think Queenstown will have a great Feb.

[Tornado Tim]

Also included is Hamilton's Ruakura figures, which interestingly had a T-max more than 1C above normal, while Hamilton Aero was nearly 1C below normal. Perhaps being near the eastern fringe of suburban Hamilton, it's more prone to urban-heat-island effects during prevailing SW'ers... either that or its record T-maxs in recent months may need further investigation?

After analysing Ruakura data, I have found it is in similar position (in terms of Temp fluctuation) to Matangi.
However in Matangi the High Temps can get about a degree higher, especially if we have a predominant W to NW flow.
I have a strong suspicion this because of a heat island effect in Hamilton and the wind dragging that heat off to here.

Jamies Station near Gordonton will not get this unless there is a pure southerly, and Hamilton AWS in a N which doesn't happen too often if we compare it to a Westerly. Which usually results in there readings being slightly lower than Matangi's.
I am not surprised that Hamilton's AWS temp is lower than Ruakura, but then again it shouldn't be used for Hamiltons readings. Ruakura would be much more representative. But then again Metservice doesn't want to use a NIWA station for there Highs for some reason.....

[RWood]

The January pattern was very lousy for Southland and you would expect the Qtwn area to have below average sunshine even if there is some error in the readings for there. I think Queenstown will have a great Feb.

Cromwell EWS scored 264 hours. The Queenstown "town" manual site has had deteriorated readings for some years now, but that's not my point here. Since the Aero EWS started it has shown good correlation with Cromwell - until about 4 December 2013! Since then, not one reading above 8 hours. One doesn't need Stats 101 to understand - by looking at data from the 2 sites - that Queenstown has gone loopy, though not as loopy as Franz Josef. And don't even get me started on Whakatane, whose latest annual tally is a "mere" 470 hours above older means.

I have put some of the points to NIWA, but as admitted in a radio interviews some while back, sunshine tallies are not taken very seriously by their scientists. The late Jack (?) Coulter, who authored a publication on 1941-1970 normals, must be turning in his grave.

PS edit: Good to see that New Plymouth is being investigated - site with a grossly overblown claim of 330 hrs for last February and 928 for Jan-March, much higher than any tally previously recorded by even NZ's sunniest locales - but the offenders further down the pecking order (like Balclutha) are being ignored.

[spwill]

[. Since the Aero EWS started it has shown good correlation with Cromwell - until about 4 December 2013! Since then, not one reading above 8 hours. One doesn't need Stats 101 to understand - by looking at data from the 2 sites - that Queenstown has gone loopy,

How does Cromwell compare with Qtwn in a persistent disturbed west/southwest pattern as happened in Jan and some of December ? Cromwell has more sheltering.
I'm not suggesting the Qtwn readings are not faulty but sunshine will be higher on the other side of the Gorge

[RWood]

[. Since the Aero EWS started it has shown good correlation with Cromwell - until about 4 December 2013! Since then, not one reading above 8 hours. One doesn't need Stats 101 to understand - by looking at data from the 2 sites - that Queenstown has gone loopy,

How does Cromwell compare with Qtwn in a persistent disturbed west/southwest pattern as happened in Jan and some of December ? Cromwell has more sheltering.
I'm not suggesting the Qtwn readings are not faulty but sunshine will be higher on the other side of the Gorge

qtown does much better than you might imagine. I have studied this data for decades
Qtown manual is now leading the ews after being far behind in the prior 12 plus months. The 146 & 162 (vs 264 & 232 for Crom. are absurd. Furthermore, lowest Q totals in old Januaries were not in W/SW

[RWood]

It is clear that either someone has installed an obstacle, or the device has gone rogue. Happened more than once at Franz Josef.

[Nev]

Also included is Hamilton's Ruakura figures, which interestingly had a T-max more than 1C above normal, while Hamilton Aero was nearly 1C below normal. Perhaps being near the eastern fringe of suburban Hamilton, it's more prone to urban-heat-island effects during prevailing SW'ers... either that or its record T-maxs in recent months may need further investigation?

After analysing Ruakura data, I have found it is in similar position (in terms of Temp fluctuation) to Matangi.
However in Matangi the High Temps can get about a degree higher, especially if we have a predominant W to NW flow.
I have a strong suspicion this because of a heat island effect in Hamilton and the wind dragging that heat off to here.

Jamies Station near Gordonton will not get this unless there is a pure southerly, and Hamilton AWS in a N which doesn't happen too often if we compare it to a Westerly. Which usually results in there readings being slightly lower than Matangi's.
I am not surprised that Hamilton's AWS temp is lower than Ruakura, but then again it shouldn't be used for Hamiltons readings. Ruakura would be much more representative. But then again Metservice doesn't want to use a NIWA station for there Highs for some reason.....

Their historic normals show that Ruakura generally has lower max-temps and higher min-temps than Hamilton Aero. So it seems a bit odd that, even though last year was NZ's 3rd warmest on record and Ruakura apparently completely smashed 9 of its previous average T-max and daily T-max records, Hamilton Aero (with a much shorter history) only beat 2 of them.

Comparing Ruakura's figures with Hamilton Aero's, and adjusting for comparative site anomalies, suggests that Ruakura's average T-max is currently running at about 1.7C higher than it should be relative to the airport, and has done ever since its last 'annual maintenance and calibration visit' in Nov 2012. In contrast, Ruakura's average T-mins last year look to be about 0.7C lower than they should've been. I've noticed other minor anomalies before and after calibration visits before, but this one really takes the cake.

As for the urban-heat-island (UHI) effect, I'm not so sure in Ruakura's case, as its normal average T-maxs relative to the airport's, tend to actually suggest a slightly cooler anomaly during the summer months. However, you'd really need to compare the wind and temp data from every day, of every month, over several years to get a clearer picture.

[melja]

And we trust these guys to tell us about climate change with all the dodgy warming going on in there figures.

[Manukau heads obs]

but thats why more than 1 stations data is used

[RWood]

but thats why more than 1 stations data is used

He's using one of the oldest fallacious arguments of "deniers" - none of whom seem to have heard of the Law of Large Numbers, unfortunately.