NZ/Aust Weather Comparisons

janewaystv · Unread post by **janewaystv** » Mon 31/07/2006 18:08

Sorry about delay-busy with things etc.

I can do that, but u would have to wait a few weeks or a month at the most, as i have them on paper (given to me by BOM) and have to put the data into my PC onto the spreadsheets, which i havent done yet, will try and do as much as i can depending on free time.

Thanks for the Wellington info-interesting reading

RWood · Unread post by **RWood** » Mon 31/07/2006 18:19

No problem, plenty of time

.

The application - for simplicity, as it processes several types of numbers, uses whole-number values. If your data turns out to include decimals, I have a tricky method of creating rounded values from them in such a way that annual totals and column-totals for months are accurate to within 0.6 (by sometimes rounding .4 items upwards and/or .6 items downwards - clear as mud, yes...).

I can give you some other Kelburn data in graphs later...probably best to do that from time to time, something to look forward to.

Andy · Unread post by **Andy** » Mon 31/07/2006 18:42

1964 as you said before was very dry in NZ SI esp Alexandra (167mm or something like that), that reminds me of SA which is the driest state in Oz. Its very remarkable that Alexandra can record so little rain yet just over the mountains (Westland/Fiordland) they can record much, much more rain, I think its amazing, u know what I mean?

RWood do you have the monthly rainfall totals for that year? Any other interesting South Island weather stats would be good as well.

RWood · Unread post by **RWood** » Mon 31/07/2006 19:17

I have them in the old inches and 1/100ths:

Starting with Nov 1963:
11/63 0.47 12/63 0.52
1/64 0.51 (3 cool dry windy months to start with)
2/64 0.09 (very warm) 3/64 2.09
4/64 0.72 5/64 1.01
6/64 0.09 (dull, many fogs) 7/64 0.22 (v mild)
8/64 0.30 9/64 0.31
10/64 0.26 11/64 1.06
12/64 1.63

Total 11/63 - 10/64 6.59" (NZ record low for 12 months)
Total 1964 8.29" (NZ record low annual total)

1965 broke the spell with a warm, cloudy month in Alex with double average rain - the annual total was well above average, as in most of the South Island.

I could send later a graph of Alex rainfall 1922-1999 (NIWA had a break in site reporting or maintenance and it's difficult to get data from after then - need other sources).

Andy · Unread post by **Andy** » Mon 31/07/2006 20:05

Hey thank you.

It would be great to see that graph.

A dry year so far in Alex only 113mm, with 5 months left.

RWood · Unread post by **RWood** » Mon 31/07/2006 20:21

Here it is, in 2 parts - will try to get both in the same post. Numbers in whole mm - August 1948 rounded down to zero. You can get more data for a "bar" in the Excel view by moving the cursor over it. Graphs centred around the mean values.

Contrary to what many imagine, quite a number of the high-reading months coincide with higher than average values "over the hill" in Milford.

Happy browsing!

Andy · Unread post by **Andy** » Tue 01/08/2006 07:56

Great, thanks again.

RWood · Unread post by **RWood** » Tue 01/08/2006 08:32

janewaystv wrote:1964 in Syd was remarkable for 4th wettest June with 408mm, and 13th driest July with 10mm.

To veer off a little - here's graphs of monthly/annual MSLPs for Wellington, 1911-2004. Gives you an idea of what was going on in the middle parts of the country, at least. It's not all obvious from the annual values, but notable are:

July 1939 - June 1940 - lowest 12-month average (was in an El Nino)

1950 - high values - strong La Nina boosted them (May 1950 thru Mar 1951 are high)

Highest 12-month was from Aug 1966 - July 1967 (W'gton's overall weather in this period was nothing specially good, included its cloudiest August and a very poor December)

Highest annual in 1999 - NZ overall had its highest ever values that year.

Units are a bit confusing - monthly values are in hPa/10, excess over 1000 (so 1010.2 would be 102) - annual is just the sum of the monthly values. Annual average equates to about 1014.2 hPa.

janewaystv · Unread post by **janewaystv** » Tue 01/08/2006 20:14

Rwood-need some help please-re Alexandra/Wellington data.

Example Jan Stat

6-driest
129-wettest
42.9615.....Mean Rainfall
10
2
4
2
78- What does those numbers stand for? (the last 5 numbers)??

Thanks

RWood · Unread post by **RWood** » Tue 01/08/2006 22:44

Those last 5 numbers are "working numbers" related to the construction of the graph. I have a piece of code in the original (Access) database which decides how to scale the graph. [All the real data is in the "bars" or the rest of the raw data.] The Access database application writes the "working" values in the spreadsheet, where a recorded VB macro uses them to define graph parameters. In the case of Alex. rainfall, January:

10 = distance beween major tickmarks and gridlines ,vertical (value) axis (6,16,26,etc)
2 = distance between minor tickmarks, vertical axis (there's a tick for every increase of 2 in value)

4 = spacing of label values, horizontal (category) axis (which is years) - 22,26 etc
2 = spacing of (major) gridlines, horiz. axis - here at 23/24, 25/26, etc.

78 = number of observation years (values on horiz. axis)

In some graphs this last spacing number doesn't divide into the label spacing value.

I'm a bit rusty on the names of these Excel graph parameters - they're not easy to remember, so when you've worked out how you want to control a graph, the VB macro recording saves future thinking. I devised the formulae, and my partner (who has been programming in various languages for many years) wrote the base code, which I then fiddled around with a bit till I stop changing my mind. The graphing thing is just one of the things the database code can do - there are a few customised reports as well.

janewaystv · Unread post by **janewaystv** » Wed 02/08/2006 15:01

Thanks Rwood

. I get it now. I might be asking too much, but would it be possible one day to put Invercargills data on as well, if u dont mind?

Have started on the data-entry for Sydneys sunshine data, have however noticed some errors made by BOM-ie hours dont actually add up to the right amount esp for annual ones, but I will still put them in regardless if youre happy with that? or I can add them up myself?

RWood · Unread post by **RWood** » Wed 02/08/2006 15:19

I'd be more than happy to forward the Invercargill graphs for sunshine - I have all the values back to 1932 (as they originally appeared in "Met Obs" up to 1987, and by direct request to NIWA for later years to 2004 - I wait about 12 months for late returns or corrections for a given year, so won't go after 2005's until about December). {Pre-1932 data from there is not regarded as being very reliable, and I no longer have it.}

It's very easy to generate the graphs from the application - the only annoyance is the 80KB limit for this forum which means splitting bigger workbooks.

For rainfall, I only have database records for a small handful of locations
- not including In'gill. [There is printed data - not necessarily complete or post-validated - in my "Climate Digest" copies, but that would be slow and tedious to look up and transcribe].

For Sydney records - you could leave out the totals if you like - the application just adds up the monthly totals to gte the annual values anyway.

RWood · Unread post by **RWood** » Wed 02/08/2006 22:01

Here's the Invercargill data. You may notice small differences (should not be more than about 1 hr) in monthly totals - can't remember now what kind of rounding trick I used to preserve totals (the source data prior to 1956 was given in hrs and 10ths).

Having seen some summary data for June in the Digest, I can confirm that In'gill didn't quite set a record (can't disclose information until much "later").

Weathermad · Unread post by **Weathermad** » Thu 03/08/2006 07:35

Fascinating reading with all the statistics ...great...thanks!

I remember living in Dunedin and in June 1977, there was quite a long period of gloom and drizzle and I remember a test the All Blacks played at Carisbrook at the time and sports commentator Keith Quinn said 'No Dunedinites its not a UFO, its the sun for the first time in 10 days!'

RWood · Unread post by **RWood** » Thu 03/08/2006 08:29

Happy to provide someone interest and pleasure - most people I know couldn't care less about such things (though they might demand explanations of the whats/whys of weather!

)

Yes, between a sunny early part of autumn and sunny late spring 1977 there was a long run of wet dull months in a lot of places in the east from Southland thru' to Wairarapa, plus Wellington/Horowhenua/Manawatu. Things got very soggy - overall it was described as a "cold wet year in places exposed to the east and south". July sun was at record lows in Otago & Canterbury, except in MacKenzie. Wellington had its wettest year ever, and its dullest winter.

BUT things later rolled on into the great 1977-1978 summer that Michael remembers!

janewaystv · Unread post by **janewaystv** » Thu 03/08/2006 11:32

Thanks Rwood for the Ivc ones-quite a sudden decline in sunshine hours from Feb-Jul and a rapid increase from Aug-Jan especially in some years. Sunshine doesnt increase by seasons/warmer months, its just happens, which i find a bit odd, as in Sydney, mainly sunshine increases toward the warmer months and decreases towards the colder months. Interesting.

The sunshine hours seem similar to that of the UK.

RWood · Unread post by **RWood** » Thu 03/08/2006 12:05

Yes, as I commented in a post a few months back In'gill (and probably a coastal strip of the area to go with it) has a unique pattern - but then that same post pointed out the seasonal variations in the South Island are interesting - in the NI they are rather ho-hum. The development of an upper-atmospheric ridge over the SI is supposed to explain why most of it
is brighter and drier in late winter than would otherwise be expected. But these things vary a lot over longer timespans. People on this site talk about August storms, but in the 1950s there were some very settled Augusts, culminating in 1960.

The autumn decline in sun in In'gill was particularly noticeable when I lived there - but in recent years March, April and June have improved while May might now be following suit. The May graph shows definite phases - in the 50s it was relatively sunnier than April, that suddenly reversed in the 60s and 70s. Also the cloudier epoch 1961-1987 (annual values) stands out - I can recall a sudden change in weather regime about 20th Dec 1960 from a benign spring and a cool but bright start to Dec, to much more unsettled conditions.

For the data to 2004 In'gill's monthly %ages of possible are:

40.5 42.4 38.2 34.6 31.3 29.7 35.5 40.1 41.1 40.6 40.5 40.4

Annual 38.5%

The attached workbook is some older data I collated - there are a lot of ifs and buts about reliability of data, accuracy or currency of "horizon profiles", etc., but if gives you a notion of what I'm referring to, esp. re the South Island. In the end a comment by a Met. scientist who published one of the 30-year means tables (in the days when they printed hardcopy!) applies - "the NZ sunshine data shows variations in time and space for which the data do not provide the answers" (this conclusion after analysing various anomalies and explaining some of them)

RWood · Unread post by **RWood** » Thu 03/08/2006 13:10

As a final bit of data for the site I can show you a couple of reports from the database:

janewaystv · Unread post by **janewaystv** » Thu 03/08/2006 14:52

Thanks Rwood.

Am halfway with the Sydney sunshine data, however some notes to remember, sunshine recording started at Observatory Hill in Jan 1931 and it closed at the end of 1991, then from 1992 onwards from Sydney Airport, so there will be some differences that you will notice as Sydney Airport is more sunnier than at Observatory Hill.

janewaystv · Unread post by **janewaystv** » Thu 03/08/2006 15:03

Got the Oz July 2006 temp Statistics in today.

Syd City-avge max of 17.9oC, nearly 2oC above avge, however given that it is on average 1oC cooler in July than in June then its rather strange to note that June had an avge max of 16.9oC, making July 1oC warmer than June.

Brisbane and Melbourne followed similar trends.

The avge max in June for Brisbane was 21.8oC (0.9oC above avge) while July had avge max of 22.5oC, which was 2oC above avge.

Melbourne's trend wasnt as strong with June avge max being 14.3oC (0.3oC above avge) and July recording a avge max of 14.5oC which was 1.1oC above avge.

Other cities Oz-wide also recorded similar trends with Newcastle (17.7oC for June and 17.9oC for July), Wollongong with 16.6oC for June and 17.1oC for July and Canberra with 11.9oC for June and 12.7oC in July.

A lack of cold air during July was responsible for the warmer temps along with some persistant and slow-moving bands of N winds.

RWood · Unread post by **RWood** » Thu 03/08/2006 15:10

Tends to be a common issue - in Auckland there have been several site changes, making longterm analysis tricky. In Sydney's case the most helpful thing would be to have another site with reasonably long records as a comparison - looks like Williamtown with 47-odd years' records to 2004 is a reasonable prospect. But in any event the composite data should be very interesting...

RWood · Unread post by **RWood** » Thu 03/08/2006 16:19

janewaystv wrote:Got the Oz July 2006 temp Statistics in today.

Syd City-avge max of 17.9oC, nearly 2oC above avge, however given that it is on average 1oC cooler in July than in June then its rather strange to note that June had an avge max of 16.9oC, making July 1oC warmer than June.

Brisbane and Melbourne followed similar trends.

The avge max in June for Brisbane was 21.8oC (0.9oC above avge) while July had avge max of 22.5oC, which was 2oC above avge.

Melbourne's trend wasnt as strong with June avge max being 14.3oC (0.3oC above avge) and July recording a avge max of 14.5oC which was 1.1oC above avge.

Other cities Oz-wide also recorded similar trends with Newcastle (17.7oC for June and 17.9oC for July), Wollongong with 16.6oC for June and 17.1oC for July and Canberra with 11.9oC for June and 12.7oC in July.

A lack of cold air during July was responsible for the warmer temps along with some persistant and slow-moving bands of N winds.

See NZ NIWA summary post. Similar in NZ - July temps. above average (a little), and warmer than June - happens 1 year in 5. Auckland sunniest main centre in June (N Plymouth had even better totals for both months). Despite high rainfall, Wellington also sunnier than usual.

Weathermad · Unread post by **Weathermad** » Fri 04/08/2006 07:35

Great discussion you two!

RWood, I also lived in Southland in both Invercargill and Gore for a number of years.

Is Gore slightly more sheltered from the westerlies, therefore a little sunnier than its coastal neighbour?

Interestingly enough I believe Gore has the highest total nationally for sunshine over one day at over 15 hours (must have been a sunny summers day where the sun shines until 10pm basically) but I also recall near records for sunless days, if not weeks!

I remember the town for its very severe frosts and its occasional snowy days during winter whereas with Invercargill, I'll never forget biking to school in the winter and spring months and being pounded by horizontal rain and a severe westerly gale...It was murder heading home into it!

Janewaystv...I spent a little time in Brisbane over the winter and wondered if July was somewhat warmer than usual and your statistics proved that, thanks...There was one night early in the month in Caloundra on the Sunshine Coast where it rained off and on but the low was 19 degrees...ooohhh those were the days!!

Are frosts ever recorded in Sydney?...and if so, whereabouts exactly....Is it more likely in the western suburbs of Sydney?

Andy · Unread post by **Andy** » Fri 04/08/2006 08:03

Yea great reading. Cheers for the info and stats - KEEP IT Coming !

RWood · Unread post by **RWood** » Fri 04/08/2006 08:21

Weathermad wrote:Great discussion you two!

RWood, I also lived in Southland in both Invercargill and Gore for a number of years.

Is Gore slightly more sheltered from the westerlies, therefore a little sunnier than its coastal neighbour?

Interestingly enough I believe Gore has the highest total nationally for sunshine over one day at over 15 hours (must have been a sunny summers day where the sun shines until 10pm basically) but I also recall near records for sunless days, if not weeks!

I remember the town for its very severe frosts and its occasional snowy days during winter whereas with Invercargill, I'll never forget biking to school in the winter and spring months and being pounded by horizontal rain and a severe westerly gale...It was murder heading home into it!

Janewaystv...I spent a little time in Brisbane over the winter and wondered if July was somewhat warmer than usual and your statistics proved that, thanks...There was one night early in the month in Caloundra on the Sunshine Coast where it rained off and on but the low was 19 degrees...ooohhh those were the days!!

Are frosts ever recorded in Sydney?...and if so, whereabouts exactly....Is it more likely in the western suburbs of Sydney?

Gore has about 150mm less rain per year than Ivc. From older records, there's not much difference in the sun - Gore about 40-60 hrs more/year, though I suspect its sites were disadvantaged slightly in terms of measurable hours. Its total in April 1965 was only 52 hrs. There are no sites in the area at present for comparison purposes. I can recall a story from many years back about the most sunshine in a day - that may have been surpassed by now - I think it was Dec. 1954!

I did the "bike thing" for a number of years. The year when the westerlies were most absent (1960) came a bit late as my biking had almost ceased!
The most powerful westerly I recall didn't come with rain - just a straight W howling up Tay St on the evening of 31 May 1958 (a very deep low was passing just to the south).

I'm already starting to forget the evenings in Brazil when it didn't drop below 19 (Rio) or 22 (Salvador)