Discussion: Sydney's Weather

[rainfan]

Originally Posted by ATO2

That drought issue is quite something, for sure.Forgive my ignorance, but how does NSW situation compare with the other States?

Eastern & Northern NSW is doing ok for now.

Western/southern areas of NSW as well as southern WA, SA, VIC bar Gippsland, ACT and N & W Tasmania are the ones doing it really tough at the moment.

In some of those areas rainfalls have not exceeded the average in 11-12 years. What's remarkable about this is the length/severity of the drought & how it's been affecting coastal areas rather than just inland. Since 2000 many areas of Australia have seen much less rain than "more" of with the latter being too rare.

Outside the NT - Sydney has consistently been the wettest state capital over the past few years. 2007 at Ob Hill had 1500mm - probably around 900mm - 1000mm more than other state capitals.

Australia has suffered extreme/serious droughts at various times over the past 100 years. Three such outstanding examples:- 1895-1902 "Federation", 1982-1983 "El Nino" and 2002-2003 "Millennium"

[rainfan]

Originally Posted by RWood

The "rain concern" zone here has shifted to the southern lake catchments (for hydro) - other areas have recovered though parts of the eastern SI are fairly dry still.

Didn't this also occur during the early 1990's? Looks like history's repeating itself. Wouldn't be a particularly great time to have power rationing with winter just around the corner...at least for now temps aren't too cold.

[RWood]

Yes, in 1992. But 1992 was worse, one of the reasons being prolonged coldness (cold autumn, average winter, cold spring).

Re Aus. droughts - those crazies on Weatherzone just won't admit that there could be some longterm changes afoot in Aus. They have also banned the only technical expert from their antiwarming threads - they are I'm afraid stupid, and paranoid about the wrong things!

[ATO2]

Originally Posted by RWood

Yes, in 1992. But 1992 was worse, one of the reasons being prolonged coldness (cold autumn, average winter, cold spring).

We were farming in 1992. It was not nice. Also, wasn't that the year after a volcanic eruption in SE Asia -Mt Pinatubo- was it?

[RWood]

Yes, Pinatubo was the main driver though independent El Nino phases helped as well. Apart from the coldness things were not quite one-sided with the weather - parts of the South Island were relatively dry with normal sun, but the rest of the SI was cloudy. In the North Island it was easily the cloudiest year on record - which I found much more depressing than the coldness, but oddly this was almost entirely due to the last 4 months, which had massive deficits. The lack of even a single month with above-normal sun in the NI during the first 8 months did not compensate for that. Many places had lowest-ever annual totals in the NI.

[rainfan]

Weather for Saturday 17 May:
Sunny start at first with high cloud increasing during the morning becoming overcast with mild N-NW winds gusty at times changing to gale, colder W-SW winds after 5pm with some light patches of rain at times then clearing well after dark.
Went out to dinner last night in my suburb and the wind was very icy blowing into my face making my eyes sting/water painfully by the time got back home.
Min of 15oC and top of 21oC before the change, after the change temps dropped to 11oC in the space of 1.5 hours.

Sunday 18th May:
7.30am update: Overcast with very cold SW winds blowing, currently 8oC.

[ATO2]

Originally Posted by rainfan

Sunday 18th May:
7.30am update: Overcast with very cold SW winds blowing, currently 8oC.

I was thinking about the rainfall you mentioned for Sydney...On our TV weather maps, for a long time it has seemed to show up as having had, or about to rain, more often than I would have expected. Does that plentiful rainfall extend into the Blue Mountains?

[rainfan]

Originally Posted by RWood

Yes, in 1992. But 1992 was worse, one of the reasons being prolonged coldness (cold autumn, average winter, cold spring).

Re Aus. droughts - those crazies on Weatherzone just won't admit that there could be some longterm changes afoot in Aus. They have also banned the only technical expert from their antiwarming threads - they are I'm afraid stupid, and paranoid about the wrong things!

Ah yes. There have been numerous attacks on Sydney by several Victorians for "hogging" the rain which is just plain ridiculous . I can understand Victorian's frustrations but there's no need to take it out on Sydneysiders, I know of a rather large number of Sydneysiders who have left WZ as they were fed up with the attacks and as put by an ex-member being overtaken by "Victorians"

I think it could be better termed as "natural climate change" rather than drought as it's been ongoing for 11-12 years. The "averages" for those areas certainly need revising.

[rainfan]

Originally Posted by ATO2

I was thinking about the rainfall you mentioned for Sydney...On our TV weather maps, for a long time it has seemed to show up as having had, or about to rain, more often than I would have expected. Does that plentiful rainfall extend into the Blue Mountains?

Monthly/Annual rainfall totals expressed as percentages of the average for Ob Hill Sydney.

Jan 07: 44.1%
Feb 07: 92.0%
Mar 07: 50.1%
Apr 07: 142.4%
May 07: 8.0%
Jun 07: 390.9%
Jul 07: 68.8%
Aug 07: 185.8%
Sep 07: 59.3%
Oct 07: 34.9%
Nov 07: 204.8%
Dec 07: 158.5%
2007 Total: 123.3%

Jan 08: 55.4%
Feb 08: 221.0%
Mar 08: 48.6%
Apr 08: 116.2%

As you can see rainfall varies greatly from month to month (May 07's 8% to June's 390.9% is an such example).

Sometimes there'll be forecast of rain which doesn't eventuate, on the other hand a expected fine and sunny day will end up being very wet and cloudy as happened in August 2004. On the forecast "fine & sunny" day - 105mm fell accompained by a southerly gale.

There is a trend for "less" rain as you head inland from the coastal strip. The Blue Mountains being right out W on the edge of the whole metro area usually misses out on rain coming in from the S-SE. If there are E-NE as well as strong ECL patterns then the BMA do very well.

May 2001 was a S-SE month with 371mm falling at Ob Hill, yet at Liverpool in the SW only 66mm fell & 33mm at Penrith which is right next to the Blue Mountains area.

[ATO2]

Thanks, ranfan. The figures are quite fascinating: a little then a lot!
Another query- without going too much outside the thread- where does Sydney source its water supply?