Surf forecast issued Thursday 3 February 2011:
Seven day outlook for Sydney:
Small to medium Noreast windswell (not from TC Yasi), followed by wind driven South swell after a southerly change late Sunday morning.
Friday: in the 1-2 metre range East North East (N wind).
Saturday: in the 1-2 metre range North East (NE wind).
Sunday: about 1 metre or so North East at first, coming up a bit from a southerly change so windblown.
Monday: in the 1-2 metre range South East (with wind).
Tuesday: ditto.
Wednesday: bit bigger from the East South East, maybe around 2 metres.
Thursday: back down in the 1-2 metre range East South east
Water temp is around 24 -25.
TC Yasi
Despite being a category 5 Tropical Cyclone thankfully there has been no loss of life reported to date. Hopefully that will continue to be the case.
The Bureau of Meteorology website which has an excellent section on Tropical Cyclones..
http://www.bom.gov.au/cyclone/about/
http://www.bom.gov.au/cyclone/faq/index.shtml#definitions
Also from the BoM website, here’s a map showing areas of Australia subject to Tropical Cyclones…
http://www.bom.gov.au/cgi-bin/silo/cyclones.cgi?®ion=aus&syear=1908&eyear=2005
While Sydney and NSW generally do not get tropical cyclones, we do have East Coast Low pressure systems which at times can produce similar impacts to tropical cyclones – eg May 1974 storm wind gusts of 165 km /hr on the Northern Beaches (and Newcastle) – which I remember so well when the neighbour’s roof landed on mine in the middle of the night – would be similar to a category 3 tropical cyclone.
http://www.bom.gov.au/nsw/sevwx/facts/ecl.shtml
Given that Tropical Cyclones are erratic in their movement, the fact that the Bureau could forecast TC Yasi’s track in advance so well is amazing to this lay person… Detailed storm/ cyclone tracking forecast maps were only introduced on the Bureau’s website a few years ago
http://www.bom.gov.au/products/IDQ65002.shtml
Clearly that forecasting capability and resultant warnings, people heading the warnings and taking precautions has saved lives.
Damage to property appears to have been minimised as, learning from past cyclones, new buildings in known cyclone prone areas have been constructed to cyclone standards – older buildings in cyclone areas – ie all of Queensland – can’t be expected to be unaffected.
The advances that have been made in weather forecasting in recent years are worth noting.
Bear in mind that we now take 7 day weather forecasts for granted, for a part of the world that is subject to constantly changing, highly variable weather.
Less than 10 years ago the best they were confident with were 3 day forecasts.
In the 1950s the Sydney daily newspapers gave you a general weather forecast for that day!
http://trove.nla.gov.au/ndp/del/page/1033371
Check out the “forecast” on top left of the front page of the SMH for Friday 3 February 1950 (from National Library of Australia website). There’s also a “weather report” on page 4, which tells you what yesterday’s ! temperatures were. No weather map that day – maybe they missed the print deadline? Here’s the weather map and report in Thursday’s paper…
http://trove.nla.gov.au/ndp/del/page/1033357?zoomLevel=2
TC Yasi’s overall size was highlighted in regularly updated satellite photos in news media.
10-15 years ago you wouldn’t have been able to see such satellite photos!
TC Tracy hit Darwin in December 1974 – ‘virtually without warning’…
Today’s weather/cyclone forecasting capability certainly is far better than back then.
For the future, here is the Bureau of Meteorology’s current assessment:
Trends in tropical cyclone activity in the Australian region (south of equator; 105-160 E) show that the total number of cyclones has decreased in recent decades. However, the number of stronger cyclones (minimum central pressure less than 970 hPa) has not declined.
This overall decrease may partly be due to an improved discrimination between tropical cyclones and sub-cyclone intensity tropical lows. Tropical cyclone numbers in the Australian region are influenced by the El Nino-Southern Oscillation phenomenon and the decrease in total cyclone numbers may be associated with an increased frequency of El Nino events. A number of long-term trends and oscillations have been observed in other parts of the world, extending over many decades. It is difficult to sort these natural trends from those that may result from global warming.
Potential changes in tropical cyclone occurrence and intensity are discussed in detail in the 2007 report, Climate Change in Australia Technical Report – Chapter 5: Regional climate change projections (8.9MB) See: Chapter 5.9.1 Severe weather: Tropical cyclones. There have been three recent studies producing projections for tropical cyclone changes in the Australian region. Two suggest that there will be no significant change in tropical cyclone numbers off the east coast of Australia to the middle of the 21st century. The third study, based on the CSIRO simulations, shows a significant decrease in tropical cyclone numbers for the Australian region especially off the coastline of Western Australia. The simulations also show more long-lived eastern Australian tropical cyclones although one study showed a decrease in long-lived cyclones off the Western Australian coast.
Each of the above studies finds a marked increase in the severe Category 3-5 storms. Some also reported a poleward extension of tropical cyclone tracks.
Projected changes in tropical cyclone characteristics are inherently tied to changes in large-scale teleconnection patterns such as ENSO, changes in sea surface temperature and changes in deep convection. As global climate models improve, their simulation of tropical cyclones is expected to improve, thus providing greater certainty in projections of tropical cyclone changes in a warmer world.”
Now, today’s Weather from the Bureau:
Forecast for the rest of Thursday
Summary
Possible shower.
Chance of any rain: 30%
Metropolitan area
Partly cloudy at times. Isolated showers and the chance of thunderstorms. Winds south to southwesterly averaging 15 to 25 km/h becoming southerly up to 20 km/h later in the evening.
Friday 4 February
Summary
Min 24
Max 33
Possible shower.
Chance of any rain: 40%
Rainfall amount: 0 to 2 mm
Metropolitan area
Partly cloudy. The chance of showers until evening. The chance of thunderstorms in the afternoon and evening, mainly in the west. Winds south to southeasterly averaging up to 20 km/h tending north to northeasterly during the morning.
Fire Danger – High
UV Alert from 9:10 am to 5:10 pm, UV Index predicted to reach 13 [Extreme]
| Around Sydney | ||
| Location | Min | Max |
| Sydney | 24 | 33 |
| Penrith | 23 | 38 |
| Liverpool | 22 | 36 |
| Terrey Hills | 22 | 33 |
| Richmond | 23 | 37 |
| Parramatta | 22 | 36 |
| Campbelltown | 21 | 34 |
| Bondi | 24 | 29 |
Saturday 5 February
Summary
Min 25
Max 36
Mostly sunny.
Metropolitan area
Partly cloudy. Winds northerly averaging up to 20 km/h tending northwesterly up to 30 km/h during the morning.
Sunday 6 February
Summary
Min 24
Max 31
Few showers.
Metropolitan area
Cloudy. Scattered showers and isolated thunderstorms. Winds west to northwesterly averaging 10 to 20 km/h ahead of a cooler south to southeasterly change up to 40 km/h during the late morning or early afternoon.
Monday 7 February
Summary
Min 20
Max 23
Shower or two.
Metropolitan area
Cloudy. Isolated showers. Winds south to southeasterly averaging up to 30 km/h tending southeasterly and light during the afternoon.
Tuesday 8 February
Summary
Min 20
Max 24
Shower or two.
Metropolitan area
Cloudy. Isolated showers. Light winds tending east to southeasterly up to 20 km/h during the afternoon.
Wednesday 9 February
Summary
Min 20
Max 23
Shower or two.
Metropolitan area
Cloudy. Isolated showers. Winds south to southeasterly averaging up to 30 km/h.
Thursday 10 February
Summary
Min 20
Max 25
Possible shower.
Metropolitan area
Cloudy. The chance of showers. Winds south to southeasterly averaging up to 20 km/h increasing to up to 30 km/h during the morning.
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And a bonus add on from The Goat…
(Last Posted by: goat on January 30th, 2009)
Yesterday’s max for Sydney was 41… following on from several uncomfortably hot, humid days and nights… It’s now much cooler after the Southerly change came through today.
It’s that time of year. Just for info, the following observations of Sydney’s climate were written at the time of first European settlement…
Watkin Tench 1793:
“….Horticulture has been attended in some places with tolerable success… Nor will this surprise, if the genial influence of the climate be considered. Placed in a latitude where the beams of the sun in the dreariest season are sufficiently powerful for many hours of the day to dispense warmth and nutrition, the progress of vegetation never is at a stand. The different temperatures of Rose Hill (near Parramatta) and Sydney in winter, though only twelve miles apart, afford, however, curious matter of speculation.
… Again, the heats of summer are more violent at the former place than at the latter, and the variations incomparably quicker. The thermometer has been known to alter at Rose Hill, in the course of nine hours, more than 50 degrees (Fahrenheit = 10 degrees Celsius) ; standing a little before sunrise at 50 degrees, and between one and two at more than 100 degrees (= 38 degrees Celsius). To convey an idea of the climate in summer, I shall transcribe from my meteorological journal, accounts of two particular days which were the hottest we ever suffered under at Sydney.
…December 27th 1790. Wind NNW; it felt like the blast of a heated oven, and in proportion as it increased the heat was found to be more intense, the sky hazy, the sun gleaming through at intervals.
At 9 a.m. 85 degrees. At noon 104. Half past twelve 107 ½. From one p.m. until 20 minutes past two 108 ½. At 20 minutes past two 109 (= 42 degrees Celsius). At Sunset 89. At 11 p.m. 78 1/2
[By a large Thermometer made by Ramsden, and graduated on Fahrenheits scale.]
December 28th 1790.
At 8 a.m. 86 10 a.m. 93 11 a.m. 101 At noon 103 1/2 Half an hour past noon 104 1/2 At one p.m. 102 At 5 p.m. 73 At sunset 69 1/2
[At a quarter past one, it stood at only 89 degrees, having, from a sudden shift of wind, fallen 13 degrees in 15 minutes.]
My observations on this extreme heat, succeeded by so rapid a change, were that of all animals, man seemed to bear it best. Our dogs, pigs and fowls, lay panting in the shade, or were rushing into the water.
But even this heat was judged to be far exceeded in the latter end of the following February, when the north-west wind again set in, and blew with great violence for three days. At Sydney, it fell short by one degree of what I have just recorded: but at Rose Hill, it was allowed, by every person, to surpass all that they had before felt, either there or in any other part of the world. Unluckily they had no thermometer to ascertain its precise height. It must, however, have been intense, from the effects it produced. An immense flight of bats driven before the wind, covered all the trees around the settlement, whence they every moment dropped dead or in a dying state, unable longer to endure the burning state of the atmosphere. Nor did the perroquettes, though tropical birds, bear it better. The ground was strewn with them in the same condition as the bats.
Were I asked the cause of this intolerable heat, I should not hesitate to pronounce that it was occasioned by the wind blowing over immense deserts, which, I doubt not, exist in a north-west direction from Port Jackson, and not from fires kindled by the natives. This remark I feel necessary, as there were methods used by some persons in the colony, both for estimating the degree of heat and for ascertaining the cause of its production, which I deem equally unfair and unphilosophical. The thermometer, whence my observations were constantly made, was hung in the open air in a southern aspect, never reached by the rays of the sun, at the distance of several feet above the ground.
My other remarks on the climate will be short. It is changeable beyond any other I ever heard of; but no phenomena sufficiently accurate to reckon upon, are found to indicate the approach of alteration. Indeed, for the first eighteen months that we lived in the country, changes were supposed to take place more commonly at the quartering of the moon than at other times. But lunar empire afterwards lost its credit. For the last two years and a half of our residing at Port Jackson, its influence was unperceived. Three days together seldom passed without a necessity occurring for lighting a fire in an evening. A habit dete, or a habit de demi saison, would be in the highest degree absurd. Clouds, storms and sunshine pass in rapid succession. Of rain, we found in general not a sufficiency, but torrents of water sometimes fall. Thunder storms, in summer, are common and very tremendous, but they have ceased to alarm, from rarely causing mischief. Sometimes they happen in winter. I have often seen large hailstones fall. Frequent strong breezes from the westward purge the air. These are almost invariably attended with a hard clear sky. The easterly winds, by setting in from the sea, bring thick weather and rain, except in summer, when they become regular sea-breezes.
To sum up: notwithstanding the inconveniences which I have enumerated, I will venture to assert in few words, that no climate hitherto known is more generally salubrious, or affords more days on which those pleasures which depend on the state of the atmosphere can be enjoyed, than that of New South Wales. The winter season is particularly delightful.
Extract from A Complete Account of the Settlement at Port Jackson, in New South Wales, Including an Accurate Description of the Situation of the Colony; and of its Natural Productions; Taken on the Spot (London, 1793; German and Swedish translations) Watkin Tench.
