Tag Archives: Storm Weather

Storm Wild weather continues to wind its way

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Wild weather continues to wind its way

The rough weather that battered much of the New South Wales coast yesterday has continued, as emergency services brace for more calls for help.

http://www.abc.net.au/news/stories/2011/05/31/3231648.htm

Storm Weather Bureau warns region to brace for East Coast Low

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Weather Bureau warns region to brace for East Coast Low

The Weather Bureau is warning people living in southern parts of the region to brace for heavy rain and strong winds this afternoon.

http://www.abc.net.au/news/stories/2011/05/25/3226564.htm

Re: La ~ Nina and her effect on the Australian storm season / General weather

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March weather records for Blacktown

The month of March will conclude this topic.

During the month there were 9 days when the maximum temperature reached 30C taking the final tally to 59 for the season 1 October to 31 March. A near normal season occurred in terms of the number of 30C days. There were 2 thunderstorms with one occurring on 21 March which was weak and another on 30 March. It rained on 10 days but the final rainfall tally will not be known. The weather station at Collins Street Seven Hills quoted here so often appears to have malfunctioned on 19 March and was not operational until 1 April. However there were good rains during the period 19 March to 22 March following a dry start to the month.

The second table provides the number of thunderstorms experienced in my local area since 1998/1999 for the period 1 October to 31 March each year. When looking at the table it is hard to identify a trend. It seems that each season is different. The 1998/99 La Nina produced few thunderstorms for my local area but the 2007/08 La Nina produced many thunderstorms. During the 2010/11 La Nina period, there were 15 thunderstorms on 11 days but I noted that many storms were weak and had little adverse impact.

The tables referred to are provided below. Table one provides the monthly records for Blacktown and Table 2 provides the number of thunderstorms experienced in my local area commencing with the 1998/1999 season. Each season is from 1 October to 31 March. Some additional comments are provided below each table.

Harley Pearman

Storm Wild weather keeps SES busy

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Wild weather keeps SES busy

The SES has responded to 110 calls in the Illawarra and South Coast as wild weather batters the area.

http://www.abc.net.au/news/stories/2011/03/20/3168779.htm

Re: La ~ Nina and her effect on the Australian storm season / General weather

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Final effect of La Nina – Summer rainfall anomaly

I have produced on the Water and the Land site, the rainfall anomaly plot for the whole of Australia. Of note worthy significance is the area around Sydney / Newcastle / Wollongong / Lower Hunter and Lower North Coast. Well below average rainfall has occurred in this area for the period 1 December 2010 to 28 February 2011. The anomalies or below average rainfall is the worst in Australia. While the rest of Australia has had rain from this La Nina event, this area is suffering well below average rainfalls during the period. The plot is shown below.

This area really needs some rain and it is dry. The grass has dried right out and the region is rather brown from what I have seen from the lack of rain of recent weeks / months.

Harley Pearman

Re: La ~ Nina and her effect on the Australian storm season / General weather

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La Nina rainfall my my local area

As suggested, I would need to compare other La Nina's for my local area to see what has happened. I have managed to locate old rainfall data going back to 1950 for the Collins Street Weather Station at Seven Hills. Data started here on 1 January 1950. There is nothing before that. I have used that to compile some rainfall for the period September to March but only for the known La Nina years since 1950 that I am aware of. Prior to that, I cannot find anything.

However the Prospect Weather Station has rainfall records going back to January 1877. I found some rainfall records for the 1917/18 La Nina period as well for that station.

I also found daily temperature records for Prospect going back to about 1976.

I cannot find records of the number of thunderstorms.

I have presented 3 tables. One is for rainfall during La Nina periods September to March for my nearest weather station since 1950 being Collins Street, Seven Hills. This is for the La Nina's that I am aware of. One is for rainfall for the La Nina periods of 1910 and 1916/18 from the Prospect Weather Station. There appears to have been a La Nina around about 1917/18 and the third one is for the number of 30C days for the La Nina years 1983/84, 1989/90 as well as the most recent ones. I have used the Prospect station for this so there are minor variations.

I have discovered that a dry January and February has occurred before during a La Nina year for Blacktown (January and February 1965). I have discovered that La Nina's can bring very wet summers but also drier summers (The comparison of the wet summer of 1955/56 to the dry summer of 1964/65 is amazing). It appears on the whole that a La Nina does bring a wetter spring / summer period overall but occasionally, it can be drier. So far the rainfall for this La Nina 2010/11 is much lower than that of recent and previous La Nina's (September to March period).

When comparing the number of 30C days during La Nina periods (September to March) at least from 1983/84, there seems to be a reduction in number of very hot days although I have found that it reached 42C on 3/1/1990. It reached 40C three times this summer just gone at Blacktown.

It seems that this summer 2010/2011 for Blacktown has been quite reasonable and not too wet.

I found the data from the Bureau of Meteorology site "Water and the Land" in climate data. The tables referred to are provided below.

Harley Pearman