Australian Severe Weather Forum

Warmer than normal spring expected for 2009

I have been looking at and plotting likely temperature anomalies using the new CSIRO POAMA (Predictive Ocean Atmospheric Model for Australia) program for the months of September, October and November. This tool while still in the experimental stage has been made available for research purposes for predicting rainfall and temperature patterns for Australia and it is still being tested. When generating temperature plots for September to November it appears that a warmer than normal spring is likely. In particular for New South Wales:-

- The three month average seasonal maximum temperature anomaly is suggested as being 1.5C above average across the central and northern inland areas of the state and largely 0.5C to 1C above average elsewhere.

- The three month average seasonal minimum temperature anomaly is suggested as being 2C above the average for North East New South Wales and 1.5C above average elsewhere.

The POAMA plots (Computer program developed by the CSIRO) are set to the Hindcast dates 1980-2006 for average temperatures and Lead Times set to 1 Month, 2 Months and 3 Months being September, October and November with the day set to 01 being the first day of each month.

September - The model ensemble suggests that Eastern New South Wales will have maximum daytime temperatures of 1C above the average. The model ensemble suggests that North East New South Wales will have maximum daytime temperatures of up to 1.5C above the average.

October - The model ensemble suggests that large areas of the state will experience maximum daytime temperatures of up to 1C above the average. The model ensemble suggests that coastal areas will have maximum daytime temperatures of 0.5C to 1C above the average.

November - The model ensemble suggests that North East and Eastern New South Wales will have maximum daytime temperatures of up to 0.5C above the average.

The POAMA temperature plots as discussed above are attached below and feel free to describe any significant spring hot weather event that may occur.

Harley Pearman

If yesterdays late winter temperatures are anything to go by, QLD might just completely bypass spring and go straight to summer. SEQ temps after today, for the remaining week of  August, are that of late spring temps. A couple of cool nights are on the cards and then that is it for us. It appeared with May and June we were off to  a cold winter, then it just fizzled out then the heat came. So now we look forward to a warmer than normal Spring. ( probably hot for SEQ)  

Be intersting to see all the stats as you present them Harley. You do an excellent job with them,  and it helps me to gain an understanding what is happening statistically. Sometimes you hear people say "it seems it has beeen a hotter year", or a "wetter summer" etc etc etc, but to have the facts in front of you and to be able to say "yes or no" and able to explain "why", is brilliant! Thanks


Late Edit: Haydon Walkers prediction for SEQ Spring,

A long-range weather forecaster predicts a warm to hot spring in the south-east, and plenty of storm rains in November.

Forecaster Haydon Walker says he predicted the cyclones earlier this year but was not expecting yesterday's record winter temperatures.

Mr Walker says spring will see temperatures in the 30s.

"With the storm rains I'm predicting in November, it's going to be quiet sticky I think with the humidity factor, with some really good storm rains for the south-east in that period building from October into November," he said.

"With the humidity I think it's going to be quiet sticky and uncomfortable."


Col

Edit JD: For those who are not aware, Haydon Walker uses the sunspot behaviour for his forecasts.

It really would not surprise me at all these warm temperatures seem to be here allot more often compared to last year this time. Although maybe these warmer temps will bring storms???

Storm boy – preparing the camera for the season ahead ;-)

Sydney - Warmest region in New South Wales for 4/9/2009

Unusual, Western Sydney including Penrith and Liverpool as well as Batemans Bay (New South Wales South Coast) and Kempsey (New South Wales Mid North Coast) recorded the warmest maximum temperatures in New South Wales of 26C for 4/9/2009. That is well above the long term averages of between 21C - 22C for September across Sydney (Source BOM Weather Stations for 4/9/2009).

If anything, the Sydney region was the warmest region to be in New South Wales for the day.

Harley Pearman

First 30C temperatures for the season in South West New South Wales and Victoria 12/9/2009

Maximum temperatures have been forecast to reach 30C across some inland areas of New South Wales and Northern Victoria for 12 and 13 September 2009 as well as for the Sydney region.

The first 30C temperatures for the spring / summer season as at 12.15 pm 12/9/2009 have occurred at Deniliquin, Swan Hill and Hay in Southern and South Western New South Wales and Northern Victoria. Hence this is the first significant warm day for south west New South and Northern Victoria for the season.

With 30C temperatures predicted for Sydney both Saturday and Sunday it is already warming up across the city with temperatures reaching 27C and 28C as at 12.15 pm across parts of the city away from the coast. If as expected temperatures reach 30C for Western Sydney this would be the first 30C day for the spring / summer period for the city (Source BOM Weather Stations as at 12.15 pm 12/9/2009).

Harley Pearman

A warm weekend across South East Australia 12/13 September 2009

Much of far Western and South Western New South Wales recorded 30C maximum temperatures for 12/9/2009 with the highest being 33C at Hay, Pooncarie, Ivanhoe and surrounds. Further, 30C plus temperatures also penetrated into Victoria including 34C at Mildura and 31C at Yarrawonga (All figures checked from various weather stations for 12/9/2009). Melbourne also experienced 29.9C which is unseasonal.

However 30C maximum temperatures also reached into areas that do not always see them such as Green Cape 30.3C and Merimbula 31C. It reached 32C at Bega and 30.1C at Ulludulla on the New South Wales South Coast.

Most of Sydney recorded 30C temperatures for the day including 31C at Parramatta and 31.4C at Penrith.

Currently Sunday 13 September 2009, most of Sydney is enjoying a second day in a row of 30C temperatures including 32.2C in Sydney (BOM 2.06 PM) and 32.6C at Penrith (BOM 1.07pm), all well above the September average. I took my Scientific Oregon weather station Model BAR916HG to Bella Vista and between 1.07 pm and 1.40 pm the temperature in the shade was fluctuating between 30.7C and 31.4C which is reasonably close to what was happening elsewhere across Sydney. I did note that the humidity levels on my device was showing 18% which is quite low for the same time period.

It has been a warm weekend across large areas of South East Australia with maximum temperatures being well above the average.

Harley Pearman

As Harley mentioned in the previous post, Melbourne city recorded 29.9C, which is a new record for the hottest day for first half of September, the city's record for September is 31.4C  on the 28th September 1928.

Col

Yes only 12 degrees above average for Sydney today. Though back closer to normality tomorrow with 23 forecast.

A friend interstate asked me if that meant storms (obviously not tonight). But that has led me to think that despite the warm temps that may continue into summer will this in fact be a poor storm season? My reasoning being that NSW is so dry at the moment there will be a lack of moisture from evaporation west of here to give rise to good storms? Or does the moisture come from elsewhere (higher level systems being blown across from SA etc).

Though if lack of moisture west is a problem in storm formation, one decent dump could change that then the moisture becomes self perpetuating.

3rd 30C day for September - Sydney 17/9/2009

For the third time this month being September 2009, maximum temperatures across Sydney exceeded 30C. Maximum temperatures fell within a narrow range of 32C to 33C except at Terrey Hills where it was a little cooler on 30C. The maximum temperatures were at least 11C above the long term average and occurred on a day where day break was greeted with morning fog.

Maximum temperatures across New South Wales on the same day (Figures are for 3 pm BOM Weather Stations 17/9/2009) include 36C at Brewarrina (Hottest locality), 35C at Walgett, 34C at Bourke and Nyngan and 33C at Collarenebri, in North West New South Wales. It was also warm across the Hunter Valley (Between 25C and 32C) and it reached 31C at Batemans Bay on the New South Wales South Coast.

Interestingly Armidale at 980 metres in elevation and Glenn Innes at 1,069 metres in elevation on the New South Wales Northern Tablelands both reached 25C which was 7C warmer than the maximum of 18C that occurred at Broken Hill and Pooncarie in far western and south western New South Wales thanks to cloud and or light rain occurring in that area of the state.

Harley Pearman

4th 30C day for September - Sydney

Currently maximum temperatures for September are tracking well above the average for Sydney and suburbs thanks to some rather warm days. Prior to the evening thunderstorm of 22/9/2009, maximum temperatures for Sydney topped between 30C and 32C again for the city. This is the 4th such day for September in which maximum temperatures have reached 30C or more across Western Sydney.

In addition, maximum temperatures where I live in Blacktown topped out at 29.5C on 20/9/2009 and 29.5C on 23/9/2009 as well as the 31.5C on 22/9/2009. Further overnight minimum temperature for Blacktown 25/9/2009 was 18C. (Weatherzone)

Despite the occasional cool day, the trend for September 2009 is one in which average temperatures will be well above the long term average.

Harley Pearman

September 2009 - Maximum and minimum temperature review - New South Wales only

Sydney

The month of September was very warm across the city and generally temperatures were mostly above average night and day. There were 4 days in Blacktown in which maximum temperatures reached 30C which is above average. The figures for 6 selected locations across the city are stated below with data obtained from weather stations via Weatherzone:-

Suburb            Av Max       Av Min            Normal Av Max      Normal Av Min

Bankstown       23.5C         9.5C               21.5C                  8.7C
Campbelltown   23.4C         8C                  21.8C                  6.7C
Parramatta      23.8C         10.7C              21.5C                  9.3C    
Penrith            24.9C         9.3C               23.1C                  9.5C
Prospect         24C            11.5C              21.2C                  9.3C
Sydney           23.1C         13.5C              19.9C                 11C      

Maximum temperature anomaly (NSW only)

The maximum temperature anomaly plot shows that Sydney experienced maximum daytime temperature anomalies that were generally 2C to 3C above average for the month. Additionally the Hunter Valley and the Mid North Coast experienced maximum daytime temperature anomalies of 3C to 4C above average for the month. Maximum temperature anomalies across the remainder of the state except for a small portion in South East New South Wales along the Murray River and a tiny area in Northern New South Wales were 1C to 3C above average for the month. The temperature anomaly in that South East portion along the Murray River and that Northern area of the state varied from 0C being average to 1C above average. Generally, the month of September across New South Wales with a small exception was warmer than normal.

Minimum temperature anomaly (NSW only)

The minimum temperature anomaly plot shows that South East New South Wales including Sydney and North West New South Wales experienced minimum temperature anomalies of 1C to 2C above average. Additionally, South West New South Wales, a portion of the Mid North Coast and the Northern inland of New South Wales experienced minimum temperatures that were 0C to 1C below average. The rest of the state experienced temperatures that were 0C to 1C above average. Hence excluding the south west, a portion of the Mid North Coast and parts of the northern inland, minimum night temperatures elsewhere were above average.

The plots described above with reference to New South Wales are attached below. They have been generated from the Bureau of Meteorology "Land and Water Site" specific for temperatures and dated 3/10/2009.

Harley Pearman

Warm weather returns to Western Sydney 21/10/2009

The warm weather has finally returned following a respite. Since October 1 2009, there were 11 days in a row in which the maximum temperature failed to the reach the monthly average for Blacktown. That period lasted from 2/10/09 to 12/10/09. It reached a maximum of 24.6C on 13 October before maximum temperatures dipped slightly again for 5 more days. Then on 20 and 21 October, maximum temperatures soared past 30C for 2 days in a row.
(Source Weatherzone - Prospect Weather Station daily weather records).

The inland suburbs of Sydney away from the coast also experienced 2 days in a row of 30C temperatures.

It reached 31.2C on the 20 October and the 3pm BOM record for 21/10/09 shows that the temperature was 34C at Prospect / Blacktown.

Nightime average temperatures for October are currently above average by 1.2C at Blacktown but as at 20/10/09 maximum daily temperatures were still 1.8C below average. This recent warmth should change that.

Of interest maximum temperatures reached between 33C and 36C across Sydney for 21/10/09 being the 3 PM BOM readings. Penrith was the hottest suburb with Terrey Hills being the coolest. The highest temperatures across New South Wales for the day were Tibooburra where it reached 38C followed by 37C at Bourke, Brewarrina and Ivanhoe. Large areas of New South Wales also experienced a warm day with maximum temperatures soaring into the 30s.

Harley Pearman

October 2009 weather review for Sydney

After a promising start on the 1/10/2009 in which maximum temperatures soared to 33C across Western Sydney, a cool change on the 2nd and a much stronger cold change on the 3rd heralded the beginning of a protracted spell of cool or wet weather across the city. The spell of cool temperatures did not lift until 13 October. Maximum temperatures did not reach 30C again until 20 and 21 and again on the 23 across Western Sydney. It did reach 30C at Penrith on the 30th giving that locality 5 days where the maximum temperatures reached 30C for the month.

There were only 4 days in which maximum temperatures reached 30C where I live and here in Blacktown, maximum temperatures reached or exceeded the average on only 11 days. Further, there were 8 days in which the maximum temperature failed to reach 20C at Blacktown.

Maximum daily temperatures were below average right across Sydney for the month which went against the expected forecast models as suggested by POAMA. In some areas across Sydney, night time minimum temperatures were a little above average but below average in other areas.

The month of October is a stark contrast to September. The wind direction, cloud cover and rainfall had a significant impact on daily average temperature conditions. There was 180 mm of rain at Observatory Hill (Sydney) and 101.7 mm at Blacktown. Other areas across the city had high rainfall totals as well. The average temperature conditions at seven selected weather stations across Sydney are shown below with all details from the various weather stations via Weatherzone.
 
Suburb name            Av Max     Av Main             Normal Av Max          Normal Av Min

Bankstown               22.2C       12.1C                23.4C                      11.8C 
Campbelltown           22.9C       10.2C                24.1C                      9.9C
Parramatta              22.3C        12C                  23.9C                      12C     
Penrith                   24.4C        11.9C                25.8C                      12.1C 
Prospect                 23C          12.4C                23.7C                      12.1C   
Richmond                23.2C        11.1C               25.1C                       11C
Sydney                   21.4C       14.1C                22.1C                      13.6C   

Harley Pearman

October 2009 weather review for New South Wales

The plot below has been generated from "Water and the Land" - Bureau of Meteorology 3/11/2009 for maximum temperature anomalies for the month of October.

Generally, maximum daily temperatures were below average for the South East region and North West region of New South Wales. Only the inland central regions, Hunter Valley and north east experienced maximum daily temperatures that were at least average or 1C to 2C above average.

Additionally night time minimum temperatures ranged from below average to just average for the month across the whole of the state.

Hence it is concluded that maximum and minimum temperatures for the month of October did not fully follow the predictions as suggested by the POAMA models of a warmer than normal month.

Harley Pearman

Maximum temperatures for 3 November 2009 for Sydney

Sydney today has experienced its hottest day since 8 February 2009. Maximum temperatures soared to 38C and 39C in many areas of the city including:-

Campbelltown - 38.3C at 2.56 pm.
Penrith - 39.2C at 2.40 pm.
Sydney Olympic Park - 38.9C at 3.29 pm.
Sydney Airport - 39.2C at 3.43 pm.

(Source Bureau of Meteorology Weather Stations)

At Blacktown the maximum temperature reached 30.8C on the 1 and 38C on the 3 and so far it has been a warm start to the month. There is a southerly change on the New South Wales South Coast moving north along the coast and it will be a big contrast for the 4 November with temperatures in the low 20s, cloudy and a cool onshore wind present.

Harley Pearman