Tuesday, 1 June 2010 - Seasonal Climate Summary for New South Wales - Product code IDCKGC15R0

New South Wales in autumn 2010: Wettest autumn in 10 years

• NSW and the Murray Darling Basin record above average autumn rainfall for the first time in 10 years
• Above average maximum and minimum temperatures
• 10th consecutive autumn with above average maximum temperatures

Details Extremes Maps Records Summaries Important notes the top

Rainfall

Reflecting the pattern of distribution seen in March and April, rainfall across NSW during autumn was distinctly divided east and west of the Divide. Average to below average rainfall was recorded east of the Divide, and average to above average rainfall was recorded west of the Divide. However, the overall statewide average rainfall for autumn was 141.8 mm, which is slightly below the historical average¹of 142.7 mm. Despite the below average statewide rainfall total, it was the wettest autumn since 2000 (193.0mm) for NSW.

In contrast, the Murray Darling Basin (MDB) recorded a basin-wide average of 152.4 mm which is above the historical average of 118.9 mm. This is the wettest autumn since 2000 for the MDB, when 158.9 mm of rainfall was recorded.

Slow-moving high pressure systems in the Tasman Sea were a dominant synoptic feature during autumn, and contributed to the dry conditions east of the Divide. Persistant northerly flow across the state, generated by these systems, suppressed the moist onshore flow that usually brings rain to these areas, particularly coastal regions. A series of low pressure troughs throughout the season contributed to the rainfall west of the Divide, with a complex low pressure system bringing significant rainfall to the south coast in late May.

See a map of rainfall deciles.

Temperature

Autumn temperatures were close to average across NSW, but varied significantly during individual months. Despite record warmth in April, close to average temperatures were recorded in March and May, bringing the statewide average mean temperature for autumn to 17.9°C, just 0.3°C above the historical average of 17.6°C.

With slow-moving high pressure systems in the Tasman Sea clear skies and warm northerly winds were a dominant feature across NSW during autumn, and resulted in above average maximum temperatures throughout much of the state. The statewide average maximum temperature was 24.4°C which is 0.4°C above the historical average of 24.0°C. This is the 10th consecutive autumn with above average temperatures in NSW.

Minimum temperatures varied significantly during autumn, with close to average minimums in March, very much above average minimums in April and below average minimums in May. However, the overall statewide average for autumn was 11.4°C, just 0.2°C above the historical average of 11.2°C.

Some sites had their highest autumn mean daily maximum temperature on record.
See a map of maximum temperature anomalies.
See a map of minimum temperature anomalies.

Other phenomena

Northwestern NSW rivers were awash with floodwaters, following torrential rain in Queensland, during early March.

The far southeastern coast of NSW experienced very heavy rainfall on the 30th - 31st May, under the influence of an East Coast Low that brought heavy rainfall to most southern regions.

Details Extremes Maps Records Summaries Important notes the top

Details Extremes Maps Records Summaries Important notes the top

Details Extremes Maps Records Summaries Important notes the top