Wednesday, 1 September 2010 - Monthly Climate Summary for Queensland - Product code IDCKGC24R0

Queensland in August 2010: 

A very wet month for most

• Rainfall was above average over most of Queensland
• Temperatures were above average in the northeast
• Daytime temperatures were cooler in the south and west

Several upper troughs passed across Queensland during August leading to very much above average rainfall in a broad band extending from the northwest to the southeast and above average rainfall over most of the remainder. The increased cloudiness led to cooler daytime temperatures across the western and southern districts. Northern Queensland has been warmer than average during recent months and this trend continued during August.

Details Extremes Maps Records Summaries Important notes the top

Weather Summary

At the beginning of the month a large high pressure system moved into the Great Australian Bight, driving fresh dry and cold southwest to southeast winds across southern Queensland in the wake of a surface trough and southeast trade winds with isolated showers across northern districts. Showers and drizzle brought light falls to the southwest slopes of the southern interior. Early frosts affected southern and central districts from the 2nd and days were cool. On the 5th a trough moved through western Queensland and reached the southeast interior during the evening. High cloud and patchy light rain accompanied the system over the southern interior and extended east with the trough. The trough cleared the southeast coast during the following day contracting the showers offshore.

Generally fine conditions prevailed over most of the state during the next few days with above average temperatures over the far northern tropics and the below average temperatures in the south with early frosts.

By the 9th the high pressure system was located over the Tasman Sea with moist east to northeast winds across eastern Queensland with isolated shower and drizzle areas. A trough entered western Queensland with winds tending warm northwest to northeast as it approached and isolated afternoon showers and thunderstorms developed over the central and southern interior. High cloud and patchy light rain extended over northwestern Queensland ahead of an approaching upper level trough.

Widespread rain areas and isolated thunderstorms spread across tropical, central and southern parts with moderate to locally heavy falls as the upper trough moved steadily east across the state. In the wake of the cloud and rain band cooler and drier south to southwest winds spread across the state as a new high pressure system moved steadily east across the Great Australian Bight. The upper trough moved offshore during the 12th and fine and cool to cold conditions spread over most of the state with moderate southwest to southeast winds, initially fresh and gusty over southern Queensland and also over the northern tropics. A low pressure system deepened over the Tasman Sea during the 12th, producing a tight gradient over the southeast corner of Queensland and necessitated severe weather warnings for damaging west to southwest wind gusts. The Darling Downs and Granite Belt experienced cloudy periods and areas of drizzle and frosts were widespread over southern districts as winds eased.

As the deep low pressure system moved east, a high pressure system became the dominant influence and fine conditions returned to Queensland, although very isolated showers persisted in the far north. A new front brought a southwest change to southern Queensland during the 15th and moved off the southern coast during the afternoon

Warmer north and northwest winds extended over the interior of Queensland as a trough approached from the west during the 18th and 19th. The trough reached the southeast and central coasts during the 20th followed by a cooler southwest change. This system was accompanied by an upper trough that extended high cloud and patchy rain into far western Queensland initially and then spread through central and southeast parts. Unusually hot conditions affected northwest Queensland from the 18th until the 24th. A new upper trough extended a band of rain and local thunder across the southern interior from the 22nd, which contracted into the southeast of the state and weakened on the 24th. Yet another upper system extended widespread cloud and patchy rain east over southern and central parts of the state during the 24th and 25th, which contracted north and dissipated during the next few day as the upper trough moved off the south coast. Some moderate falls were recorded during these events.

The next high pressure system moved into the Great Australian Bight during the 28th and extended dry southwest to southeast winds and fine conditions to most of the state until the end of the month, apart from isolated showers about the northeast tropics in an onshore flow. The dry air brought a return to cool morning temperatures about the central and southern districts with widespread frosts about the southern interior. As the high shifted further east, the firm coastal ridge increased onshore winds and brought isolated showers to exposed parts of the east coast, more frequent and widespread about the northeast tropical coast. A deepening instability in the northern tropics produced isolated moderate to heavy falls along the northeast tropical coast and also triggered isolated storms over the Peninsula. Warm northerly winds extended over the interior at the end of the month.

Rainfall

August rainfall was amongst the highest 10 % on record for most of eastern and northern Queensland with the Northern Peninsula and some location in the southeast receiving record high August totals. Most other parts of the state also received above average amounts.

Averaged across the state 31.8 mm was recorded, this ranking 104 of 111 August totals since 1900 and the highest since 1998 and prior to that the 1988 and 1966 totals.

A significant upper trough passage during the 10th to 12th produced widespread falls across a large part of the state with some of the highest daily falls being 130 mm at Gargett, 123 mm at Rosedale and 120 mm at Mirani to 9am on the 11th and many locations recorded their highest August daily total and also highest August total rainfall on record. A few locations recorded moderate falls late in August during the passage of several upper troughs.

Some moderate to heavy falls were also reported near the end of the month in the far north as the onshore stream increased on the east coast and a more unstable airmass developed over the Peninsula. Lucinda Township recorded 156.4 mm on the 29th in very localised showers.

The wettest overall was 552.8 mm at Bellenden Ker Top Station, followed by 311.0 mm at Babinda Post Office, 295 mm at Bulgun Creek Alert, 270.2 mm at Daradgee and 263.2 mm at Lucinda Township.

The driest overall was around the southern Gulf of Carpentaria coast and the far northwest where some locations recorded no rainfall.

The wettest single day was 277 mm at Bellenden Ker Top Station on the 31st, followed by 156.4 mm at Lucinda Township on the 29th, 130.0 mm at Gargett Alert on the 11th and 123.0 mm at Rosedale Post Office on the 11th.

Temperature

Northern Queensland has been warmer than average during recent months and this trend continued during August.

Maximum temperature

Mean maximum temperatures graded from 1 to 2 °C above the long term August average over the Penisula and central coast to near 3 °C below average across the southwest.

Hot north and northwest winds extended over the interior of Queensland as a trough approached from the west during the 18th and 19th and maximum temperatures were more than 6 °C and in some parts more than 10 °C higher than the long term average. Unusually hot conditions persisted over northwest Queensland from the 18th until the 25th and then contracted to the northern Peninsula. 

The hottest day was 37.2 °C at Julia Creek Airport on the 19th, followed by 37.1 °C at Cloncurry Airport on the 19th, followed by 36.9 °C at Croydon Township on the 18th, followed by 36.9 °C at Normanton Airport on the 18th.

The warmest days on average were 34.2 °C at Kowanyama Airport, followed by 33.5 °C at Scherger RAAF, followed by 33.4 °C at Weipa Aero.

The coolest days on average were 14.2 °C at Applethorpe, followed by 15.0 °C at Stanthorpe Leslie Parade, followed by 16.7 °C at Toowoomba Airport.

The coldest day was 9.1 °C at Applethorpe on the 12th, followed by 9.7 °C at Stanthorpe Leslie Parade on the 12th, followed by 10.5 °C at Applethorpe on the 25th.

Minimum temperature

Mean minimum temperatures were 1 to 3 °C warmer than the long term average along the tropical east coast and within a degree of average elsewhere and generally cooler across the southwest.