Brisbane Metro in summer 2009-10: A wet end to summer

  • Thunderstorms produce heavy rainfall
  • Some hot days throughout summer

Overview

December: 

The first twenty days of December were quite dry in the Brisbane Metro area, with 12.2 mm at the Brisbane city gauge on the 16th being the highest daily rainfall during that period.

On the 20th a thundery rain band that extended from the Gulf Country to southeast districts moved over the Brisbane Metro area, producing daily rainfall totals of up to 40.6 mm (recorded in the 24 hours to 9am on the 21st) at the weather stations included in this summary.  By the 23rd, a high pressure system was located to the northwest of New Zealand and a weak low pressure system was located near the Solomon Islands. Together these systems directed very moist east to northeasterly winds across nearly all of Queensland and widespread showers and thunderstorms occurred over northern and eastern areas, especially over the southeast. Shower activity produced daily rainfall totals of up to 24.2 mm in the Brisbane Metro area in the 24 hours to 9am on the 26th. Widespread shower and thunderstorm activity produced daily rainfall totals of up to 44.8 mm in the Brisbane Metro area in the 24 hours to 9am on the 27th. Showers, tending to rain at times, produced daily rainfall totals of up to 29.4 mm in the Brisbane Metro area in the 24 hours to 9am on the 28th.  

On the 28th an upper low pressure system off the central coast generated a great depth of very moist northeasterly winds to its south, into the southeastern corner of Queensland.  The surface trough over the interior generated unstable conditions with widespread showers and thunderstorms near and east of it, while rain areas occurred over parts of the southeast and central east districts due to the northeasterly flow generated by the upper low. Daily rainfalls of up to 52.0 mm occurred in the Brisbane Metro area in the 24 hours to 9am on the 29th.  The upper low moved just inland of the central coast on the 29th and weakened, with rainfall gradually easing over southeastern parts of the state. Daily rainfalls of up to 42.6 mm occurred in the Brisbane Metro area in the 24 hours to 9am on the 30th. By the 30th, a high in the Tasman Sea extended a ridge along the Queensland east coast. The highest daily rainfall in the Brisbane Metro area in the 24 hours to 9am on the 31st was 5.1 mm.

January: 

Rain was recorded at most sites each day until the 9th in common with a large part of the rest of the state. Very little rain was recorded later, except on the 18th, until the last few days of the month.

During the last few days of January ex Tropical Cyclone Olga traversed southeast through the interior, the monsoon trough was drawn further south along the east coast and a high pressure system over the Tasman Sea helped tighten the surface pressure gradient from the south. This situation brought a strong moist east to northeast flow with showers through the Brisbane area. Rain from the interior was also advected through the area at higher levels.  Most sites recorded their highest daily total on the 30th or 31st. 

February:

Two rainfall events produced some significant daily totals; overnight on the 6th February and then during the 15th and 16th February.  Totals varied, but produced large falls in all metro sites.  Brisbane Aero was the driest metro site for February, where the site recorded 90mm for February, missing out on the substantial totals recorded in the other metro sites.

Redcliffe had a blocked rain gauge on the 16th, producing an incorrect daily total on the 17th (60 – 80mm was recorded in the area). Amberley recorded no reading to 9am on the 16th, despite 90 – 100mm falling in the area. 

Rainfall

The wettest overall was 543.9 mm at Logan City Water Treatment, and the wettest single day was 128 mm, also at Logan City Water Treatment.

See a map of total rainfall. See a map of rainfall deciles.

Maximum temperature

The hottest day was 39.7 C at Amberley AMO on the 9th of December 2009, and the warmest days on average were 31.8 C, also at Amberley AMO.

The coolest days on average were 29.2 C at Brisbane Aero, and the coldest day was 24.1 C at Amberley AMO on the 2nd of December 2009.

See a map of mean maximum temperatures. See a map of maximum temperature anomalies.

Minimum temperature

The coldest night was 12.3 C at Amberley AMO on the 19th of January 2010, and the coolest nights on average were 19.5 C, also at Amberley AMO.

The warmest nights on average were 22.1 C at Redcliffe, and the warmest night was 25.0 C at Logan City Water Treatment on the 19th of December 2009.

See a map of mean minimum temperatures. See a map of minimum temperature anomalies.

Further information

Media
(03) 9669 4057
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Extremes in summer 2009-10
Hottest day 39.7 C at Amberley AMO on 9 Dec 2009
Warmest days on average 31.8 C at Amberley AMO
Coolest days on average 29.2 C at Brisbane Aero
Coldest day 24.1 C at Amberley AMO on 2 Dec 2009
Coldest night 12.3 C at Amberley AMO on 19 Jan 2010
Coolest nights on average 19.5 C at Amberley AMO
Warmest nights on average 22.1 C at Redcliffe
Warmest night 25.0 C at Logan City Water Treatment on 19 Dec 2009
Wettest overall 543.9 mm at Logan City Water Treatment
Wettest day 128 mm at Logan City Water Treatment on 7 Feb 2010
Highest wind gust 74 km/h at Archerfield Airport on 31 Jan 2010


^ These stations have missing observations during the summer.
Summary statistics for summer 2009-10
Maximum temperatures
for summer
(C)
Minimum temperatures
for summer
(C)
Rainfall
for summer
(millimetres)
Mean for
summer
2009-10
Diff
from
average
Highest for
summer
2009-10
Mean for
summer
2009-10
Diff
from
average
Lowest for
summer
2009-10
Total for
summer
2009-10
Average
for
summer
Rank of
summer
2009-10
Fraction of
summer
average
Moreton South Coast (district 40)
Amberley AMO 31.8 +1.0 39.7 9 Dec 2009 19.5 +0.3 12.3 19 Jan 2010 209.4^ 353.6 v low 59%
Archerfield Airport 30.6 +0.8 36.1 18 Jan 2010 20.8 +1.1 16.1 4 Dec 2009 495.0 410.7 high 121%
Brisbane 30.5 +0.6 35.1 18 Jan 2010 21.9 +0.9 17.1 4 Dec 2009 484.8 361.4 high 134%
Brisbane Aero 29.2 +0.4 32.1 18 Jan 2010 21.6 +0.8 16.9 4 Dec 2009 388.8 362.8 average 107%
Logan City Water Treatment 30.5 +1.2 37.7 18 Jan 2010 21.3 +1.4 15.7 3 Dec 2009 543.9 398.6 high 136%
Redcliffe 29.2   32.7 15 Feb 2010 22.1   18.5 5 Dec 2009 ^

Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in Brisbane Metro using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 9 am on Monday 1 March 2010. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 9 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

Further information

Media
(03) 9669 4057
Enquiries