Brisbane Metro in December 2009: Dry start, wet finish

Rainfall

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 it's 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.

The wettest overall was 196.0 mm at Brisbane Aero, followed by 182.6 mm at Archerfield Airport, followed by 182.4 mm at Logan City Water Treatment.

The driest overall was 70.2 mm at Redcliffe, followed by 84.2 mm at Amberley AMO, followed by 172.2 mm at Brisbane.

The wettest single day was 52.0 mm at Logan City Water Treatment on the 29th, followed by 44.8 mm at Archerfield Airport on the 27th, followed by 42.6 mm at Logan City Water Treatment on the 30th.

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

Maximum temperature

Mean maximum temperatures for December were above average at all Brisbane Metro sites considered in this summary.

The hottest days occurred at Amberley AMO, with 39.7 °C on the 9th, followed by 38.8 °C on the 10th, followed by 37.9 °C on the 8th.  The hot temperatures were associated with northwesterly winds.

The warmest days on average were 32.2 °C at Amberley AMO, followed by 30.8 °C at Logan City Water Treatment, followed by 30.5 °C at Archerfield Airport.

The coolest days on average were 28.8 °C at Redcliffe, followed by 28.9 °C at Brisbane Aero, followed by 30.2 °C at Brisbane.

The coldest day was 24.1 °C at Amberley AMO on the 2nd, followed by 24.9 °C at Redcliffe on the 2nd, followed by 25.1 °C at Archerfield Airport on the 2nd.

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

Minimum temperature

Mean minimum temperatures for December were also above average at all Brisbane Metro sites considered in this summary.

The coldest nights occurred at Amberley AMO with 13.9 °C on the 5th, followed by 14.4 °C on the 4th, followed by 15.3 °C on the 3rd.

The coolest nights on average were 19.2 °C at Amberley AMO, followed by 20.8 °C at Archerfield Airport, followed by 21.0 °C at Logan City Water Treatment.

The warmest nights on average were 22.1 °C at Redcliffe, followed by 21.6 °C at Brisbane, followed by 21.5 °C at Brisbane Aero.

The warmest night was 25.0 °C at Logan City Water Treatment on the 19th, followed by 24.5 °C at Redcliffe on the 25th, followed by 24.4 °C at Brisbane on the 14th.

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

Wind

The strongest wind gust was 67 km/h at Brisbane Aero on the 5th, followed by 63 km/h at Archerfield Airport on the 5th, followed by 59 km/h at Redcliffe on the 5th.

Further information

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Extremes in December 2009
Hottest day 39.7 °C at Amberley AMO on the 9th
38.8 °C at Amberley AMO on the 10th
37.9 °C at Amberley AMO on the 8th
Warmest days on average 32.2 °C at Amberley AMO
30.8 °C at Logan City Water Treatment
30.5 °C at Archerfield Airport
Coolest days on average 28.8 °C at Redcliffe
28.9 °C at Brisbane Aero
30.2 °C at Brisbane
Coldest day 24.1 °C at Amberley AMO on the 2nd
24.9 °C at Redcliffe on the 2nd
25.1 °C at Archerfield Airport on the 2nd
Coldest night 13.9 °C at Amberley AMO on the 5th
14.4 °C at Amberley AMO on the 4th
15.3 °C at Amberley AMO on the 3rd
Coolest nights on average 19.2 °C at Amberley AMO
20.8 °C at Archerfield Airport
21.0 °C at Logan City Water Treatment
Warmest nights on average 22.1 °C at Redcliffe
21.6 °C at Brisbane
21.5 °C at Brisbane Aero
Warmest night 25.0 °C at Logan City Water Treatment on the 19th
24.5 °C at Redcliffe on the 25th
24.4 °C at Brisbane on the 14th
Wettest overall 196.0 mm at Brisbane Aero
182.6 mm at Archerfield Airport
182.4 mm at Logan City Water Treatment
Driest overall 70.2 mm at Redcliffe
84.2 mm at Amberley AMO
172.2 mm at Brisbane
Wettest day 52.0 mm at Logan City Water Treatment on the 29th
44.8 mm at Archerfield Airport on the 27th
42.6 mm at Logan City Water Treatment on the 30th
Highest wind gust 67 km/h at Brisbane Aero on the 5th
63 km/h at Archerfield Airport on the 5th
59 km/h at Redcliffe on the 5th




Summary statistics for December 2009
Maximum temperatures
for December
(°C)
Minimum temperatures
for December
(°C)
Rainfall
for December
(millimetres)
Mean for
December
2009
Diff
from
average
Highest for
December
2009
Mean for
December
2009
Diff
from
average
Lowest for
December
2009
Total for
December
2009
Average
for
December
Rank of
December
2009
Fraction of
December
average
Moreton South Coast (district 40)
Amberley AMO 32.2 +1.3 39.7 9th 19.2 +0.8 13.9 5th 84.2 119.8 average 70%
Archerfield Airport 30.5 +1.0 34.5 11th 20.8 +1.8 16.1 4th 182.6 125.8 high 145%
Brisbane 30.2 +0.9 33.2 11th 21.6 +1.3 17.1 4th 172.2 128.4 high 134%
Brisbane Aero 28.9 +0.7 31.1 13th 21.5 +1.5 16.9 4th 196.0 119.3 high 164%
Logan City Water Treatment 30.8 +1.9 34.4 10th 21.0 +2.0 15.7 3rd 182.4 132.0 high 138%
Redcliffe* 28.8 +0.7 31.3 11th 22.1 +1.6 18.5 5th 70.2 117.8 low 60%

Notes

A Monthly 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 4 pm on Monday 4 January 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 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

* These sites are compared to other long-term sites in the area.

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