Monday, 3 December 2007 - Monthly Climate Summary for Canberra area - Product code IDCKGC1xx0

Stormy and wet with record warm nights in Canberra during November

Summary

• warm days, average maximum temperature 25.1°C or 2.5°C above the historic average
• 6 consecutive years with above average November maximum temperatures
• 8 hot days exceeded 30°C (normally 2 hot days)
• warm nights, average minimum temperature 11.8°C was highest ever recorded in November
• 5 out of last 6 years with above average minimum temperatures
• persistent mild nights with temperature not falling below 5°C the whole month
• well above average rainfall
• 7thunderstorms, highest in November for 13 years.
• below average sunshine hours

 

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Rainfall

Canberra Airport recorded a total rainfall of 94.0 mm during November, which is significantly above the historic average of 63.8 mm, and the wettest November since 2000 (when 121 mm was recorded). Welcome rain and thunderstorms associated with a low-pressure system early in the month, and again on the 23rd, brought some relief from the dry conditions that had persisted in eastern parts of the ACT since June. There were 12 rain days during November, compared to the average of 10 days. Rainfall totals varied considerably over the ACT during November with the highest totals in the south-west and the lowest totals in central Canberra. The highest in the ACT was 150.4 mm at Mount Ginini AWS with the highest suburban total of 127.6 mm at Tuggeranong AWS. The lowest total was 63.0 mm at Deakin.

Persistent high-pressure systems near Tasmania for most of the month caused prevailing moist E to SE airstreams over NSW including Canberra. This combined with inland low-pressure troughs and cold, unstable air in the upper atmosphere to produce the above average rainfall for the month. Much of the month's rain occurred during thunderstorm activity.

Temperatures

Canberra experienced a warm November with the mean daily temperature (the average of the mean maximum and mean minimum temperatures) at Canberra Airport of 18.4°C, significantly above the historic average¹ of 15.7°C.  The average maximum (day-time) temperature during November was a very warm 25.1°C which is well above the historic average¹ of 22.7°C and ranks 9th highest since records commenced in 1939. There were 8 hot days when the maximum temperature exceeded 30°C - normally Canberra would expect only 2 hot days in November. The 8 days above 30°C were consecutive days (14th to 21st), which is the 2nd longest hot spell on record in November, the longest being in 2006 when there was 11 consecutive days above 30°C (records since 1939).

Canberra has now recorded 6 consecutive years with above average maximum temperatures in November.

Canberra also experienced very warm nights during November with an average minimum at the airport of 11.8°C being 3.0°C above the historic average¹ of 8.8°C. This is the highest average minimum temperature on record for Canberra in November (previous highest 11.6°C in 2000). There was a distinct lack of cold nights with the temperature not falling below 5°C the whole month. Normally Canberra would expect 5 nights in November with a minimum temperature below 5°C.

The high minimum temperatures were in part due to moist, humid air from the north-east and a greater than normal cloud cover limiting radiative cooling at night. Over 34% of winds were from the E-NE which is double the normal frequency from this direction. For 5 out of the last 6 years, Canberra has recorded above average minimum temperatures in November.

Extremes of temperature at Canberra Airport ranged from a high of 33.4°C on the 20th and 21st to a low of 6.1°C on the 7th. Corresponding extremes for Tuggeranong ranged from a high of 33.4°C on the 20th to a low of 5.8°C on the 10th. The lowest temperature in the ACT was −1.0°C at the high elevation site of Mount Ginini AWS (1760 m) on the 5th, 6th and 7th.

 

Other phenomena

No frosts were recorded at Canberra Airport during November (historic average 2 frosts) and also no fogs (average 1 fog).  Cloud generally increased during the afternoons associated with diurnal heating and thunderstorms resulting in below average sunshine of just 7.9 hours per day, well below the historic average 9.0 hours per day and the cloudiest November for 7 years.  Canberra's average wind run of 167.6 km per day was below the historic average of 207 km per day. There were 3 strong wind days (average 3).

Canberra Airport recorded 7 thunderstorms during November which is the highest number of storms in November for 13 years (historic average 4 storms). No hail was reported. The average air pressure of 1017.1 hPA was well above the historic average of 1013.2 hPa. Canberra Airport recorded 176 mm of evaporation during November, below the historic average of 196.2 mm. This was due mainly to the lower than normal wind speeds and high levels of humidity experienced over the ACT during the month.

Further information

Mike De Salis
Climate Information Officer
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1555
Email mikede@bom.gov.au

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Extremes for the ACT

Hottest day Highest temperature	33.4°C at Canberra Airport on the 20th and 21st 33.4°C at Tuggeranong AWS on the 20th
Warmest days on average Highest mean daily maximum temperature	25.1°C at Canberra Airport
Coolest days on average Lowest mean daily maximum temperature	24.8°C at Tuggeranong AWS
Coldest day Lowest daily maximum temperature	15.5°C at Canberra Airport on the 4th 4.0°C at Mount Ginini AWS on the 4th (elev 1760 m)
Coldest night Lowest temperature	5.8°C at Tuggeranong AWS on the 10th −1.0°C at Mount Ginini AWS on the 5th,6th and 7th.
Coolest nights on average Lowest mean daily minimum temperature	11.1°C at Tuggeranong AWS 6.7°C at Mount Ginini AWS
Warmest nights on average Highest mean daily minimum temperature	11.8°C at Canberra Airport
Warmest night Highest daily minimum temperature	16.4°C at Canberra Airport on the 22nd
Wettest overall Highest total rainfall	150.4 mm at Mount Ginini AWS and 143.8 mm at Tharwa
Driest overall Lowest total rainfall	63.0 mm at Deakin
Wettest day Highest daily rainfall	43.6 mm at Sullivan Creek (Southwell) on the 4th
Highest wind gust	85 km/h from NW at Canberra Airport on the 3rd (to 25th)

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Records

Record highest November mean daily minimum temperature
	Mean daily minimum temperature for November 2007 (°C)	Previous highest for November (°C)		Years of record	Normal for November
Canberra Airport	11.8	11.6	in 2000	69	8.8

 

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Summaries

Summary statistics for November 2007
	Maximum temperatures for November (°C)				Minimum temperatures for November (°C)				Rainfall for November (millimetres)
	Mean for November 2007	Diff from normal	Highest for November 2007		Mean for November 2007	Diff from normal	Lowest for November 2007		Total for November 2007	Normal for November	Rank of November 2007	Fraction of November normal
Canberra Airport	25.1	+2.4	33.4	20th,21st	11.8	+3.0	6.1	7th	94.0	63.8	high	147%
Tuggeranong	24.8	+1.1	33.4	20th	11.1	+1.8	5.8	10th	127.6	61.7	very high	207%
Mount Ginini (elev 1760 m)*	15.5		24.9	20th	6.7		−1.0	5th,6th,7th	150.4

* new station, no historic averages available

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Notes

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