The following is provided for the information
of subscribers (and as an addition to the annual summary provided in
the Annual Bird Report): http://www.bom.gov.au/climate/current/month/act/summary.shtml
ACT in March
2010: March begins and ends with rain
- Wettest March
since 1993
- Above average
minimum temperatures
- Average
maximum temperatures and mild conditions
Rainfall
Following the
very high rainfall in February, above average rainfall was again
recorded in Canberra
during March 2010, with monthly totals as high as 128mm at Mt Ginini. Canberra Airport recorded 93.2mm, almost
double the March average of 50.7mm and the highest total since March
1993 (100.8mm). This is the first March with above average rainfall in Canberra since
2003.
The rain fell
over only seven days, approximately average for March. Several small
falls occurred during the first week of the month, associated with the
passage of surface troughs, with rainfall reaching 22.4mm at Canberra Airport on the 8th. This was
followed by a period of settled conditions between the 10th and 28th,
associated with stationary high pressure systems over eastern NSW. The
month concluded with the passage of a further trough system, with
scattered rain on the 29th and 30th followed by totals of 36.6mm on the
31st, the highest daily rainfall in March since 2003. The majority of
this occurred in 20 minutes, with 20.6mm recorded between 9:40 and
10:00am on the 30th, with reports of localised flash flooding.
Temperature
March 2010 had
close to average temperatures in Canberra, with a mean maximum
temperature of 24.6°C, just 0.1°C above the March average of 24.5°C. No
days during March exceeded 30°C, well below the average of 3 hot days,
with the maximum daily temperature at Canberra Airport just 29.1°C.
However, no days occurred with maximum temperatures below 20°C at Canberra Airport, compared to an average
of 4.3 such days per year. The coldest day recorded anywhere in Canberra was 10.9
°C at Mount
Ginini AWS on the 12th.
Minimum
temperatures at Canberra
Airport averaged
11.6°C during March, 0.9°C above the historical average of 10.7°C. Four
consecutive days had minimum temperatures exceeding 15°C in the early
part of the month, with a maximum overnight temperature of 19.2°C on
the 7th, associated with the passage of a trough and cloudy conditions.
The coldest temperature recorded anywhere in Canberra was 1.6°C at Mt
Ginini on the 2nd, with overnight minimums reaching 7.5°C at Canberra
Airport on the 11th.
Wind
N-W winds
prevailed during March, forming 50% of afternoon wind flow, which is
normal for March. Winds were generally light, as expected for Autumn,
which tends to have the lowest wind speeds in Canberra. No strong wind days were
recorded, with the maximum wind gust at Canberra Airport
of 52km/hr on the 21st associated with the passage of a low pressure
trough. The highest wind gusts anywhere in Canberra were 74km/hr at Mt Ginini on
the 9th, associated with the passage of a cold front.
Other phenomena
Sunshine
averaged 8.0 hours per day at Canberra Airport
during March 2010, similar to the historical March average of 8.1. 9am
relative humidity averaged 78%, well above the historical average of
70%, with 15 days exceeding 80% at 9am. This is the highest frequency
since March 1994, with 18 such days. Average 3pm humidity was 46%,
similar to the historical average of 42%. Only one thunderstorm was
observed at Canberra
Airport on the
7th, compared to the March average of 2 thunderstorms.
