MONTHLY WEATHER REVIEW - ARMIDALE NSW

SEPTEMBER 2012

September 2012 was cool, sunny and dry.

The total rain of 28.6 millimetres was well below the long term average, and all falls were light with most of the rain falling in the second half of the month. The highest daily fall was 8.6 mm on the 17th.

Numerous sunny days and clear nights kept day temperatures higher than normal and overnight temperatures lower than normal. 20.0C or higher was reached on 12 days.

There were two notable temperatures extremes - see below.
There were 21 frosts which was the highest for September since 2001.

Thunderstorm activity was higher than normal with storms on five days, two of the storms produced hail.

Winds were mostly moderate westerlies which is normal for this time of year.

Noteworthy events:
2nd & 3rd - The minimums of -5.9C on the 2nd and -6.0C on the 3rd were Armidale’s coldest September temperatures since 7th Sept 1995 (-6.4C). Cold southerly winds following a cold front which passed through on 30th August had chilled surface air temperatures allowing severe cooling to occur overnight under clear skies on the 1st/2nd and 2nd/3rd.

SEPTEMBER 2012 STATISTICS (long term averages in brackets)

Rainfall: 28.6 mm (51.5 mm)

Rain days: 8 (8)
2012 rainfall total Jan to Sep: 434.2 mm (547.7 mm)

Average maximum temp: 19.0 deg (17.5 deg)

Average minimum temp: 1.2 deg (2.6 deg)

Highest maximum temp: 25.0 deg on the 28th

Lowest maximum temp: 12.0 deg on the 1st

Highest minimum temp: 12.1 deg on the 7th

Lowest minimum temp: -6.0 deg on the 3rd

Fine sunny days: 22 (19)

Ideal weather days: 4 (2)

Days with thunderstorms: 5 (2)

Days with frosts: 21 (15) light: 8, moderate: 8, severe: 5

Days with fogs: 1 (2)

Wind direction at 3pm & number of days: W: 17, SW: 6, S: 4, NW: 2, E: 1

Average daily pan evaporation: 3.4 mm (3.2 mm)

Thunderstorm details:

13th: 4.00-5.30pm - moderate & slight storms from south-west - 2.4 mm rain
17th: 11.10am - slight hail shower - hailstones up to 5 mm diameter - no thunder
1.45-2.45pm - moderate & heavy storms from north-west
2.10pm - small hail - total rain 7.6 mm
18th: 3.15-3.45pm - slight storm from west
6.50-7.15pm - slight storm from west - 5.8 mm from both storms
21st: 12.40-1.10pm - moderate storm from west - 4.8 mm rain
24th: 10.15am - thunder heard in north - no rain
11.30am-12.00 noon - moderate storm from west - 2.4 mm rain - small hail at 11.48am