MONTHLY WEATHER REVIEW - ARMIDALE NSW

NOVEMBER 2011

November 2011 was a warm and humid with record breaking rains.
After heavy falls on the 12th-13th, 17th-18th and 23rd-26th, the rainfall total for the month of 244.4 mm was the highest on record for November (previous highest 232.4 mm in 1866, 149 years of records). Further details of the two major rain events below.
Temperatures were higher than normal with 25 degrees exceeded on 14 days. Numerous cloudy nights ensured that overnight temperatures remained well above normal resulting on no frost level minimums.
Thunderstorm activity was close to normal and there were no hailfalls.
Winds were mostly light to moderate westerlies.

Noteworthy events:
12th-13th - An active trough over northeastern New South Wales produced widespread thunderstorms in the afternoon and evening of the 12th, and right through the day on the 13th. Several storms were very lightning intensive with almost continuous thunder lasting for extended periods. On the 13th heavy rain fell in the afternoon and evening. Total for the weekend was 48.0 mm. There was no hail.
23rd-26th - An intense low pressure trough over northern New South Wales generated widespread moderate to heavy falls of rain over the Northern Tablelands during the four day period.
Armidale recorded 87.6 mm for the 24 hours to 9am on Thursday the 24th which caused moderate flooding in Dumaresq Creek. This was the highest daily fall of rain for 17 years.
The rain and flooding continued through to Saturday the 26th. The flooding reached its peak early on Saturday afternoon after 15 mm fell between 9am and noon. All low lying areas along the creek including playing fields were inundated. Marsh St, Markham St and Niagara St were the only north-south roads open within the city linking the two sides of Armidale during the flooding.
Total rain from this event was 170.4 mm.

NOVEMBER STATISTICS (long term averages in brackets):

Rainfall: 244.4 mm (82.7 mm)

Rain days: 10 (9)
2011 rainfall total Jan to Nov: 936.4 mm (698.4 mm)

Average maximum temp: 24.2 deg (22.6 deg)

Average minimum temp: 11.3 deg (8.8 deg)

Highest maximum temp: 30.3 deg on the 15th

Lowest maximum temp: 16.7 deg on the 24th

Highest minimum temp: 15.6 deg on the 26th

Lowest minimum temp: 4.1 deg on the 3rd

Fine sunny days: 13 (14)

Ideal weather days: 0 (1)

Days with thunderstorms: 4 (6)

Days with frosts: 0 (1.5)

Days with fogs: 0 (1)

Wind direction at 3pm & number of days: W: 9, SW: 9, NW: 5, E: 4, NE: 2, SE: 1

Average daily evaporation: 4.1 mm (4.5 mm)

Thunderstorm details:

12th: 4.00-4.35pm - moderate storm from west
11.15-11.50pm - slight storm from west - 14.4 mm rain from both storms
13th: 8.45-10.30am - thunder heard - no rain
10.30am-2.15pm - moderate & slight storms from west - 5.6 mm rain
5.00-11.00pm - moderate & slight storms from west - 28.0 mm rain
17th: 7.15-8.30pm - slight storm from west; 10.00-11.00pm - thunder heard - no rain
29th: 2.30-4.15pm - thunder heard in north-west - no rain