Heavy rain could bring flooding

20:24, Aug 10 2012

Already wet conditions could result in parts of Canterbury flooding as heavy rain is forecast to start this weekend.

MetService is forecasting six days of rain for Christchurch starting tomorrow, with clearing skies expected the following Saturday.

Blue Skies Weather forecaster Tony Trewinnard said a cold, humid southeasterly airflow would increase over Canterbury tomorrow and become colder early on Monday. He said periods of rain were expected to develop early tomorrow, with some brief heavy falls possible during the afternoon and evening. Cold southerly winds were expected to slowly increase to become strong and gusty by tomorrow night.

However, today is expected to escape the rain, which is good news for those playing winter sports and the first Christchurch Youth Market at noon in Barbadoes St.

Trewinnard said about 30 to 40 millimetres of rain was expected over 36 hours, starting tomorrow, and combined with already wet conditions, could cause flooding.

"[It] isn't the amount you'd expect to cause flooding, but everything is wet and the rivers quite high, and even a moderate amount on Sunday and Monday could be enough to produce flooding," he said.


About 20 to 30 centimetres of snow was expected above 600 metres on the plains and foothills.

Trewinnard said some sleet was possible to low levels and snow flurries to 200m on Monday. However, showers were expected to clear later in the afternoon or evening.

Strong, gusty southwesterly winds were expected to ease slowly during the day.

"Wind chills will be significant," he said.

About 5cm to 10cm of snow was possible above 200m, but no significant accumulations were expected at lower levels.

Mostly dry weather is expected from Tuesday onwards.

The Press