Another busy cyclone season is on the way for Queensland say Australian forecasters at the Bureau of Meteorology (BOM) – but New Zealand may be spared this year says our own NIWA.

In BOM’s recent Tropical Cyclone Season Outlook meteorologists predict above average cyclone activity this summer around Australia – in particular Queensland, which was devastated by La Nina floods and monster cyclone Yasi earlier this year.

While this prediction doesn’t include New Zealand it does cover to 160 East – which is basically the half way mark across the Tasman Sea.  BOM don’t make predictions further east of that line.

But NIWA says conditions around New Zealand may not be so favourable for cyclones this summer, predicting below average numbers but increased activity in the late season near North Queensland and French Polynesia.

NIWA, along with government forecaster MetService, have issued a tropical cyclone outlook on behalf of collaborating organisations from the southwest Pacific and the US.

These organisations across the Pacific are predicting below average tropical cyclone occurrence for the 2011 – 12 season.  “On average, nine named tropical cyclones occur in the southwest Pacific (between 135°E and 120°W) each season (November – April). The forecast indicates that 5 – 8 named cyclones are expected for the November 2011 – April 2012 season. Activity is expected to be below normal to the west of the Dateline, except near North Queensland where near normal or slightly above activity may occur. During the second half of the season, higher than normal activity is also likely to the east of the Dateline near the Society Islands and Austral Islands” said a NIWA press release issued yesterday.

The release went on to say that most countries west of the International Date Line, including New Zealand (from ex–tropical cyclones), are likely to experience close to normal or lower than normal activity because of the style of La Niña that is currently developing

WeatherWatch.co.nz says that BOM’s prediction of more cyclones than average affecting eastern Australia this coming season doesn’t indicate a higher risk for New Zealand either.  “Our tropical storms usually start north east or north of New Zealand and while many cross over the Coral Sea, like Yasi, or form there, they don’t automatically come our way later on.  If they do, it appears cooler sea temperatures this summer should see them weakening” says head weather analyst Philip Duncan.

But Mr Duncan points out a reduced risk doesn’t mean we won’t get one.  “We can have a below average season and still be hit by a devastating tropical cyclone in the north.  Residents, especially in the top half of the North Island, should always be prepared for a summer cyclone – and now is a good time to ensure you have a well stocked survival pack”.

Cyclone Wilma earlier this year cost northern New Zealand at least $25 million in damage with slips and flooding isolating numerous communities.  The storm was fast moving which limited increased damage.

La Nina, which brings cooler sea waters to the equatorial Pacific, brings much warmer sea surface conditions to eastern Australia.  Those warmer seas produce more storms.

Our cyclone season starts in November and ends in April.

– WeatherWatch.co.nz with NIWA, BOM