New Zealand Climate Update 152 – February 2012

What happened in January, how our climate outlook for the previous three months turned out, global and local sea temperatures, and our outlook for February to April. 

Current Climate - January 2012

The first half of January was characterised by easterly and northerly winds, which produced wet and windy weather for areas exposed to the northeast.  In contrast, the second half of the month was very cool, with frequent southerly winds which brought unusually cool air over the country.  For the month as a whole, lower pressures than normal prevailed over New Zealand, as well as to the north and east of the country, producing a rather cool, windy, and unsettled month overall.

Outlook - February to April 2012

A moderate La Niña is in place in the tropical Pacific and is likely to persist into mid-autumn 2012. Temperatures are likely to be average in most areas but average or above average in the western South Island. Early autumn rainfall is likely to be near normal for most regions, but normal or below normal in the west of the South Island. Soil moisture levels and river flows are likely to be near normal in most regions, but normal or below normal in the western South Island. 

Retrospective - November to January Outlook

Weak to moderate La Nina conditions were projected to continue through the early summer period (November 2011 to January 2012), with mean sea level pressures forecast to be near normal or above normal across New Zealand. Moderate La Nina conditions did indeed prevail through the season, with higher pressures than normal over the Tasman Sea and the southwest South Island, and near normal mean sea level pressures over the North Island. This circulation pattern brought more southerly winds than usual across the country, during the early summer period.