Not all Highs bring sunny weather

On Thursday 19 April 2012, New Zealand was completely surrounded by a very large High (or anticyclone). The air pressure at sea level was above 1030 hPa everywhere over New Zealand at midday on that day. Highest pressures were over inland Otago and Canterbury, peaking at 1039 hPa. Christchurch Airport was reporting 1038.2 hPa ... that's very high indeed.