Niwa predicts warm weather ahead
NIWA is again predicting warm weather for much of the southern region over the next three months.
Niwa National Climate Centre forecasting principal scientist Chris Brandolino said high pressure was expected to be a prominent feature around New Zealand, leading to more extended dry spells for the Far North, East Cape and Canterbury.
‘‘So far this summer, the country’s climate patterns have been influenced by a nontraditional central Pacific La Nina. This is expected to continue over the next three months.
‘‘Patterns of high pressure and occasional tropical winds will continue to produce periods of above average warmth into autumn [March and April], although variable air flow patterns can allow for some cooler air masses to emerge from the Southern Ocean from time to time.
‘‘Rainfall is about equally likely to be near normal or below normal in the north and east of the North Island and west of the South Island.
‘‘Near normal rainfall is expected in all other regions.’’
He said the tropical Southwest Pacific might have intermittent cyclone activity during February.
‘‘Should one of these features or their moisture affect New Zealand, heavy rainfall that can cause flooding would be possible for some regions, but it isn’t possible to predict where it would happen weeks in advance.
‘‘On average, one extropical cyclone passes near the country each year. Significant rainfall, damaging winds, and coastal inundation can occur during these events.’’
Between February and April, temperatures in Southland, inland Otago and the West Coast were about equally likely to be above average or near average, he said.
Rainfall totals, soil moisture levels and river flows in the area were about equally likely to be near normal or below normal.
And in coastal Otago, temperatures were also about equally likely to be above average or near average, and rainfall totals, soil moisture levels and river flows were most likely to be near normal.
‘‘While the oceanic La Nina has peaked, the atmospheric expression of La Nina is expected to continue for at least the next three months.
‘‘In the subsurface equatorial Pacific, ocean temperatures increased for the second consecutive month in the east.
‘‘Conversely, in the westcentral Pacific, the cool pool intensified slightly at depth.
‘‘This suggests that the trend away from La Nina will be slow rather than abrupt.’’