April rainfall was well above normal, almost double the month’s average total, but sandwiched between a very dry March and now May. April’s rain left river flows measuring above normal and soil moisture lying above median levels for the time of year. Groundwater levels for the month were mostly near or below normal but that might improve once April’s rain filters through. Daytime temperatures were near average but nights were warm for the time of year. Sea surface temperatures have been above average around most of New Zealand but cooler than average in Hawke Bay.
An El Niño event is expected to develop during the next couple of months and those events typically bring the region a west to southwest flow. Westerlies reduce the likelihood we’ll have above average rainfall because the western ranges help shelter us from storms coming from that direction. Forecasts suggest winter will bring us that west to southwest flow due to higher than normal sea level pressure lying to the west and lower than normal pressure to the east. That pattern leads to predictions of below or near normal winter rainfall and near normal temperatures, tempered by winds having a southerly aspect at times.
