The Reserve Bank of New Zealand surprised no-one by keeping the cash rate unchanged at 3.0 per cent at the monetary policy meeting this morning.The RBNZ's own admission that outlook for growth had softened and an easing in forecast for the peak for inflation had made the prediction easier. This was coupled with the fact that recent economic data had surprised to the downside. And added to that was Canterbury earthquake earlier this month which is the worst natural disaster that faces New Zealand in 70 years.This morning the RBNZ downgraded growth forecast until the September quarter of 2011. For the September quarter, the RBNZ cut the GDP forecast to 0.8 per cent from 0.9 per cent and for the December quarter it reduced the forecast significantly to 0.4 per cent from 0.9 per cent earlier.For the March, June and September quarters also it cut GDP forecasts, but increased from December 2011 quarter.CPI inflation forecast was also cut to a peak of 5.1 per cent in the June quarter of 2011 from 5.3 per cent it had projected earlier. The RBNZ, however, warned that reconstruction and restocking may cause inflation to be higher over the coming year than is forecast in the statement.