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Concern is emerging about a slowdown in the recovery of the US economy which will cause the Fed to hold interest rates lower for longer, adding to the upwards pressure on the New Zealand and Australian currencies.
Craigs Investment Partners broker Chris Timms said the first of the reports - the first estimate of economic growth for the three months ended March - was expected to reflect extensive weather-related disruptions to output.
Markets expected an annualised reading of just 1.1% of economic growth, well below the 2.6% posted in the final quarter of last year.
''Most economists see this rebounding strongly in the current quarter, so a weak reading will largely be put down to the effects of the weather.''
With GDP being reported about 1am New Zealand time, the next piece of information would be the conclusion of the Fed meeting at 6am, Mr Timms said.
There was no press conference or update of economic projections for the meeting, although the following day Fed chairwoman Janet Yellen was scheduled to give a speech that might provide insights into any change in view.
The Fed was expected to taper its its quantitative easing (QE) programme by another $US10 billion ($NZ11.66 billion) a month which would take QE to $US45 billion a month, down from $US85 billion for most of last year, Mr Timms said.
Westpac chief economist Dominick Stephens said the Fed's market committee was more circumspect last month on current economic momentum, but remained resolute in its expectations about the outlook.
Since then, Fed communications had remained consistent with the thesis that barring a material downside surprise on the economy, the tapering process would continue in measured steps in coming months. The next step would be a further $US10 billion reduction.
''As is clearly apparent from the tone of available partial data, the likely outcome for first quarter GDP, and the absence of activity in the housing sector, underlying momentum is poor. That said, the Fed's preference is [to] continue tapering, and keep rates unchanged for as long as possible.''
The April Institute for Supply Manufacturing (ISM) factory survey was likely to show a slowdown relative to where the economy was at in the second half of last year, Mr Stephens said.
The US April jobs report, due out early on Saturday, might provide good news, Mr Timms said.
In March, 192,000 jobs were added and the consensus for April was for 220,000 jobs to be added.
''There is some potential for an even better number than this, when we consider the four-week average of initial jobless claims hit a post-recession low for the week the April jobs survey was conducted.''
In New Zealand, building consents are due out tomorrow, as are some measures of business confidence.
Westpac is forecasting a 4% rise in March consents.
Falling house sales in recent months would ordinarily be a red flag for a drop in building activity, but Mr Stephens said there were two factors which suggested the wedge would persist: the necessity of the Christchurch rebuild and the Reserve Bank's restrictions on high loan-to-value lending which had dampened turnover but not the underlying demand for dwellings.