Cold weather seen chipping away at US economic growth. Reuters

An unusually cold winter and adverse weather may have knocked off 1.4 percentage points from the US gross domestic product (GDP) growth.

The US will put out its first-quarter growth data at 1330 hrs BST.

The American GDP probably grew at a 1.2% annual rate during the January-March first quarter, revealed a Reuters poll of economists. The world's leading economy expanded 2.6% during the October-December fourth-quarter.

US financial markets and Federal Reserve officials are likely to ignore the slowdown in growth.

Fed officials, who have already written off the first-quarter as being hit by harsh weather, are expected to announce a further reduction in the central bank's bond buying stimulus later in the day.

The Fed communique is due at 19:00 hrs BST.

Commerzbank Corporates & Markets said in a note to clients: "While the market is still left in the dark as regards ECB monetary policy the Fed is currently acting as a shining example in predictability - certainly as far as [30 April's] Fed meeting is concerned. The recent economic data is likely to have confirmed Fed expectations. The cold winter meant that the year got off to a weak start.

"GDP is likely to have recorded (annualised) growth of only just 1.0% in Q1, following 2.3% qoq in Q3. However, the data currently available confirms that this period of weakness has been overcome. As a result the Fed will [on 30 April] reduce its bond purchases by a further $10bn to then $45bn per month. It will once again confirm the key rate corridor at 0.00% to 0.25%."

"The communiqué is unlikely to provide any news on the subject of rate hikes either. Moreover there will be no press conference after the decision [on 30 April], during which the Fed Governor [Janet] Yellen could "let slip" any information on the matter. So it would seem that there will be no major momentum for [the US dollar]," the German firm added.

Societe Generale Cross Asset Research said in a note to clients: The FOMC meeting [on 30 April] is likely to be a non-event for the currency and bond markets and the first low-key meeting in a long while. All 43 economists surveyed by Bloomberg expect the Fed to reduce its asset-purchase programme by another $10bn to $45bn/month.

"With no post-FOMC press conference scheduled and the relevance of the so-called "dots" played down by chair [Janet] Yellen a few weeks back, there will be limited takeaway in the accompanying statement to sway the markets to take positions ahead of [2 May's] payrolls data."

"Confirmation of a weak first quarter for the US economy (advance GDP forecast: 1.1% annualised) will most likely be offset by a five-month high for ADP employment (SG forecast: +220k)," the French firm added.