"In light of the downshift in the information this week, we are cutting our second-half growth forecasts further, " Goldman said inside a research note. It was the firm's third cut in GDP estimates within August.
Goldman now expects Gross Domestic Product growth of 1% in the 3rd quarter and 1. 5% in the fourth -- both down from 2% formerly.
"From already quite low growth rates, it appears that the US economic climate is losing further momentum, " Goldman said.
According to its Current Exercise Indicator (CAI), the underlying annual growth rate was about 1. 5% by July, and several major indicators for last month were surprisingly strong.
"However, timelier survey-based data have rejected sharply, and weakness in the hard statistics seems likely to follow having a lag, " Goldman said.
It said that against this "challenging backdrop, " Federal Reserve Chairman Ben Bernanke will deliver an address towards the Fed's annual Jackson Hole Conference next week.
Goldman expects his speech in order to contain three main elements: a discussion of the Fed's dimmer growth perspective, a defense of its past policy actions, and an outline of reducing options, focused primarily on changes in the Fed's balance sheet.
"We see the key reason why Fed officials may prefer to change the composition of the balance linen before expanding it further, and think this could be an important element of the speech, " Goldman said.
"If used aggressively this approach could possess a significant impact, and it may be less controversial. We do not think Bernanke will signal some thing unconventional. ".