President Donald Trump speaks about the economy on the South Lawn of the White House on July 27, 2018, in Washington, DC.

Economic growth is expected to continue at a rapid pace in the third quarter, according to a preliminary forecast from the Atlanta Fed.

The central bank district estimates that GDP will increase 5 percent for the July-to-September period, according to an update posted Wednesday.

If the forecast is accurate, it will come on top of a strong 4.1 percent second quarter that was buoyed by a jump in consumer and business spending. President Donald Trump boasted Friday that growth would go "a lot higher" even though many economists, including at the Fed, expect the economy to moderate in 2019 and beyond.

The Atlanta Fed's GDP Now forecast, however, has its skeptics. The tracker often starts off optimistic early in the quarter then cools as more data flow in. In the first quarter, the indicator at one point showed 5.4 percent growth in a quarter where GDP rose just 2.2 percent.

The model has proven to be particularly sensitive to the ISM manufacturing report, which came out Wednesday morning.

Though the July reading of 58.1 actually was below Wall Street expectations of 59.5, the Atlanta Fed said the internal numbers showed that real consumer spending and real private fixed investment accelerated enough to warrant expectations that overall growth would be higher as well.

Prior to the report, GDP Now had been indicating growth of 4.7 percent