The American economy is expanding at a 4.1% annualized rate in the second quarter, according to the Atlanta Federal Reserve’s GDPNow model.

Domestic factory production grew 1% in April, the largest monthly gain in more than three years, according to government data released Tuesday. Housing starts declined 2.6%.

The forecast for residential investment growth rose to 8.3 percent from 6.0 percent. The forecast for final sales to private purchasers climbed to 3.6 percent from 3.3 percent. Inventory investment is forecast to grow 1.2 percent from 1.0 percent. Much of the inventory growth was concentrated in motor vehicle and parts dealers.

The Atlanta Fed’s GDPNOW provides a real time look at the U.S. economy prior to the release of the official estimate of gross domestic product.