The Atlanta Fed GDPNow tracker fell to -1.6% from -1.5% after today's housing starts data.
"After this morning's housing starts report from the US Census Bureau, the nowcast of second-quarter real residential investment growth decreased from -8.8 percent to -10.1 percent," the release said.
The final update is on July 27 ahead of the first release on Q2 GDP a day later. Expect the focus to shift to GDP after the FOMC.