The forecast puts the probability that the launch will take place as planned on Friday at 80%, a 10 point improvement from previous days, the Atlantis STS-117 mission weather officer said.
Meteorologists have warned that Cape Canaveral and the Atlantis launch pad at the Kennedy Space Center may face some adverse weather in the coming week, including hail and gusty winds of up to 60 mph.
NASA can continue efforts to launch the Atlantis until June 12, when it will have to give way to an Atlas-5 launch vehicle carrying a spy satellite. The next launch window, starting June 17, will last until mid-July. If the launch planned for June 8, 7.38 p.m. local time (11.38 p.m. GMT) fails within five minutes, it will have to be delayed for at least 24 hours.
The 11-day eight-member mission, commanded by Col. Rick Sturckow of the U.S. Marine Corps and piloted by Col. Lee Archambault of the U.S. Air Force, will help build new segments of the International Space Station.
The STS-117 mission was originally planned for March 15 but the shuttle had to be pulled back because the external fuel tank was damaged by hail.