Bridge officials were waiting to assess the weather forecast before saying for sure that the Presidents Day weekend closure would go forward.
Caltrans spokesman Bart Ney said this morning that the forecast calls for partly cloudy skies, and that the closure will begin as scheduled at 8 p.m. Friday.
"We've got enough time," Ney said. "We'll get it done this weekend.
He said that if things go well, it is "quite possible" that the upper deck could reopen earlier than the scheduled time of 5 a.m. Tuesday.
During the closure, motorists won't be able to drive from the East Bay to San Francisco. However, the lower deck will still be open, meaning drivers can travel from San Francisco to Oakland.
The upper deck will only be closed on the bridge's eastern span, meaning motorists can still drive from Treasure Island to San Francisco.
"We will keep that open for Treasure Island residents," Ney said. The closure will make way for the creation of a detour that will enable crews to complete construction of the bridge's new eastern span.
Currently, on the approach to the span on the Oakland side, the bridge's westbound lanes stand in the path of where the new eastern span's eastbound lanes will be.
The detour will shift westbound traffic south of where it is now, and will allow construction crews to demolish sections of the existing roadway that are in the path of the new incline section.
A video explanation of the new configuration is available online at www.baybridgeinfo.org.
During the closure, motorists are encouraged to take alternate routes or public transit, which will be beefed up with additional ferries and overnight BART service at some stations.
Those who drive should allow extra travel time, even if traveling on other bridges, bridge officials said.