http://www.geo.fu-berlin.de/met/ag/strat/produkte/qbo/qbo_wind.jpg
I'm not 100% certain of the full definition of a westerly qbo, but the above (found here: http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/) would indicate that a westerly phase has already started at the top of the strat.