If you read Dennis' <a href=http://www.whitneyportalstore.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=005127>weather report on this board</a>, you will see that winds should peak on Friday, and the weekend will be breezy. Since you are going over the weekend, you ought to be ok.
But even if you are there during the peak winds, the gusts could knock you down, but not blow you away. I have found that in strong winds, you might lose your balance, but your natural response is to crouch down and hit the ground. If this happens, you only move several feet. You won't be literally blown off the trail.
For more weather links, including the NOAA site, see the weather link on the Whitney Portal Store main page (link at the bottom of this page), or go directly to it here:
Whitney weather links.__________________________________
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Mt. Whitney Hikers Association ----