As of Sunday, 6/6, the forecast is talking about only a 20% chance...sounds like typical afternoon t-storms.
Your best bet is to get a very early start (be on the trail at first light, before 05:30) and be off the summit well before noon.
We've dodged t-storms on several trips to various mountains, including Whitney in 2001 (see trip report under the "highpointing" section of my <a href="http://www.mtritter.org">WWW site</a>), when we summitted about 10:30 or 10:45 and beat a hasty retreat a half-hour later, with threatening conditions on the way back from the summit to Trail Crest and then more weather as we made our way back down the switchbacks.
The key is to watch for developing clouds and clear out before they gather and rise enough to start lightning.