Felt very lucky to have won a permit for Sept 2-4. Left Whitney Portal on the 2nd @ 8:30am with sights on Trail Camp. Made it a little above Mirror Lake before being pelted with hail and rain about 10:30ish. Briefly contemplated continuing on to Trail Camp, but a thunder clap decided our dilemma and we returned down to Outpost Camp. With thunderstorms in the forecast for our summit day (9/3), we decided to get an early start and hopefully get back below the switchbacks before any t-storms developed. Left Outpost Camp at 2:30am and made it to Trail Camp about 4:15. (I was not moving very quickly in the dark.) Filtered water just before the 1st switchback. Began the switchbacks at 4:30. They were not that bad and there really are 97 (or 99 if you count the two that half turn.) Yes, I actually counted! Reached Trail Crest at 6:10. Hung out there and watched a very beautiful sunrise! Left Trail Crest at 6:30ish and reached the summit at 8:15. (There still was a small 20 foot snow patch a little below the summit.) What an absolutely beautiful clear morning - not a cloud in the sky. Hung out at the top until 9:40 and hated leaving - but have always heard how quickly weather can change in the mountains. Since an uphill was coming and the sun was beating down on us, we stopped at the JMT intersection to remove our jackets and apply sunscreen. Only a few minutes later we arrived at Trail Crest and were greeted with a fairly large gray/black mass of clouds to the immediate East. (It was just after 11am.) Knowing we needed to get down low asap, we picked up the pace and reached Trail Camp in 50 minutes. The black clouds that decorated the sky above us continued to grow and become more and more ominous. (What I cannot understand is how with t-storms seemingly about to occur, people still continued to begin to climb the switchbacks with intentions of summiting.) We continued our race towards Outpost Camp, but did not quite succeed in outpacing the t-storm as it began to hail just as we passed through Trailside Meadow. Rain/hail did not let up and the trail/rocks became quite slippery and slowed our pace. We did finally reach Outpost at around 1:30pm and dove into our tents to get dry and sleep. Rain, lightening and thunder continued for over 4.5 hours! It was a bit unnerving where we were at - can't imagine what it was like to be up at Trail Camp or higher.

A few notes:
Acclamation: Camped at East Fork/Rock Creek Lake area (9,000+). Hiked out of Mosquito Flats trailhead (10,000) over Mono Pass (12,000)to a ways above Summit Lake.

Water: Carried 3.5 liters from Outpost Camp and topped off at Trail Camp. Drank often. Used it all!

Food: Ate small snacks at least every 30 minutes. Also ate electrolyte tablets every hour or so.

None of us had any altitude symptoms. I believe that acclimating ahead of time; stopping to eat and drink water often during ascent - even when we didn't want either thing; and deep breathing all helped. Also, took 400mg ibuprofen at start.

This forum was so helpful in the planning of this trip. Thank you so much to all the posters.

Mt Whitney is an absolutely beautiful and magical wonderland!