Just before the Boulder Field I ran into Becca, Tam, and Chris. They had started 2 hours before me at 6:30am but Chris was starting to move slower at this point so Becca and I headed up to the Keyhole ahead of them. In the Boulder Field I took a compass reading linking the Keyhole and Granite Pass in case we had to come down in a whiteout. After waiting ~30 min in the shelter, we could see rain/snow falling on the horizon and we were eager to continue up. We couldn't see Tam and Chris in the Boulder Field (but we later found out they saw us looking for them) so we left them a note (scrawled into the top of a Gatorade bottle) in the hut and continued to the summit. The Trough was full of new soft snow. By the time we reached the Homestretch, we could see storms in 3 different directions, heard thunder 3 times, and saw lightning once. But hey, we were only 150 feet from the summit, so we dashed up, took the obligatory summit photos, and descended. It was pretty cool to have the summit to ourselves but we didn't want to stay long. It started snowing from the bottom of the Homestretch to the middle of the Trough so we were eager to make it back to the Keyhole before conditions worsened. Luckily the snow soon stopped and it brightened up again after the Trough. There was enough snow in the Trough that we just did a seated glissade all the way down using our hands and feet as brakes. I only had Lycra cycling gloves and wanted to keep them dry so I just used my bare hands - it was pretty cold. My nylon pants dried quickly once I started walking again.
When we got back to the Keyhole we were surprised to find Tam and Chris in the hut! It turned out that Chris' feet were bothering him and he had laid down for 1+ hours in the Boulder Field earlier. We ate some snacks and then descended. The weather for the descent was beautiful: about 60°F with little wind. We stopped many times so Chris could rest his feet but once we were out of the Boulder Field it really didn't matter how long it took. We didn't get back to the trailhead until 9:13pm.
In the end, it was a nice hike (mostly class 1 with limited and fairly tame class 3) with only little bits of snow and ice (outside of the Trough which was filled with snow). I never broke out the axe or crampons and my non-waterproof boots stayed dry the entire time. I counted 10 people that made the summit but there may have been more since I didn't talk to everyone hanging out at Granite Pass. I'm not sure if the NPS had classified Longs as "unknown winter technical" this day but only hiking gear and a little luck with the weather were needed for wonderful views with snow. Overall, a very memorable hike :-)