Observations for 2019 May 20
It was back to Norris. We left Old Faithful with it snowing, and it continued all through the drive. We arrived on the platform at 07:15, where the wait began.
For the next eight hours, it was pretty quiet. There were occasions where the strength of a surge was worthy of noting. There were a couple at 08:03 and 09:35, but no followups. That was it until couple more at 13:42 and 14:21. Again, it briefly looked good to a number of us, but nothing else happened.
The conditions were for the wait were poor. The snow continued off and on for the first few hours. Finally the clouds broke and there was even some warmth from the sun which dried things out. But sleet started around 13:00, and that turned into rain, which persisted for about an hour. The little wind we had was blowing toward the platforms, which made observations difficult, especially for the south vent.
So by 15:13, it was pretty damp, and cloudy, but no precipitation. There were a couple of quick surges that got my atttention, so much so that after a third one, I dug out the camera to start recording.
I got two minutes leading up to the start of the eruption. The surges were coming several a minute by then, and there were two huge ones in the seconds before the start. As the water climbed, rocks could be seen falling next to the column. The column itself was lost against the gray sky backdrop. But the upper platform was pelted by what seemed at first to be hail. It turned out it was gravel ejected by the eruption.
Because of the wind direction, none of the water fell upslope from the north vent. That's probably why the water columns never turned brown, and also probably why the water phase lasted at most three minutes. I noticed the vents in loud, strong steam at the 3m45s mark, although the north vent would could occasionally be seen throwing water later on.
Also because of the wind direction, there are new runoff channels being developed all down the slope between the main runoff and Cistern. I got down to the bridge before any footprints appeared in the mud washed over the walkway, and there was rocks all over the bridge, and some fairly big ones (cherry tomato sized) too.
The wind kept shifting, but the rain was localized, so at times one or the other platform, or part of the walkway, was being drenched, while the rest of the area was not. At one point, as I was moving stuff back to the parking lot, I even got rained on near Emerald. Even so, everything got drenced, and the blankets we were using to keep warm can hold a lot of water in them. The parking lot, however, never seems to have been a target, so this eruption was a lot like the first one seen last May.
Later that evening, Suzanne noted that Grand had been having a long series of sub-five hour intervals, and we were approaching the five hour mark. So we went out at sunset to see a couple of Turban intervals. The second one didn't officially qualify as a Delay, but was close enough. And since it was after sunset, we didn't stick around in the windy cold. Turns out it was a Two Turban Delay, and we made the right decision.