Observations for 2019 July 30
Arrived at Norris at 05:30. it was foggy the whole way, as it had rained during the night, and there was still some lightning visible to the north.
An hour and a half later it was still overcast and foggy, and I hadn't yet gotten around to digging something to eat out of the pack. It was at 07:12 that we got a long, strong and sustained minor. That got me to put away things and wrap up the pack in its rain cover. The heavy surging continued, so next it was time to get the chair and pack out of the way.
The activity continued, and based on our experiences of the past year or so, it quickly became obvious that this was what we'd been waiting for. In the next few minutes we got stronger and longer play than all day yesterday (or the day we waited last week, or the three days Memorial Day weekend). Finally there was a surge that kept building and climbing, until it became obvious that each burst was higher than the last.
It quickly became apparent that there wasn't going to be a chance to see much of the water phase. I'd would have liked to try for a height measurement, but after about a minute realized that there was something else I could do. I moved quickly (more of a trot than a run) down the switchback and past Cistern and over to the runoff bridge, with the video recording the whole way.
If any water washed over the bridge, it was brief and didn't leave much dampness. Otherwise the two main runoffs were pretty impressive, more than I'd seen before. (Those times were well into the steam-phase, too.) Coming back I saw the start of water coming down all the runoff channels that run under the switchback walkway.
The water coming from North Vent seemed gray, but not reddish or brown.
Standing on the upper platform, I realized that it would make a lot more sense to get the tripod and the other phone and set it all up to try and record any chokes from before the start, rather than trying to react to what the geyser was doing. Sof went back down to where my pack was, and of course the first choke happened as I was trying to dig everything out. But I did manage to catch the next three, as well as another one on my regular phone. There were a total of eight, and I'd have gotten some more if somehow the phone hadn't gotten into "slo-mo" mode. A rant on how phone camera interfaces are overloaded with useless gimicks and poorly designed for use outside in bright light might be appropriate. (For most people, it appears a button labeled "Selfie! Me!" would suffice.)
Telling when there was going to be a choke seems to depend on noting the activity of the wall of rock north of the North Vent. If there is heavy water landing there and running over the edge creating waterfalls, North Vent will start chugging, and eventually choke. If the wind is shifted, say toward a platform, then the steam coming from North Vent is continuous, and there won't be a choke.
The corridoned off area of the platform only appeared to have one or two small rocks on it that weren't there when we arrived in the morning. (I was tempted yesterday to put a huge rock or two in that area, just to get a reaction...) A small rock did land next to me there, but it someone made it back onto the ground.
By the time we left, at around 10:10, Cistern had dropped below overflow, but because none of the runoff made it into the feature, it was still clear blue.
Out to Grand for the afternoon One Burst Eruption. Arrived to find Rift marker gone and West Triplet down much more than during the past week. An hour later I saw the first eruption of West Triplet I was aware of since 22 July. The only eruption of Sput D I saw was during West Triplet, and it was accompanied by Percolator, another geyser not seen in a week.
Grand itself had to have a two Turban interval delay, followed by a Turban start. The eruption was a little over ten minutes long and Vent & Turban continued. While waiting a dark, ominous storm cell passed north, through the Lower Basin, but was never really a threat here.