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Observations for 2021 May 18


At Norris, not much change from yesterday. The weather was nice, so ended up spending about seven hours there to confirm that there was no progression in New Crater/Steamboat's activity.

Back in the Upper Basin, the evening Grand was going to be around the same time as yesterday's evening eruption. This time, the sky was clear, but it was windy. Arrived on what appeared to be a poor fill, with a short Turban eruption duration. This usually is what happens on the eruption after a Delay.

For the next Turban eruption, there seemed to be another poor fill, but around the 22 minute mark, Grand rose up and started having small waves. This lasted for about seven minutes, when just as abruptly, the pool began dropping. The Turban eruption interval was almost 36 minutes.

But two Turban intervals later, the fill proceeded nicely into an eruption. Last night the rainbow was behind Grand, today Grand provided the rainbow, at least from our perspective. Around the ten minute mark, Grand went into Big Sawmill mode, and that lasted another 90 seconds.