Headed out to Grand at midnight. The moon was rising, and red from the lingering smoke. At Grand, due to the hillside, it always takes longer for the sun and moon to appear. The wait was so short that only the top of the water column was illuminated, and because of the backlighting, the water actually looked black, in contrast to the steam. Otherwise it was just another one burst eruption, ending the string of five consecutive two burst eruptions.
At dawn, it was Rift that greeted me. That resulted in a longer than usual interval, and was also a short Rift interval, which is a bad sign.
Another bad sign is when Grand just sits there for no apparent reason and just doesn't want to erupt. That was the case mid-day, which turned into mid-afternoon by the time it did erupt. In this case, there wasn't any sort of heavy overflow or delay or anything, just a series of uninspired pool fills before it finally couldn't hold off any longer. All this is beginning to look like there may be a mode shift in the group.
So just to put all that speculation to rest, or at least make it harder to support, the next interval was less than six hours again. So the obvious guru geyser gazer guess is that Grand is becoming bi-modal.
In any case the fourth eruption of the day was another one burst, this time exactly twelve minutes long.
The day started with a red moon, and ended with a warm, almost muggy overcast. In between, the sky was a dirty brownish-gray color that just made the heat of the day even less appealing.