geysers.org

Didn't get much sleep during the night, as I was busy documenting and editing and uploading videos. When the video upload process showed it was going to take over 200 hours, I knew I needed to make the file a bit smaller. Five hours was much better, and it probably took less, as it was available to post during the night

By then it was getting light outside, so might as well head out to Grand, which was approaching 14 hours since the previously seen eruption. But first, I headed back to the Bijou Cage to document the locations of the various signs.

Finally got to Grand, just in time to catch the start of a West Triplet eruption. That was followed by a Turban Delay Interval, one where the heavy runoff didn't start until the 30 minute mark. The interval was so long that Rift started during the Turban eruption.

The West Triplet eruption lasted almost exactly an hour, and about a half hour later, Grand filled nicely on a long Turban eruption interval that resulted in a One Burst Eruption.

2026-Sep-11 : 08:50:53 D3/G1Q

 08:50:51	Boop	-0m02s
 08:50:53	B1	--- d=10m42s
 08:50:54	Vent Ovfl	0m01s
 08:51:05	Turban	0m12s
 08:54:13	Vent	3m20s
 09:01:35	P1	10m42s
 09:02:29	V&T Quit	11m36s

				     	ΣD=10m42s
	* * * * *
 07:13:20			d=04m22s	
 07:17:12	West Triplet
 07:50:30	Int: 37m10s	d=04m55s D0	
 07:54:07	Rift
 08:09:19	Int: 18m49s	d=02m30s D1	
 08:28:56	Int: 19m37s	d=04m07s D2	
		      Grand: 21m57s

Tried to wait for Beehive after that, but it was so windy and miserable that most of the people waited decided to let someone else stay there. Which was why it appears that no one actually saw the start of the eruption of the Indicator, as everyone had left. The Beehive eruption was still nice, despite the wind.

At that point, there wasn't much to do around the basin, which meant it was a good day to take care of various housekeeping chores which had been postponed due to the waiting in the Bijou Cage.

Got back out to Grand just after the six hour mark. Immediately got a Turban Delay Interval eruption, which meant it was going to be a bit of a wait. Seven turban eruption intervals later, we got a second Delay Interval. By that time, it was getting stormy to the north, and the wind was making the whole wait as miserable as one on Geyser Hill. By this time, it had been over three hours without any activity from West Triplet. An hour later West Triplet started to erupt, but finished within a couple of minutes.

That seems to have been sufficient activity to qualify for the opening of the West Triplet window, as Grand finally erupted 20 minutes later. Grand's pool was full and having waves at the 13 minute mark when Turban started. Turban started out slow, then suddenly began acting like it does when Grand erupts. The second burst consisted of over two minutes of some of the smallest Big Sawmill activity I've seen in quite a while. Grand repeatedly looked like it was stopping, only to boil up a few meters high, then have some small jets.

2026-Sep-11 : 19:17:53 D7/D5/T2*Q

 19:17:20	Turban	-0m33s
 19:17:23	Vent Ovfl	-0m29s
 19:17:47	Boop	-0m05s
 19:17:53	B1	--- d=08m06s
 19:20:04	Vent	2m11s
 19:25:59	P1	8m06s d=18s
 19:26:18	B2	8m25s d=02m45s
 19:29:04	P2	11m10s
 19:30:04	V&T Quit	12m11s

				     ΣB=10m52s	ΣD=11m10s
	* * * * *
 15:02:04			
 15:35:03	Int: 32m59s	d=03m42s D0	
 15:51:56	Int: 16m53s	d=03m09s D1	
 16:09:40	Int: 17m44s	d=02m56s D2	
 16:26:33	Int: 16m53s	d=02m45s D3	
 16:46:07	Int: 19m34s	d=02m57s D4	
 17:05:42	Int: 19m35s	d=03m01s D5	
 17:22:23	Int: 16m41s	d=02m57s D6	
 17:55:01	Int: 32m38s	d=03m30s D7/D0	
 18:11:19	Int: 16m18s	d=03m04s D7/D1	
 18:29:24	Int: 18m05s	d=03m30s D7/D2	
 18:45:39	Int: 16m15s	d=02m56s D7/D3
 18:55:35ns	West Triplet d=02m13s
 19:04:10	Int: 18m31s	d=03m07s D7/D4
		     Turban: 13m09s

Once again I got to walk up on a Turban Delay Interval, this time 14 hours after the eruption we saw the day before. Tuns out the interval wasn't horrible, and the Delay was only for three Turban eruptions.

That's when we got a nice steady fill in Grand, then a full pool with waves increasing in strength. The start was explosive, and Turban didn't start for nearly a minute. Even though the first burst lasted more than nine minutes, we got a second burst.

Midway through the first burst we started getting radio calls from the Bijou Cage announcing a Bijou pause where Feather was pulsating and overflowing. It made for a significant distraction from Grand's eruption.

2026-Sep-10 : 09:04:35 D3/G2Q

 09:04:35	B1	--- d=09m07s
 09:05:30	Turban	0m55s
 09:08:33	Vent	3m58s
 09:13:42	P1	9m07s d=48s
 09:14:31	B2	9m55s d=38s
 09:15:09	P2	10m34s
 09:15:52	V&T Quit	11m17s

				     ΣB=09m45s	ΣD=10m34s
	* * * * *
 08:06:37			d=04m34s D0	
 08:23:42	Int: 17m05s	d=03m59s D1	
 08:41:25	Int: 17m43s	d=03m43s D2	
 09:19:15	West Triplet
		      Grand: 23m10s

Afterwards, Castle started to erupt, and when it didn't turn into a minor eruption, I waited around to watch the major eruption transition into steam.

Returned a few hours later to the Bijou Cage. Nothing much had happened since the last Bijou pause. On the Giant Platform, nothing much happened for the next 3-1/2 hours that I was there. Occasionally we'd get a Mastiff back vent surge followed by water just visible in Mastiff, other times just the Mastiff surge.

Midway through this wait, I glanced over to the south, and noticed a lot of steam coming from Oblong. It was windy, so the steam wasn't rising above the trees, but instead extended to the left over the river. We were seeing the first eruption of Oblong in several days.

I headed over to Grand when its eruption window opened, and saw some Turban eruptions. The third turned into a Delay Interval, and when Turban finally erupted, I turned my attention to tying down my camera tripod, which had moments earlier tried to fall over because of the wind. So I was distracted when Grand started to erupt 1-1/2 minutes later.

Around the 8-1/2 minute mark, there was a false pause and long slowdown in Grand. I figured it was going into Big Sawmill mode and we'd get only a single burst. Instead, after a half minute, Grand quit, and we got a second burst.

2026-Sep-10 : 16:41:05 D0/T2Q

 16:39:37	Turban	-1m28s
 16:41:05	B1	--- d=08m53s
 16:43:18	Vent	2m13s
 16:49:28	FP	8m23s
 16:49:58	P1	8m53s d=19s
 16:50:17	B2	9m12s d=48s
 16:51:05	P2	10m00s
 16:51:51	V&T Quit	10m46s

				     ΣB=09m41s	ΣD=10m00s
	* * * * *
 15:32:04			
 15:50:45	Int: 18m41s	d=03m17s	
 16:06:54	Int: 16m09s	
 16:48:21	West Triplet
		     Turban: 32m43s

After that, it was back to the Bijou Cage. By this time, it had been seven hours since the last Bijou pause. The only time a length of time like that, without a pause, had been seen had been just before the previous Giant eruption. So it was time to prepare for a long wait. After an hour and a half, I made a quick trip back to the cabin to reconfigure for a nighttime wait.

All during this wait Mastiff would have a surge every 30 minutes or so. Most of the times, Bijou would roar and Catfish splash about three or four minutes later.

Finally, just after 21:00, we got the first Bijou pause in eleven hours. It took a while for Mastiff to show water, and the event proceeded as a Standard Bathtub until Feather filled and started to push water at about 4-1/2 minutes. Almost immediately, Feather started to erupt, and Mastiff overflowed. This was unlike any activity seen since 2018. At this point, the Hot Period behaved much like those of that year. One by one, various vents started to show activity, and Giant began to surge more powerfully.

Ten minutes after Bijou had paused, Bijou began to roar as Mastiff dropped. A minute later, Giant erupted.

I was in the Cage near the benches, and got soaked repeatedly by hot water and hot steam. I made a hasty exit, leaving my pack behind. There were multiple bright lights, so the eruption was easily visible. Ben Vanderlay got a height at the start of 215ft.

As the eruption progressed, more and more people began to appear on both the walkway from Oblong and along the bike trail. At least one NPS vehicle drove down the bike trail, and by then there was a crowd of 30-40 people gathered in the Cage and along the boardwalk.

I recorded the entire start of the Hot Period and most of the Giant eruption, until the battery was drained, for about an hour of video. The timestamps on the Hot Period portion show most of the activity matching the times in my notes. Once the eruption started, the video doesn't show much, because the wind was blowing steam and spray toward the camera, and it seems the camera had a hard time processing what was going on, especially with the sound.

The video is available in a separate posting. It only took 5 hours to process and upload it from the cabin.

21:02:54	Mastiff surge/Bijou pause
21:04:30	Mastiff water visible
21:05:02	SW spits
21:05:12	Catfish splashes
21:06:25	SW vents erupting
21:06:59	Feather water visible
21:07:34	Feather push
21:07:48	Mastiff in overflow
21:07:57	Feather erupting
21:08:13	Mastiff front boil h~1m
21:08:48	Feather Satellite erupting
21:09:21	Catfish splashing
21:09:28	Cave erupting
21:10:10	Bijou erupting
21:10:41	Giant surging
21:11:59	Rust eruption?
21:12:43	Giant surging to top of cone
21:13:04	Bijou roaring
21:13:20	Emerald erupting
21:14:06	Giant start of eruption

22:03:36	Feather restart
22:05:03	Feather Sat. restart
22:17:45	Giant last water seen
22:33:09	Grotto ie

This morning it was Grand in eruption as I arrived at Castle. It was foggy, so I could only hear the eruption. Went over and arrived at Rift just in time for the One Burst Eruption to end. West Triplet was in eruption, also. It must have been near the start, as it was reported in eruption again an hour later, with Rift also erupting.

This morning it was Grand in eruption as I arrived at Castle. It was foggy, so I could only hear the eruption. Went over and arrived at Rift just in time for the One Burst Eruption to end. West Triplet was in eruption, also. It must have been near the start, as it was reported in eruption again an hour later, with Rift also erupting.

Returned later to the Bijou Cage. For hour-and-a-half we didn't see anything happen, although Feather appeared to be full and just below overflow. Then we got a large Mastiff surge followed by splashing in the Southwest Vents. Feather did overflow slightly during this time, and the Southwest Vents put out enough water to fill the depressions surrounding the vents and to start flowing down the front slope. The water level in Mastiff rose to about the highest I've seen yet, down maybe 10cm. But Bijou never paused, but did roar after Mastiff dropped.

Another hour-and-a-half later with nothing happening at Giant, I transferred over to Grand. Immediately I got to experience a Turban Delay Interval. Two Turban intervals later, there was a second Delay Interval. After another hour, West Triplet finally erupted, but finished erupting with no associated Grand eruption. On the eighth Turban eruption after the second Delay Interval, we got a third.

It took four more Turban Intervals before we finally got the One Burst Grand eruption, for an interval of over eleven hours. West Triplet started another eruption during Grand, exactly three hours after the previous eruption.

2026-Sep-09 : 17:26:54 D2/D8/D4/T1Q

 17:26:38	Vent Ovfl	-0m16s
 17:26:45	Boop	-0m09s
 17:26:53	Turban	-0m01s
 17:26:54	B1	--- d=10m42s
 17:28:56	Vent	2m01s
 17:37:36	P1	10m42s
 17:38:34	V&T Quit	11m40s

				     	ΣD=10m42s
	* * * * *
 12:46:58			d=04m08s D0	
 13:03:48	Int: 16m50s	d=03m44s D1	
 13:36:07	Int: 32m19s	d=03m59s D2/D0	
 13:52:12	Int: 16m05s	d=03m46s D2/D1	
 14:11:03	Int: 18m51s	d=03m51s D2/D2	
 14:30:17	Int: 19m14s	d=03m44s D2/D3	
 14:34:08	West Triplet d=03h00m
 14:47:04	Int: 16m47s	d=03m22s D2/D4	
 15:06:58	Int: 19m54s	d=03m36s D2/D5	
 15:23:35	Int: 16m37s	d=03m55s D2/D6	
 15:39:40	Int: 16m05s	d=03m03s D2/D7	
 16:11:10	Int: 31m30s	d=04m02s D2/D8/D0	
 16:29:11	Int: 18m01s	d=02m22s D2/D8/D1	
 16:44:56	Int: 15m45s	d=03m36s D2/D8/D2
 17:03:20	Int: 18m23s	d=03m47s D2/D8/D3
		     Turban: 23m32s

Did go back out to the Bijou Cage at sunset, and again spent two hours seeing nothing much happen, when prior to my return there had been a couple of Bijou paused observed.

I woke up at 05:45 with the intention of going out to Grand if it hadn't erupted, or going back to sleep. Didn't feel a need to go to the Bijou Cage as there were others who were out and about that early. I started to get ready, then saw a webam report of Grand in eruption at 05:50. So it was get unready and sleep in for a few more hours.

Did get out to the Cage around 09:30, after making breakfast. Spent a couple of hours there, and saw first a Mastiff Bathtub where Bijou didn't shut off. The surging from Mastiff at the start was at least two meters high.

Then almost two hours later there was another Mastiff fill without Bijou stopping, this time with some Feather overflow. At that point it was time to head to Grand.

At Grand, the first Turban interval I saw was a Delay Interval lasting over 35 minutes. Between the following fourth and fifth Turban eruptions, I saw a single splash from West Triplet. Then minutes later, after the fifth Turban, West Triplet started a real eruption. This time Grand followed up with its One Burst Eruption. After Grand erupted, I waited to see if West Triplet would be followed by Rift, and it was.

2026-Sep-08 : 14:36:40 D6/G1C

 14:36:37	Boop	-0m02s
 14:36:40	B1	--- d=09m43s
 14:36:53	Vent Ovfl	0m13s
 14:37:15	Turban	0m34s
 14:39:54	Vent	3m14s
 14:46:24	P1	9m43s
Vent & Turban continue

				     	ΣD=09m43s
	* * * * *
 12:10:28			
 12:45:37	Int: 35m09s	d=04m20s D0 Boop: 12:41:29	
 13:02:49	Int: 17m12s	d=03m05s D1	
 13:19:51	Int: 17m02s	d=02m51s D2
 13:37:06	Int: 17m14s	d=03m19s D3
 13:56:49	Int: 19m43s	d=03m34s D4	
 14:09:30	West Triplet
 14:16:39	Int: 19m50s	d=03m33s D5
 14:20:28	West Triplet
		      Grand: 20m00s

In the process of heading back to the Bijou Cage, I heard the radio call for Beehive's Indicator. It was a cool, sunny and windy day, and there was already a crowd on Geyser Hill thanks to an eruption of Old Faithful that had just ended. I watched the eruption from the bike trail between Lower Ham's and the Inn parking lot. The wind shifted a couple of times, and the screams of the people being inundated could easily be heard over the wind noise. Beehive itself was barely audible.

Back at the Cage, nothing much happened for about 90 minutes. Finally we noticed Bijou slowing down, then completely off, before Mastiff began some large surges. After about a minute, the Southwest vents spit a couple of times, so it appeared that we were going to get another Standard Bathtub. Then water became visible in Feather and the Southwest Vents began erupting from three vents and putting water down the slope and filling nearby puddles. The roaring from Bijou at the end seemed stronger than usual, too.

Went back out to the Cage before sunset. As far as is known, nothing had happend since the earlier event. Stayed out until midnight, and during that time there were only two minor events. In both cases, four hours apart, Bijou never shut down, and in the dark, we couldn't see water level in Mastiff. We only knew of the end when Bijou started to roar.

Was not originally intending to wait that late in the Cage. Instead intended to go to Grand around the 7-1/2 mark. Instead we saw the large steamcloud of Grand around the 6h45m mark (2130ie).

At one point in the Grand wait, there was some applause at the end of an eruption of Turban. I looked over, and it was a group of about five young men. They then got up and left, speaking what I believe was German as they passed me. From that, I assume that their applause was supposed to be ironic, and they thought Turban was actually Grand.

Once again it was out to the Bijou Cage at dawn to see what had transpired overnight. It wasn't possible to tell, as it had rained a few hours earlier.

The day started out cold and overcast and blustery, and by mid-morning was cold and sunny and blustery. Probably the most unpleasant day so far this visit.

In the Cage, there was a Standard Bathtub shortly after I arrived, and there was another about an hour later. All through the day the occurred one to two hours apart.

At Grand, there was a nearly ten hour interval, this time without a Turban Delay Interval. The whole time West Triplet was quiet, but West Triplet began erupting during the Grand eruption, which like yesterday's long interval eruption, had two bursts.

2026-Sep-07 : 14:21:28 G2Q

 14:21:20	Vent Ovfl	-0m08s
 14:21:24	Boop	-0m04s
 14:21:28	B1	--- d=08m18s
 14:21:37	Turban	0m09s
 14:24:25	Vent	2m57s
 14:29:46	P1	8m18s d=47s
 14:30:33	B2	9m05s d=57s
 14:31:30	P2	10m02s
 14:32:28	Drain	11m00s
 14:33:06	V&T Quit	11m38s

				     ΣB=09m15s	ΣD=10m02s
	* * * * *
 10:39:47			
 10:56:25	Int: 16m38s	d=03m14s	
 11:15:09	Int: 18m44s	d=03m38s	
 11:33:41	Int: 18m32s	d=03m21s	
 11:53:04	Int: 19m23s	d=03m46s	
 12:13:25	Int: 20m21s	d=03m14s	
 12:33:38	Int: 20m13s	d=03m53s	
 12:51:25	Int: 17m47s	d=03m04s	
 13:10:26	Int: 19m01s	d=03m48s	
 13:30:07	Int: 19m41s	d=03m11s	
 13:47:30	Int: 17m23s	d=02m59s	
 14:04:29	Int: 16m59s	d=03m07s	
 14:27:05	West Triplet
		      Grand: 16m59s

Later sessions in the Bijou Cage yielded some Standard Bathtubs and an event where Mastiff showed water but Bijou never shut off. It's looking like things at Giant may have stabilized, which means either no eruption for a while, or an eruption getting ready.

Decided it was a good night to not go out to Grand until later in the window. So I was at Crested Pool when the 7-1/2 hour interval One Burst Eruption started. West Triplet was also in eruption by the end of Grand's eruption.

2026-Sep-07 : 21:49:04ns 1C

 21:49:04	B1	--- d=10m23s
 21:59:27	P1	10m23s
Vent & Turban continue

On the way back last night, in the dark I noticed large puddles of water near my cabin. Steaming puddles. It seems a new hot spring broke out next to Cabin #230 across from us, and was flooding the area. Because of this, the cabin area had no hot water until the repairs were done today.

Last night's fiasco seems to have shifted Grand into a mode where it will have only one eruption in good daylight, and two in the dark or without sun. But it was a bit of a relief to see that because it erupted about the time I woke up, I wouldn't need to wait for it.

Arrived at the Bijou Cage as it was starting to get light. It was also quite foggy. At times difficult to see if Bijou was actually erupting, so had to go by sound. Waited well over an hour and a half with only some good sized Masfiff surges. Shortly after Rocket had a major eruption we finally got a 3m00s Standard Bathtub, with some water visible in Feather and a bit more splashing that usual from the Southwest Vents.

A Standard Bathtub consists of a large surge from Mastiff's back vent, followed by a pause by Bijou. This pause lasts about three minutes, give or take twenty seconds or so. A different length is notable. Water in front Mastiff rises to about 10 to 20 cm below the rim for most of the pause. The Southwest Vents will spit briefly. After Bijou restarts, Catfish and the B-C Vent will also splash, and then Bijou will have a brief period of roaring. This behavior was fairly consistent before the last eruption, and has been common since.

Returned to Grand with the expectation of an afternoon eruption. After about an hour and a half, there was the first documented Giant Hot Period, with a short eruption of Feather Geyser, but no overflow from Mastiff. At that point I'd rather be down in the Cage, but figured it would be a few hours until the next event there, so I'd have plenty of time to see Grand and then get down that way. Instead, there was a Turban Delay Interval.

And at that point, for the next three hours, Grand showed no signs of trying to erupt. After two hours, we got an eruption of West Triplet, but when it ended and Grand didn't erupt at the next opportunity, I decided that I'd rather be in the Cage and left.

2026-Sep-06 : 11:30:12

 11:30:13			d=02m45s	
 11:48:34	Int: 18m21s	d=03m08s	
 12:08:37	Int: 20m03s	d=03m07s	
 12:28:46	Int: 20m09s	d=03m29s	
 12:46:52	Int: 18m06s	d=03m38s	
 13:18:51	Int: 31m59s	d=04m34s D0	
 13:36:28	Int: 17m37s	d=03m31s D1	
 13:54:41	Int: 18m13s	d=03m31s D2	
 14:14:39	Int: 19m58s	d=03m37s D3	
 14:32:06	Int: 17m27s	d=03m45s D4	
 14:52:20	Int: 20m14s	d=03m27s D5	
 15:10:43	West Triplet
 15:11:41	Int: 19m21s	d=03m31s D6	
 15:28:04	Int: 16m23s	d=03m00s D7	
 15:44:26	Int: 16m22s	d=03m08s D8	
 16:02:45	Int: 18m19s	         D9	

Down at the Bijou Cage, there were some Bijou pauses, but no water was visible in Mastiff at any time. After four hours, in the dark we finally got a Standard Bathtub that lasted for 4m44s but didn't have any Southwest Vents spitting. At that point, everyone abandoned the Cage.

On the way back, I did stop briefly to watch an illuminated Castle eruption turning to steam.

(Grand finally erupted on D16 and a 12h20m interval. It also had two bursts.)

The trip down to the Bijou Cage at dawn resulted in a Standard Bathtub about an hour after I arrived, at 07:38.

There wasn't much of a wait for the morning One Burst Grand Eruption. West Triplet started during that eruption.

2026-Sep-05 : 10:42:15 T1Q

 10:41:48	Turban	-0m27s
 10:42:09	Boop	-0m06s
 10:42:15	B1	--- d=11m08s
 10:46:12	Vent	3m57s
 10:53:23	P1	11m08s
 10:54:16	V&T Quit	12m01s

				     	ΣD=11m08s
	* * * * *
 09:58:26			d=04m07s	
 10:18:09	Int: 19m43s	d=04m09s	
 10:47:37	West Triplet
		     Turban: 23m39s

Back in the Bijou Cage there wasn't much to see. A bunch of large Mastiff surges, but at best a minor slowdown from Bijou itself.

Did get the Beehive Indicator call, and got over in plenty of time. Unfortunately, it was windy and the wind kept shifting. When it started coming toward me, I ran through the rainstorm to the other side, toward Plume, and was out of the rain the rest of the eruption. A lot of people got soaked.

The less said about the next Grand wait the better. I arrived to see West Triplet in eruption and not only did Rift start a one hour eruption shortly after, but Grand had a Turban Delay Interval.

For the next five hours, we had a series of Turban eruptions with short durations (at one point, less than three minutes), and varying but short intervals. Finally, Percolator recovered from the Rift activity and began sputtering away, and a Turban eruption interval the few of us who waited it all out got a brightly lit One Burst Grand Eruption.

2026-Sep-05 : 21:58:11 D16/T1Q

 21:58:08	Turban	-0m03s
 21:58:11	B1	--- d=11m08s
 22:09:19	P1	11m08s
 22:10:27	V&T Quit	12m16s

				     	ΣD=11m08s
	* * * * *
 16:42:41ie	West Triplet
 16:57:52ns	Rift
 17:09:04			d=04m54s D0	
 17:27:29	Int: 18m25s	d=04m14s D1	
 17:47:20	Int: 19m51s	d=03m57s D2	
 18:07:17	Int: 19m57s	d=03m41s D3	
 18:26:50	Int: 19m33s	d=03m30s D4	
 18:44:13	Int: 17m23s	d=03m19s D5	
 19:02:43	Int: 18m30s	d=03m06s D6	
 19:20:09	Int: 17m26s	d=03m29s D7	
 19:40:28	Int: 20m19s	d=03m43s D8	
 19:58:21	Int: 17m53s	d=03m28s D9	
 20:15:36	Int: 17m15s	d=03m00s D10	
 20:31:55	Int: 16m19s	d=02m42s D11	
 20:48:52	Int: 16m57s	d=03m22s D12	
 21:06:45	Int: 17m53s	d=03m25s D13	
 21:25:09	Int: 18m24s	d=02m57s D14	
 21:41:52	Int: 16m43s	d=03m16s D15	
		     Turban: 16m19s

The plan was to get up early and head out to the Bijou Cage. Except when I got up, I saw that there was no report for Grand, but reports for other nearby geysers. So with a ten hour interval, it meant I headed to Grand first.

I arrived to West Triplet in eruption, so I figured that I wouldn't have to wait long. I did have to wait a full Turban eruption interval before the One Burst Grand eruption. West Triplet continued after Grand had finished, and Rift erupted shortly thereafter.

2026-Sep-04 : 06:49:33 T1C

 06:49:09	Turban	-0m24s
 06:49:21	Vent Ovfl	-0m12s
 06:49:33	B1	--- d=10m06s
 06:51:48	Vent	2m15s
 06:59:39	P1	10m06s
Vent & Turban continue

				     	ΣD=10m06s
	* * * * *
 06:27:00ns	West Triplet
 06:34:03			d=02m53s	
		     Turban: 15m06s

Finally made it to the Cage, and noticed there were considerable puddles on the platform and around the Southwest Vents. I saw some Bijou slowdowns and Mastiff surges, but it wasn't until I'd been there 1-1/2 hours that Bijou paused and water appeared in Mastiff. The pause lasted 3m20s, with the minimal Southwest Vents splashes, and was followed by Catfish and Bijou roaring.

Returned later to the Cage, and while there were some huge Mastiff surges, the only item of note was a short Bijou pause where Mastiff showed water, then rose about 10cm for about 20 seconds after Bijou came back on.

Back at Grand, arrived in time to see the Turban Delay interval. Turban started slowly, but over the next two minutes, it got stronger, and Grand did not show signs of dropping. It finally booped a couple of times and the One Burst Grand Eruption started. It took Vent over two minutes to finally start.

2026-Sep-04 : 13:47:09 D0/T1C

 13:45:16	Turban	-1m53s
 13:47:08	Boop	-0m01s
 13:47:09	B1	--- d=10m23s
 13:49:37	Vent	2m28s
 13:57:32	P1	10m23s
Vent & Turban continue

				     	ΣD=10m23s
	* * * * *
 13:12:31			d=03m31s	
 13:53:06	West Triplet d=02m57s
 14:03:07	West Triplet
		     Turban: 32m45s

A few minutes later, West Triplet started to erupt, but only continued for a couple of minutes. After Grand quit, West Triplet restarted, and continued on with what appeared to be a normal eruption.

I had just got to Castle to untie my bike when it started to erupt. This was the first observed eruption since early yesterday, and probably two major eruption intervals. About four minutes in Castle quit for a couple of minutes, then restarted and continued on with another major eruption.

Another wait in the Bijou Cage resulted in another Mastiff bathtub after a two hour wait. Bijou was off for 3-1/2 minutes, with the water in Mastiff only getting to about 20cm below overflow.

The Grand wait began well after sunset. Arrived in time to see a long Turban eruption, then the Turban Delay Interval. We heard Grand boil up and boop before an explosive start. The first burst was just over nine minutes, so a second burst was likely. This time, that second lasted well over two minutes, and had a false ending, then about ten seconds of more Big Sawmill splashing before the eruption was finally over.

2026-Sep-04 : 20:34:03 D0/G2*Q

 20:34:03	B1	--- d=09m10s
 20:43:13	P1	9m10s d=37s
 20:43:50	B2	9m47s d=02m12s
 20:45:54	FP	11m51s
 20:46:02	P2	11m59s
 20:46:43	V&T Quit	12m40s

				     ΣB=11m22s	ΣD=11m59s
	* * * * *
 20:07:37			d=04m17s	
		      Grand: 26m26s

This was the first two burst eruption of Grand since the one we saw a week ago. (All of the webcam reports were for one burst.) It raised my burst average to 1.17.

Went out to the Bijou Cage in the early morning. It was gray, damp and windy, and I was underdressed for the occasion. About an hour after arriving, I did see a short 2-3/4 minute Bijou pause where water was visible in Mastiff for a short time. The Southwest vents spit once or twice, and the usual post-bathtub activity (Bijou roaring, Catfish and B-C Vent activity).

After a re-configure in the cabin, I headed out to Grand. A three hour wait resulted in the One Burst Grand eruption occuring fifteen minutes after West Triplet started.

2026-Sep-03 : 12:09:53 T1C

 12:09:16	Vent Ovfl	-0m13s
 12:09:27	Turban	-0m02s
 12:09:29	B1	--- d=09m51s
 12:12:46	Vent	3m17s
 12:19:20	P1	9m51s
Vent & Turban continue

				     	ΣD=09m51s
	* * * * *
 09:22:38			
 09:40:42	Int: 18m04s	d=03m27s	
 10:04:44	Int: 24m02s	d=04m47s	
 10:22:32	Int: 17m48s	
 10:41:25	Int: 18m53s	
 10:59:54	Int: 18m29s	d=03m12s	
 11:15:57	Int: 16m03s	d=03m00s	
 11:34:09	Int: 18m12s	d=03m23s	
 11:52:23	Int: 18m14s	d=03m19s	
 11:53:10	West Triplet
		     Turban: 17m04s

After lunch, it was back to the Bijou Cage. It turned out that the Bijou pause observed earlier was the last one for the rest of the day. I spent another four hours in the Cage, and did see a number of good sized Mastiff surges, but they never lasted long, and Bijou showed no reaction to any of them. Some people stayed another three hours, well into the dark, and at the twelve hour mark, no Bijou pause.

I had left the Cage for Grand. There were a series of shorter Turban eruption intervals, and within a few minutes of West Triplet starting, once again we got a One Burst Grand eruption.

2026-Sep-03 : 19:42:12 G1C

 19:42:12	B1	--- d=10m03s
 19:42:13	Vent Ovfl	0m01s
 19:42:22	Turban	0m10s
 19:45:21	Vent	3m09s
 19:52:15	P1	10m03s
Vent & Turban continue

				     	ΣD=10m03s
	* * * * *
 18:45:30			d=03m30s	
 19:01:57	Int: 16m27s	d=03m40s	
 19:20:30	Int: 18m33s	d=04m16s	
 19:39:44	West Triplet
		      Grand: 21m42s

The wait for the morning Grand eruption was mostly uneventful. There was a short West Triplet eruption followed by a full length eruption about an hour later. Grand had its One Burst Eruption immediatly after that second West Triplet eruption ended.

2026-Sep-02 : 10:19:23 G1C

 10:19:22	Boop	-0m01s
 10:19:23	B1	--- d=10m14s
 10:20:20	Turban	0m57s
 10:22:10	Vent	2m47s
 10:29:37	P1	10m14s
 10:30:09	Drain	10m46s
Vent & Turban continue

				     	ΣD=10m14s
	* * * * *
 08:15:48			d=03m45s	
 08:38:27	Int: 22m39s	d=04m36s	
 08:40:43	West Triplet
 08:59:03	Int: 20m36s	d=04m08s	
 09:17:56	Int: 18m53s	d=03m53s	
 09:36:16	Int: 18m20s	d=03m49s	
 09:42:25	West Triplet
 09:54:42	Int: 18m26s	d=03m54s	
		      Grand: 24m41s

From there it was time to visit the Bijou Cage. About twenty minutes after I arrived, we got a large Mastiff surge, with a height of two or three meters. Bijou shut down for about three minutes, with water in Mastiff rising to within 20cm of the rim. There was only some weak sputtering from the Southwest Vents, but Feather did show water briefly.

About 20 minutes later I noticed water in Emerald's vent. That lasted only a few seconds, and wasn't repeated, but was the first time this trip I saw or heard of water there. Back in June I saw Emerald periodically overflow for about one minute in eight.

About an hour after the bathtub Mastiff had another surge, and a second an hour after that. Otherwise nothing much happened. (The next Bijou pause and Mastiff bathtub was in the early evening, about six hours after this earlier pause and bathtub.)

It was a windy day, so I was dressed for cold as I headed out in the early evening. There was a Turban Delay Interval lasting almost 31 minutes. After that, at some point, I noticed that Percolater was no longer erupting. The quiet continued until the fifth Turban Interval after the Delay, when we got a nice, early fill and a One Burst Grand Eruption. During that eruption, West Triplet finally erupted.

2026-Sep-02 : 18:58:00 D5/G1Q

 18:58:00	B1	--- d=10m38s
 18:58:04	Vent Ovfl	0m04s
 19:08:38	P1	10m38s
 19:09:47	V&T Quit	11m47s

				     	ΣD=10m38s
	* * * * *
 16:24:26			
 16:39:41	Int: 15m15s	d=03m50s	
 16:59:36	Int: 19m55s	d=03m48s	
 17:30:33	Int: 30m57s	d=04m07s D0	
 17:47:03	Int: 16m30s	d=03m44s D1	
 18:05:31	Int: 18m28s	d=03m17s D2	
 18:23:52	Int: 18m21s	d=03m48s D3	
 18:40:40	Int: 16m48s	d=03m37s D4	
 19:04:03	West Triplet
		      Grand: 17m20s

Walking through the Sawmill Group after the Grand eruption, I noticed that Oval Spring was pulsating and rising rapidly. Sawmill was erupting, but Spasmodic was below overflow. I got some video of Oval full with pulsations and waves over the vent, but no bursting. After about a minute, the pool calmed down and then began to drop.

The wait for the morning Grand wasn't too horrible. The rain had already started as I arrived in time for the Turban eruption prior to the Delay Eruption interval. The rain never got too strong during the next hour.

The rain had mostly ended when the One Burst Grand eruption started explosively, with a wide jet to at least ten meters. It was clear enough that I could see the details of the rest of the start of the eruption. I was able to get back to the cabin without encountering anything more than a slight shower.

2026-Sep-01 : 09:13:13 D3/G1Q

 09:13:13	B1	--- d=10m56s
 09:13:46	Vent Ovfl	0m33s
 09:13:59	Turban	0m46s
 09:16:55	Vent	3m42s
 09:24:09	P1	10m56s
 09:25:09	V&T Quit	11m56s

				     	ΣD=10m56s
	* * * * *
 07:39:59			d=03m30s	
 08:13:04	Int: 33m05s	d=05m04s D0	
 08:30:47	Int: 17m43s	d=04m07s D1	
 08:49:25	Int: 18m38s	d=03m50s D2	
		      Grand: 23m48s

With the rain continuing, it was a good time to be indoors. Finally, it was time to head back out to Grand. About twenty minutes after arrival, West Triplet started to erupt. It ended and Grand had shown no sign of any attempt at erupting, so it was wait for West Triplet to recover.

About an hour later Grand filled slowly and nicely, and we had a long One Burst Grand Eruption. Unfortunately, the overcast kept the eruption from having rainbows.

2026-Sep-01 : 17:21:28 G1Q

 17:21:23	Vent Ovfl	-0m05s
 17:21:26	Boop	-0m02s
 17:21:28	B1	--- d=09m56s
 17:21:32	Turban	0m04s
 17:24:38	Vent	3m10s
 17:31:24	P1	9m56s
 17:32:46	V&T Quit	11m18s

				     	ΣD=09m56s
	* * * * *
 15:24:56			
 15:41:34	Int: 16m38s	d=04m06s	
 15:53:57	West Triplet		d=32m46s
 16:05:45	Int: 24m11s	d=03m39s	
 16:21:57	Int: 16m12s	d=03m38s	
 16:41:39	Int: 19m42s	d=03m57s	
 16:59:49	Int: 18m10s	d=03m30s	
		      Grand: 21m39s

Afterward, I headed to the Bijou Cage for an hour, just to see how things are progressing. If I did not know of the eruption, and had last visited on Saturday, I'd think that not much had changed. During the hour Bijou never stopped, and was on strong. Mastiff was having strong depth charging from the front vent, and I saw two good Mastiff back vent surges. The second one lasted about 20 seconds, and was almost three meters high at one point. The Southwest Vents were making noise, too.

In the morning, did not head out until it was time for Grand. Glad I didn't try for the nighttime eruption, as the interval was about nine hours.

Walked up to the Grand Group with West Triplet full of water and starting to drain. Shortly after was a Turban eruption that was much shorter than typical.

Grand tried to have a Delay on the next Turban eruption interval, and failed. Instead we got 75 seconds of boops, including one that may have been five meters high.

After that, the One Burst Grand was pretty normal, although there was a short false pause at about the time a real pause would have been nice.

2026-Aug-31 : 11:03:07 D0/G1Q

 11:01:52	Boop	-1m15s
 11:03:07	B1	--- d=10m11s
 11:04:21	Turban	1m14s
 11:06:19	Vent	3m12s
 11:11:55	FP	8m48s
 11:13:18	P1	10m11s
 11:15:01	V&T Quit	11m54s
Vent & Turban continue

				     	ΣD=10m11s
	* * * * *
 10:31:53ie	West Triplet
 10:35:39			d=03m11s	
		      Grand: 27m28s

Sawmill was erupting, but Uncertain was pooling on occasion, so stuck around for that. Also got a Castle major eruption while waiting for Uncertain, which seemed to have a shorter duration than previous occasions.

Went on down to the Bijou Cage to see what was happening. Bijou was on strong, but not as high or powerful as it was before the eruption. Catfish was having occasional splashes also. Mastiff was having small surges from the back vent, while there was no depth charging from the front. The Southwest Vents were steaming gently.

A half hour at Fan & Mortar was a place to kill time before going over to see an eruption of Daisy.

West Triplet was erupting as the time of the evening Grand eruption approached. Forty-five minutes later, West Triplet ended just as Rift started to erupt. Except this Rift eruption was weak, and lasted less than 20 minutes. I watched the last minute, and the eruption activity by then consisted of a single vent sputtering to about 25cm, with no overflow.

A half hour later we got the One Burst Grand eruption. The sun had disappeared behind a layer of clouds, and there was only a hint of rainbow in the spray from Vent.

2026-Aug-31 : 18:38:34 G1Q

 18:38:34	B1	--- d=11m00s
 18:39:10	Vent Ovfl	0m36s
 18:39:27	Turban	0m53s
 18:42:23	Vent	3m49s
 18:49:34	P1	11m00s
 18:50:32	V&T Quit	11m58s

				     	ΣD=11m00s
	* * * * *
 17:24:04			d=05m01s	
 17:09:09ie	West Triplet		d>=39m31s
 17:41:25	Int: 17m21s	d=03m38s	
 17:48:25	Rift 			d=19m20s
 18:01:43	Int: 20m18s	d=03m28s	
 18:18:28	Int: 16m45s	d=03m30s	
		      Grand: 20m06s

Also, why is it necessary to add the redundant comment "saw it" to a geyser eruption entry?

Woke up at about 05:10 by the need to visit the indoor plumbing. Which with our cabin, means a short walk to a different building. It was dark, and it had rained, but the sky seemed mostly clear and the waning moon lit the area up. I got back and checked GeyserTimes for the Grand eruption time, it any. Found it, then noticed the entry above it… The webcam folks had an entry for Giant, almost an hour earlier.

Quickly got myself ready for a nighttime excursion and got on my bike. Arrived at Grotto at 05:45, and could see as I passed by that the Giant platform was steamy with Bijou off. Got over to the Bijou Cage, where Giant was huffing away down deep, and most of the log signs had been moved. There was a slight low tide smell, especially toward the back where grass got flooded. Thanks to the rain, it wasn't possible to tell the extent of any wash zones. Took some video with the powerful flashlight.

Hung around the area waiting for it to get light in order to take some video, and to meet others who were headed down basin. Around 07:00, a coyote started barking and howling nearby. I spotted it on the large rock just to the west of Oblong. This behavior continued on for at least a quarter hour, then it move off, probably disturbed by a person walking past Oblong. It continued to make noise, then a second coyote off to the south joined in, and that one headed toward it.

By 07:30, Grotto was still erupting, and the sky was getting dark and wet.

Spent much of the next hour waiting for the rain showers to lighten up while watching some activity from Spa and Grotto. Then it cleared enough that I was able to make a run for the cabin, and didn't get too wet.

Cold and damp and hungry, and by then it was time for a breakfast at the Lower Store. From there it was out to Grand with the last of the showers. Shortly after, Uncertain had an eruption. During the less than hour long wait, The sky cleared, but it also got a bit windier than it had been during the previous week. It was easy to see the One Burst Grand eruption, which lasted less than nine minutes. Well after that eruption West Triplet finally started.

2026-Aug-30 : 10:54:57 T1C

 10:54:11	Turban	-0m46s
 10:54:57	B1	--- d=08m54s
 10:58:36	Vent	3m39s
 11:03:51	P1	8m54s
Vent & Turban continue

				     	ΣD=08m54s
	* * * * *
 09:56:01			
 10:12:48	Int: 16m47s	d=03m05s	
 10:30:53	Int: 18m05s	d=03m11s	
		     Turban: 23m18s

By the time to go out to Grand again, it was clear, cool, and windy. I dressed warmly, even though the sun was out, as it was getting cloudy in the west, and the wind may not die down after sunset.

Got out in time to see both a Penta steam phase eruption, and the evidence that West Triplet had just ended an eruption. The latter meant there was going to be a bit of a wait for Grand.

As expected, that wait was just under two hours, with no pattern to the intervals between Turban eruptions. When it was finally time for Grand's One Burst Eruption, the pool did fill a bit early, and Vent overflowed for almost half a minute before Grand started.

The wind even died down a bit, which also allowed the tall jets at the start to reach full height. Then there was a gap in the clouds, so the last half of the eruption was nicely illuminated, with Vent contributing a nice rainbow.

2026-Aug-30 : 19:17:09 T1Q

 19:16:43	Vent Ovfl	-0m26s
 19:16:57	Turban	-0m12s
 19:17:06	Boop	-0m03s
 19:17:09	B1	--- d=11m06s
 19:20:05	Vent	2m56s
 19:28:15	P1	11m06s
 19:28:55	V&T Quit	11m46s

				     	ΣD=11m06s
	* * * * *
 17:28:21			d=02m45s	
 17:45:36	Int: 17m15s	d=03m27s	
 18:03:45	Int: 18m09s	d=02m59s	
 18:22:41	Int: 18m56s	d=02m47s	
 18:41:04	Int: 18m23s	d=03m55s	
 19:00:04	Int: 19m00s	d=03m19s	
 19:31:59	West Triplet
		     Turban: 16m53s

Based on past experience, the window for the next Giant eruption, if it is starting a new series, is from five to 21 days. That means we have a few days to do other things before starting to spend too much time in the Bijou Cage. From what we can tell from the leadup to this one eruption, the cessation of Bijou pauses and Mastiff bathtub events is a good sign. This tracks with past experience. Years ago, for example, having a series of regular Hot Period intervals that suddenly got much longer was a sign of possible impending eruption of Giant.

Suzanne stayed out in the Cage until midnight last night, because of the way the platform was behaving. Another observer saw the same minimal pause behavior from Bijou as short as two hours before the eruption. There were also changes in Grotto's behavior in the day or two before Giant erupted, with extremely short durations and intervals.

In this case, the key will probably be the observation of overflow from Mastiff, or erupting activity from the platform from a feature other than the Southwest Vents. Something that breaks up the series of events that all look similar.

After yesterday evening, I had no desire to go out for the cloudly, wet, moonless eruption of Grand during the night. Instead slept in a bit and then went out to the Bijou Cage to see what might be going on.

It was still gray and overcast, but the rains had quit and weren't supposed to be around for a few hours. Down in the Cage we were getting events every hour or so. What I saw were the minimum, with just Bijou pausing and water just visible in Mastiff, but later there were some with Southwest Vents activity and water visible in Feather. But what I did see were Bijou pauses that lasted well over four minutes, with the water in Mastiff only becoming visible midway through the pause.

After several hours, the weather got nicer, with some actual breaks in the clouds and sun warming things up. Transfered my attentions down to Grand, where once again it was over two hours of Turban intervals that slowly got shorter, down to about 16 minutes.

Then West Triplet started, and the One Burst Grand eruption started on the first opportunity ten minutes later. This eruption was notable in that there was a relatively long False Pause, a little over eight minutes into the eruption, that lasted about three seconds, long enough to note the end of the time. It felt like the pool was quiet, but a review of the video shows several boop-like boils during that short period.

2026-Aug-29 : 13:05:39 T1C

 13:05:17	Vent Ovfl	-0m22s
 13:05:20	Turban	-0m19s
 13:05:30	Boop	-0m09s
 13:05:39	B1	--- d=09m44s
 13:08:37	Vent	2m58s
 13:13:53	FP	8m14s
 13:15:23	P1	9m44s
Vent & Turban continue

				     	ΣD=09m44s
	* * * * *
 10:43:54			d=03m38s	
 11:02:35	Int: 18m41s	d=03m18s	
 11:21:06	Int: 18m31s	d=03m24s	
 11:39:43	Int: 18m37s	d=03m46s	
 11:58:14	Int: 18m31s	d=03m36s	
 12:14:30	Int: 16m16s	d=02m51s	
 12:31:22	Int: 16m52s	d=03m06s	
 12:47:23	Int: 16m01s	d=03m19s	
 12:55:48	West Triplet
		     Turban: 17m57s

Afterwards, the pouring rain waited until I was inside the cabin.

Waited several hours for the rain showers to stop, then headed back out to the Bijou Cage. Oblong started to erupt just as I rode past. Over at the cage, nothing much happened while I was there, then it was time to head back to Grand.

Walking through the Sawmill Group, I noticed that Churn was almost at overflow. Slurp was liquid with the usual steamy noise. Belgian Pool was high, with the side lobe full and a bit murky. In the past it seems that murkiness happens after heavy rains.

It was then I realized that I was an hour earlier than I needed to be. Instead of leaving, I just waited things out. As it was, the next Turban eruption became a Turban Delay Interval. After four more Turban eruptions, West Triplet finally started.

The One Burst Eruption took place on the second Turban eruption after West Triplet had started. As I had expected earlier, this eruption took place in that gap between sunset and moonrise, so it was pretty dark.

2026-Aug-29 : 20:59:47 D6/T1C

 20:59:45	Turban	-0m02s
 20:59:47	B1	--- d=09m50s
 21:09:37	P1	9m50s
Vent & Turban continue

				     	ΣD=09m50s
	* * * * *
 18:38:54			d=03m52s	
 19:12:41	Int: 33m47s	d=05m27s D0	
 19:30:30	Int: 17m49s	d=03m55s D1	
 19:49:30	Int: 19m00s	d=03m46s D2	
 20:08:28	Int: 18m58s	d=04m12s D3	
 20:26:26	Int: 17m58s	d=03m28s D4	
 20:31:59	West Triplet
 20:42:29	Int: 16m03s	d=03m15s D5	
		     Turban: 17m16s

Afterwards I went back to the Bijou Cage for a while, as there hadn't been any Bijou pauses or Mastiff bathtubs for several hours. By then the moon was well above the ridge, and the clouds had cleared away. Two hours later I left with no change in the activity.