Geyser Watch

~~Photo: An eruption of Old Faithful at Sunset~~

Afterall, aren’t the geysers predicted?

So many visitors to Yellowstone expect the prediction to actually be 100% accurate. They find themselves impatiently waiting for it to erupt. Don’t be one of those – that only adds stress to a vacation meant to be something to relax and enjoy.

The eruption predictions are actually just the middle of a forecasted window of likely opportunity to see an eruption. A true prediction would mean people could tell you when a particular thermal feature will erupt tomorrow or the next day. And, geysers – being geysers – keep us guessing more than anything. Old Faithful is the most famous, and most well known – and has the most documentation. But even with that, it’s not close to letting us know anything more than just a good guess of about 20 minutes in which it will likely erupt only for the next eruption.

Rangers calculate this window based on the time the last eruption started and how long the eruption lasted. That means they need to wait until the first observed eruption each morning to start the calculations. Right now, the average time between predictions is 92 minutes – so think of it as an hour and a half. But at times, they guess wrong. For some reason it either erupted early or late. Usually, though, the eruption will happen within the 20 minute window. If you know that window is 20 minutes, then to make sure you catch it, give it a full 30 with 15 minutes before and after the actual posted prediction time.

Where do you find the predictions?

Check in at the Visitor’s Education Center at Old Faithful – the geysers with forecasted windows (with the prediction in the middle of it) are listed on the board behind the desk. The geysers currently predicted are:

• Old Faithful: 20 minute window – erupts about every 92 minutes on average – eruption lasts about 4 minutes
• Castle: 2 hour window – erupts about every 12-13 hours (unless it minors, then all bets are off) – eruption lasts about 50 minutes including the steam phase
• Grand: 4 hour window – erupts about every 8 hours – eruption lasts for 7-9 minutes – this is the tallest predicted geyser in the world. If you have a choice between Grand or Old Faithful, choose Grand. It’s worth the wait.
• Daisy: 1.5 hour window – Erupts about ever 3 hours for 3-4 minutes
• Riverside: 1 hour window – erupts about every 6 1/4 hours for about 20 minutes
• Great Fountain: 4 hour window – erupts twice a day on average (so at least one time during daylight hours). You’ll need to get in your car and drive to the Lower Geyser Basin for this one.

And for Old faithful you can also  just check the number of people waiting on the benches around Old Faithful. The crowds increase as the time for the eruption nears.

New ways to learn what’s happening with the geysers

With new technology, and cell reception at the major hubs in the Park, you can check online at a couple of developing sites that give wonderful nearly live information. Plus, you can share your observations as well!

Geyser Times and Geysers Net

And, here at Geyser Watch you can check the calendar for a compilation of observations found in a variety of places.