Yellowstone and jackson
 

Our trip to yellowstone and jackson hole is all planned for next week, unfortunately the 10 day forecast is showing a lot of rain. Does this usually mean full days of rain or brief showers. We do have trip insurance, should we cancel and go somewhere else, we would lose one night lodging in old faithful. All suggestions welcome,

Go and make the best of it. Pack your ponchos. You will see less people on the trails which is a good thing.
If it is rainy and cloudy, spend more time in Yellowstone and less in Grand Teton since the distant mountain pictures would be poor.

If anyone could predict weather with a 100% accuracy they would make a fortune. That is the last thing we worry about (cannot control it) other than making sure we have clothing for all conditions.

We sit on the front range of the mountain somewhat similar to Yellowstone. We get all kinds of rain. The most common in the summer is the afternoon thunderstorm that roll off the mountains as the plains heat up during the day. Those can be relatively short (30 mins) and sometimes come in waves. Other times it can rain all day. Just came through a period of about 36 hours where it rained or at least drizzled the entire time.

Just go and take a rain jacket and umbrella. Somehow there are more important things to worry about.

I looked on this site:

https://weather.com/weather/tenday/l/USMT0353:1:US

and put in other locations like Gardiner, Cody, and Yellowstone NP. They all showed a couple of rainy days, but if you look at the % it's mostly very low.

You can't control it, so don't panic, go, relax and enjoy. I hope the baby animals have started to appear, you can see them from your car.

I wouldn't cancel and actually don't think the forecast looks that bad. We were there about the same time last year and got a little bit of everything including rain, snow and sunshine. There should be plenty of "red dogs" (baby bison) and this is a good time of year to try to spot bears near the road as they feed on winter carcasses.