Precipitation maps that help predict mushroom hunting success

Wild Mushrooms Love a Good Rain

As Modern Foragers, we spend a lot of time using various precipitation maps from around the web. In fact, we’ve even blogged about these online rain research resources.

While we love these maps, they are often difficult to use and we end up bouncing back and forth between maps to find what we want. With that in mind, we decided to build our own precipitation explorer that is more focused on mushroom hunting (in the burns and generally). Our burn map purchasers will see rain data overlaid on our burn perimeters in their version of the map!

Here is what is important

1. Historical precipitation. We may want to see the last week, or the last 2 weeks. In fact, in the West when we morel hunt we have learned we want to see at least six weeks of rain data. It seems this is how long truly abundant morels take to form and fruit in the burns.
2. BIG picture maps, because often we are planning to travel and trying to determine the best place to hunt. Is Western or Eastern Oregon better? Washington, Montana or Idaho?  Or, how does New Mexico look this year?
3. Detailed maps. How much rain did one spot get? Not just yesterday, but in the last 6 six weeks.

Well, we did it!  Here is what we made, a map that:

1. Shows precipitation data in all of North America.
2. Scores mushroom probability in North America based on regular rainfall over 6 weeks. Initially, our algorithm is easy – 1 point every week for the last six weeks if 1″+ of rain happened. 6 is a perfect score. 
3. Allows us to easily choose a past date range within the last 6 weeks and see precipitation. We added an algorithm to weekly views as well, scoring each week on 0″-3″ inches of rain. Use the layer picker in the top right corner to select a specific week.
4. Shows precipitation data for a specific location. Just click on the map, zoom in, and the map will show you the last 6 weeks of rain for that spot.

It’s pretty sweet! Please comment below if you agree – or, if you think our algorithm tweaked to be more relevant. We will test and modify if it makes sense!

Take a look at the static screen capture of the map below. As of the date of this posting (assuming we were already in season), we would want to be hunting morels in northern Washington, the northern half of Idaho, and also the area between Bozeman and Idaho falls. See static map capture below. An example of the interactive precipitation explorer it at the bottom of the post.

Modern Forager Precipitation Explorer

Here it is! Read the instructions at left and play around with the map. Tip – first hover over “Layers” at top right and take a look at your options. You can see rainfall ratings for weeks 1, 2, 3, 4, 5, or 6, OR, you can click on “Mushroom Probability” to see ratings for cumulative rain in the last 6 weeks. Use the slider to change opacity so you can see your location pin if you wish.

NOTE: selecting all the weeks at the same time is not useful, it just layers the data for each week on top of each other. This is a limitation of our software.

So toggle each week on/off, or toggle on/off mushroom probability to see the long range view. There’s a lot of data here – give it a minute to load. If you are on a slow internet connection it could take a bit to render the data.

We’re super excited about this new tool! It’s fantastic for burn morel hunters but can also be used in your own areas around the country to give you a quick picture of rainfall in the last 6 weeks. Let us know what you think!

Interested in 2023 burn morel hunting maps? They are ready, get in and get yours today!