To Moth or Not to Moth?

We had another Mothing Zone event canceled last night. I thought you might be curious how we make that decision.

Let me first start by saying this is not a decision we take lightly. While we can collect moth data pretty much anytime since we live on site, we absolutely value the opportunity to teach other folks about these amazing insects. Most of our human Mothing Zone attendees have never done this sort of thing before, and we want to make sure it is memorable and educational. So having to cancel is a bummer for us as well.

The primary reason we cancel is concerns with weather. Amongst the equipment we use for the program is mercury vapor technology. The bulbs and ballasts get quite hot during the mothing evening. There is real concern that cold rain hitting those hot surfaces could cause considerable damage to the equipment, including but not limited to bulbs shattering. With recent trends in light pollution laws, mercury vapor equipment has become much more difficult to find and acquire. Therefore, we need to be rather protective of this equipment.

We start watching the Saturday night weather report actually on Friday. If the forecast is looking concerning we will make advanced announcements that the Saturday night program may need to be canceled. We have folks who come from long distances for this event. In fact, we had three people who were planning to come from the Cleveland area (three-hour drive one-way) for last night’s event. I want these folks to have plenty of time to reconsider the trip.

For the benefit of those who may be coming from a long distance, we try to make the decision to cancel by 4-5pm Saturday afternoon. Once we make this decision, the decision is made. We do not revisit the decision. We just hope we made the right one and deal with the consequences. Those consequences could be anything from the disappointment of cancelling the program when we didn’t need to, to having to rush around the property shutting down equipment in the dark when the 10% chance of rain suddenly turns into 100%.

Based on past performance of weather forecasters, if the chance of rain on the majority of the weather apps we consult (we frequently check five different apps) is 30% or greater we cancel. I realize a 30% chance of rain means there is a 70% chance it won’t rain. In our experience over the last few years, a 30% chance is nearly a guarantee of rain.

A luxury that the forecasters have which Butterfly Ridge does not, is that they can change the forecast. Yesterday, between 5:30AM and 8PM, the forecast for Saturday night changed significantly five times. At 5:30AM I was saying to myself, “Looks like we will be cancelling”. At 6:00PM I was saying to myself, “Looks like a beautiful night for mothing and I just canceled it!”

Add to the decision is that I have had a few classes in meteorology. I have at least some understanding of how weather works. Keeping with yesterday’s example, in late afternoon, the future radar was showing a definite line of storms setting up. The weather apps, all of them, seemed convinced that this line was going to dry up about 15 miles west of Butterfly Ridge. I didn’t buy it. The cancellation stood and I felt good about the call.

At 10PM, the chance of rain for Butterfly Ridge within the next hour stood at 99 percent. A brightly-colored line of storms was positioned about 20 miles west heading directly at us. And while I was asleep long before eleven, the puddles and downed branches that greeted me this morning assured me we had made the right call.

Of our eleven Mothing Zone events this year, on and off-site, all but three have been impacted by rain. Which is some kind of record for us! I know rain is important for healthy habitats, but maybe it could fall on Wednesday nights instead!