“Our science has come a long way, but there are still many moving parts in the atmosphere which creates quite the forecast challenge.”
Thus explained the New York City office of the National Weather Service, after last week’s storm did not come close to producing the blizzard conditions and 18-24″ of snow accumulation that the NWS had predicted for the city and parts of New Jersey and Pennsylvania. The prediction led to an unprecedented, preemptive travel ban in the area. New storms are sure to hit before winter winds down, but hashtags like #snowperbole and #snowfail still on the tips of people’s fingers, the skepticism surrounding forecasts is strong. Are there better options for predicting the weather than hitting refresh on Weather.gov?
While weather folklore of dubious accuracy abounds in all cultures, it turns out there is some evidence that rural subsistence farmers are adept at applying local and cultural knowledge to predict the weather. For example, the Tsimane’ people of the Bolivian Amazon use weather-related cultural knowledge to preferentially harvest their crops in the 1-3 days before rain storms. When asked how they know rain was on the way, the Tsimane’ people say they consider animal and insect behavior, halos of light around stars, cloud consistency and movement, and whether there’s been a recent death in the community. It’s not clear exactly how this information translates into weather patterns that we would recognize, but it’s not impossible that it might.
In 2002, a cross-disciplinary team was able to tie this kind of local knowledge to an established climatological phenomenon. The researchers were investigating a forecasting rule of thumb used in multiple villages in the Andes, wherein farmers assess the appearance of the Pleiades star cluster in June to predict future rainfall and determine when to plant. If farmers found the Pleiades to be bright and highly visible, they would plant their potatoes at the usual time in October, but “dim, small, scanty” Pleiades indicated that the rains would be later than usual.
The team checked historical weather data against the farmers’ accounts and noticed that years with dim Pleiades and late rains were also El Niño years. They then puzzled over exactly how the El Niño phenomenon was manifesting itself in the farmers’ observations, hypothesizing that the increased atmospheric water vapor and turbulence measured during El Niño summers could obscure the Pleiades during the time the farmers’ were looking for them.
Also, because El Niño leads to drier winds from the west, it could prevent moister air and showers from reaching the Andean highlands during the growing season of those years. While these rural farmers are certainly not formally trained in meteorology, it would be a huge mistake to say they’re not experts.
All of this is fascinating, and yet, based on cursory research, it would appear that those of us who tend toward the more urban, non-farming end of the spectrum are a bit out of luck when it comes to predicting the weather on our own. Which is understandable—these people’s livelihoods depend on understanding the weather in a way that ours don’t, regardless of how inconvenient it is to sleep in the airport for two nights after one’s flight is canceled. All we can do is cut the weather forecasters some slack, hope that their upcoming computer upgrades improve future predictions, and pray that somehow the groundhog doesn’t see his shadow.