Winter will be here before we know it, and speculations about what’s in store have already begun.
Many turn to natural cues, from observing the color of woolly bear caterpillars or judging how frantically squirrels are caching their winter food. Others turn to The Farmers’ Almanac and National Weather Service, which have released extended forecasts for the coming season, in their annual attempts to gauge what’s to be expected over the cold months.
UConn researchers across multiple disciplines weigh in on the various methodologies, scientific or otherwise, for forecasting this year’s winter for the Northeast.
Extended Forecasters Have Their Say
The National Weather Service three-month outlook indicates equal chances for precipitation being above normal, below normal, or average for the northeastern United States for the next 90 days. In other words, there is no indication of anything unseasonal or out of the ordinary. Temperature-wise, however, there are indications that there is a 40-50 percent chance for continued above-normal temperatures from now through January, says atmospheric scientist and assistant professor of civil and environmental engineering Marina Astitha.
But she’s wary of over-reliance on forecast for the coming months. “As a modeler, I would urge caution on how to interpret long-range forecasts,” she says, noting that the most accurate forecasts are those given in the three- to five-day range.
Though long-range forecasts may not be straightforward, they can offer an approximation of the weather patterns we will experience. The way the National Weather Service Climate Center formulates these long-range forecasts is by using numerical models, statistical tools, and observations from previous decades, says Astitha.
“They cannot tell you what the exact weather will be in several months’ time, but they can tell you about patterns and probabilities.”
In contrast to the National Weather Service’s outlook, the Farmer’s Almanac is calling for snowier than normal conditions this winter. Astitha points out that the Farmer’s Almanac forecast doesn’t reveal its methodology for making predictions. “The Earth is telling us what is happening if you look at the signs, so there might be some wisdom in the Farmer’s Almanac predictions,” she says. “With science we try to be more specific.”
Reading Nature’s Signs
The timing and progression of seasonal events such as migrations, leaf emergence, and leaf senescence or aging is known as phenology.
David Wagner, professor of ecology and evolutionary biology in the College of Liberal Arts and Sciences, says the reverse migrations of some insect species are sure signs of the changing season. Here in Connecticut, we are graced with two groups of insects that have impressive migrations – butterflies such as the Monarchs and dragonflies such as the strikingly large Green Darner. It may still be possible to catch a glimpse of these spectacular creatures as they prepare for their long journeys. The traffic picks up especially closer to the coastline, he says.
There are also less scientific, more anecdotal signals that many turn to, such as the woolly bear caterpillar, Pyrrharctia Isabella. The caterpillars are believed to be harbingers of winter weather, based on their coloration. However, Wagner has doubts about these fuzzy forecasters.
The caterpillars’ coloration includes both brownish-orange and black segments. Some people believe that greater proportions of black segments of “wool” on the caterpillars’ thoracic and abdominal segments signify more weeks of snowfall, while caterpillars with more orange segments foretell average temperatures with only dustings of snow.
Wagner says this is implausible. “I believe in climate models, I don’t believe the woolly bears,” he says. “Plants and animals can’t predict the future.”
Another often cited signal of weather to come is the degree of winter preparations made by squirrels. The belief is that the more frantic the squirrels, the more severe the winter will be – and this year the squirrels seem especially active.
Associate extension professor in the College of Agriculture, Health, and Natural Resources and chair of the UConn Forest Management Committee Tom Worthley says the reason squirrels may appear to be more active this year is because nut crops were abundant in the previous two years, and this may have contributed to an increase in the squirrel population. In addition, this season there are fewer acorns available, due to the devastation caused by the gypsy moth caterpillars earlier in the year. The squirrels are not necessarily expecting an especially bad winter – setting aside food is simply what they do at this time of year; but in years with fewer acorns like this year, there is heightened competition for the available resources.
A ripple effect we may see from this abundance of squirrels, if they survive the winter, is a continued abundance of ticks, says UConn associate professor of pathobiology and tick-borne disease expert Paulo Verardi, also of CAHNR, noting that the offspring produced by this year’s rodents will mean more hosts next year for the seemingly ever-growing tick population.
Though it may be true that plants and animals can’t predict the future, working to understand the intricacies and responses within ecosystems is important, and can help us anticipate similar situations in the future.
How Citizen Science Can Help Improve Forecasting
Astitha says citizen science is helping to make existing models more powerful. For example, homeowners and schools have been able to install weather stations and share their weather data with the National Oceanic and Atmospheric Administration and the National Weather Service.
Citizen scientists can also contribute data through the National Phenology Network, where observations of plants and animals can be recorded to create useful data for researchers, resource managers, and curious nature lovers.
Current observations and data are helping improve the models and technology used for making long-range weather forecasts, and the more data that are collected the better. “In the future, we will have more trust in the long-range predictions, as technology will continue to increase our capabilities and we will have more observation data and more tools,” Astitha says.
For now, the weather in the months ahead remains uncertain. In the meantime, for accurate local three- to five-day forecasts, check in with UConn’s Atmospheric and Air Quality Modeling Group’s weather forecast – and note and enjoy the seasonal changes taking place all around.
By Elaina Hancock | Story courtesy of UConn Today