A milder winter ahead?
TUPPER LAKE – It’s been a mild and rainy summer, but meteorologists say that might make for a milder winter.
On Tuesday, two meteorologists from the National Oceanic and Atmospheric Administration’s National Weather Service forecast office in Burlington, Vermont, Conor Lahiff and Brooke Taber, gave a presentation at The Wild Center called “Why Was Last Winter So Cold?” to talk about weather patterns in the Adirondacks.
The weather station tracks weather patterns and storms across the Adirondacks and Vermont.
Despite the 30-degree-below-zero nights that persisted into March, the average overall temperatures of the season didn’t make it one of the coldest on record. That doesn’t mean it wasn’t cold, though.
As a whole, North America’s March was 9 degrees colder than average, and two-thirds of the Great Lakes remained frozen until April. Alaska’s January was the third warmest on record, though, and most of Europe also experienced above-average temperatures.
Lahiff explained that temperature fluctuations in the North Country kept the average temperature from reaching record lows. There were 20-degree-below-zero nights that gave way to 30-degree days – a 50-degree difference.
On a much larger scale, extreme differences in atmospheric pressure affect how jet streams and weather move across the planet. Pressure refers to the force, or weight, of air molecules on the earth’s surface. Those differences affect things like temperature, wind, cloud formation and weather.
“There is always low pressure up at the pole, so somewhere else there has to be high pressure to equal it out,” Lahiff said. “The earth and the atmosphere are always trying to equal themselves. If you have low pressure somewhere, you have high pressure somewhere else.”
Lahiff explained that meteorologists look out for two types of atmospheric events, El Nino and La Nina, to get a glimpse into upcoming seasonal weather predictions.
This year, meteorologists are predicting an El Nino will influence winter, which could mean milder temperatures and more precipitation. But that’s still a long way off.
“Forecasting across our area is pretty tricky,” Lahiff said. “We have extreme elevation differences from about 200 feet at the lake level, all the way up to 5,000 feet in the Adirondacks. That sharp, quick rise plays a role in a lot of the weather we get across the North Country.”
In an El Nino year, the cold, low-pressure polar jet stream stays further north while a tropical jet stream fills the void by moving up from the south.
In a La Nina pattern, warm, moist air coming off the northern Pacific Ocean dips down into the southern portion of the U.S. and curves back up, leaving a large trough for cold northern air to fill.
“The winters of 2010-11 and 2011-12 were both moderate La Nina years, but they were vastly different,” Lahiff said. “2010-11 was cold and snowy, one of the highest record snows in the Burlington area. Then there was 2011 and ’12, another La Nina year, but it was warm; one of the warmest winters we’ve had on record, but there was no snow.”
Lahiff said the last two winters were more of a neutral phase, somewhere between La Nina and El Nino conditions. He said snowfall was average both years, but last year became markedly colder, especially in February and March.
“Last year wasn’t bad,” Taber said. “It was only the fifth coldest March on record, and the records go back from 1895 to 2014. January and February were actually pretty average. One of the coldest winters on record for Lake Placid is actually December of ’89. In that whole month, the average temperature for Lake Placid and Saranac (Lake) was only about 10 degrees. You have to remember, the average low in Saranac Lake in the middle of January is about zero.”
A member of the audience asked if climate change has had an effect on North Country weather. Taber said there is research that links declining sea ice to slower jet streams.
“Without the sea ice creating the temperature difference, the jet stream is weaker,” Taber said. “The sea ice acts as a real cold refrigerator, and then the contrast down to the south is the warm tropics. We may still have really strong storms, but they may persist for one, two, three days, and that may in turn result in more precipitation.”