By Gabriella DeLuca, ’27

Staff Writer

Every winter, students across the country find themselves asking the same hopeful question: Will there be any snow days?

Over the last weekend of January, towns across Massachusetts were buried in nearly two feet of snow. Following this powerful winter storm, schools across New England were closed, some even for two days. This was the first real snow day our school has had in years and has many students wondering if this past snow day will not be the last.

It is not hard to notice the similarities between this recent winter storm and the infamous blizzard of 2015, which initially hit New England on the exact same date, January 26th, and brought over two feet of snow. This resemblance has some people wondering if this season will mirror the winter of 2015, which covered towns across Massachusetts in a record-breaking 100 inches of snow, and led to relentless school closures where even the students grew tired of the cancellations. Yet, others are speculating that this past snowstorm may have been this winter’s last hurrah before giving way to an early spring.

In order to make an accurate predication about the forecast for this year’s snowfall, it is important to consider the scientific factors that influence the winter weather of Massachusetts.

Oceanic Nino Index

The Oceanic Nino Index is a dataset used by meteorologists to measure the differences in normal sea surface temperatures in the east-central Pacific region. La Nina is a climatic pattern that describes the periodic cooling of surface-ocean temperatures in the equatorial region of the Pacific Ocean. It is considered to be the counterpart to El Nino, which is the pattern of unusually warm ocean temperatures along the tropical west coast of South America. La Nina brings warmer, drier conditions to parts of the southern US, and colder, snowier conditions to the New England area, while El Nino typically brings warmer and wetter weather conditions.

This winter, meteorologists predict weak La Nina conditions, which are expected to be mild in intensity and fade later in the season. For New England, this suggests colder-than-average temperatures and an increased chance of snow in December and January, followed by milder conditions in February and March.

Eastern Pacific Oscillation

Another important aspect to consider when determining the weather trends for this winter is the Eastern Pacific Oscillation, often referred to as the EPO. The EPO is a pattern of atmospheric flow across the Eastern Pacific region and can have a strong influence on how much cold air reaches North America. This season the EPO is in a negative phase, which means that a high-pressure atmospheric ridge is building near Alaska and blocking the typical west-to-east flow of mild Pacific air. For the northern US, this ends up resulting in colder than average temperatures. Since cold temperatures are a key ingredient for snowfall, this negative EPO could indicate higher-than-average snow totals for the northern region of the US. However, the negative EPO does not always guarantee frigid temperatures for Massachusetts, as warm Atlantic waters near the coast can moderate the cold temperatures created by the negative EPO. This could mean that precipitation could fall as rain instead of snow. Overall, the impact of the EPO on snowfall in Massachusetts is uncertain; however if the cards align, there is a chance for some more significant snowstorms in the future.

Pacific Decadal Oscillation

The Pacific Decadel Oscillation refers to a long-term ocean temperature fluctuation of the Pacific Ocean. The PDO varies from a “cool” or “negative” phase to a “warm” or “positive” phase every 20 to 30 years. This year we are experiencing a strongly negative or “cold” PDO. This means colder-than-normal conditions in the Pacific Northwest, but means warmer-than-normal temperatures across much of the country, including Massachusetts. In July 2025, the PDO reached the most negative value on record which was associated with record-breaking warm summer temperatures in New England. The last several winters had these same strongly negative PDO patterns, which likely played a part in the less snowy winters experienced in New England.

The Polar Vortex & The Jet Stream

The polar vortex is a wide low pressure area of swirling cold air located in the atmosphere of the polar regions. However, this year, the polar vortex is predicted to weaken. This means that this system filled with Arctic air can break off and flow south, bringing its cold air with it. When the polar vortex is strong and stable, it keeps the jet stream in its normal path. The jet steam is a band of strong wind located in the upper atmosphere that encircles the earth and plays a critical role in keeping colder air north and warmer air south. However, as the polar vortex weakens, the jet stream begins to wobble, causing cold shots of frigid air to travel into the mid-latitudes, including Southern New England. This favors a colder & snowier winter in New England.

Siberian Snow Theory

The Siberian Snow theory refers to the concept developed by climatologist Dr. Judah Cohen that the snowfall in Siberia can be used to determine the severity of winters in North America. Located in the northern Arctic region of Russia, Siberia experiences the Siberian High, a high-pressure atmospheric system that brings cool temperatures and snow beginning in early October. According to Dr. Cohen, an above-average snowfall in this region is likely to be followed by a colder and snowier winter season in New England. Last October, Siberia experienced a relatively average snow cover, which predicts average snow totals for the United States.

In summary, forecasts for this year’s winter season offer a mixed outlook:

• A weak La Nina is predicted to bring a snowy December and January, followed by a milder February and March.
• A negative Eastern Pacific Oscillation suggests the possibility of colder temperatures and snowstorms.
• A negative Pacific Decadel Oscillation points toward a milder winter overall.
• A weak polar vortex predicts a colder and snowier winter.
• Finally, the Siberian Snow theory forecasts an average winter.

Based on this information, while a definitive prediction is hard to make, there is a real possibility for more snow on the horizon! Whether it will amount to more snow days, though, is anybody’s guess.