I’ve weighed all the factors, many of which we can chat about in the comments section. I’ve come up with an educated guess for how the weather will behave during the Winter of 2014-2015 in southeastern New England. I think one of the major players this Winter will be the above normal early snowcover in Siberia, which tends to lead to more periods of negative Arctic Oscillation and North Atlantic Oscillation. I also think a fairly strong Pacific jet stream, which tends to try to flood the Lower 48 with milder air, will be a factor. A wildcard is the emergence, or lack thereof, of El Nino, which was expected last Winter, but did not show, and is expected still, but has been basically a no-show again. I believe eventually we may sneak into a very weak El Nino episode that may have a very short life span.

Putting all this together with the other indices that are important in determining weather patterns, I have come up with this outlook for the Winter.

Winter overall (December through March): Temperature slightly above normal. Precipitation below normal. Snowfall slightly below normal.

Breakdown by month…

December: Tendency for AO/NAO to be alternating between weakly negative and weakly positive, a bit of a see-saw pattern, stronger Polar jet stream, weaker Subtropical jet stream, and a lack of phasing. Expecting the mildest part of the month, relative to normal, to be the first 10 days, with a colder trend for mid month and a milder trend at month’s end. Temperature near to slightly above normal. Precipitation below normal. Snowfall below normal.

January: Strong split flow, dominant Polar jet stream with moderate to strongly negative AO/NAO, but a little weaker than average Subtropical jet stream due to the lack of emergence of El Nino. A milder trend that comes at the end of December continues to early January before a cold pattern takes over. NAO strongly negative enough to result in dry weather rather than stormy weather. Snow would come from fast-moving Polar jet stream short waves. Temperature below normal. Precipitation below normal. Snowfall below normal. This will be the month of the cold outbreaks.

February: AO/NAO starts out with a negative bias then trends more positive. Still a split flow pattern but Subtropical jet becomes more active and Polar jet weakens a little. Phasing of streams, which had been not happening too often, happens a few times and brings an increased risk of storminess, but at the same time less intrusion of Arctic air from Canada. Temperature above normal. Precipitation near to above normal. Snowfall above normal. This will be the month with the greatest risk of major snowfall, despite it being considerably “milder” than January.

March: The pattern of February may spill over into early March but then retrogression sends Winter out West as the East warms and dries ahead of seasonal normal. That means Winter departs quickly in New England. Temperature above normal. Precipitation below normal. Snowfall below normal.

So, how much snow will Boston have this Winter? The average is 44 inches. They have had above normal snowfall during the last 2 Winters. The last time they had 3 consecutive Winters with above normal snowfall? The Winters of 1975-1976, 1976-1977, and 1977-1978. I think this may be a season where some of the excitement comes from watching that number to see if we reach #3 again, but we ultimately fall just short, with 41.1 for Logan Airport, the majority of it coming in the month of February.

That’s my best guess!