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Extreme weather fluctuations to continue into March

A mild start to the work week will transition into increasing clouds Tuesday afternoon, with seasonable highs in the upper 30s to around 40 degrees. Days in which temperatures run close to average have been far and few between this February.

Frankly, there are very few periods in New England weather when the line ďthe weatherís been anything but typicalĒ doesnít apply. Even by this region's standards, the recent temperature changes have been extremely extreme. Researchers would need to do a statistical analysis of the most recent fluctuations to see just how out of the ordinary they are, but some research shows the temperature extremes, especially on the warmer side, are becoming more frequent. For example, the image below shows how summertime nighttime temperatures are on the rise.

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Snowfall this season
You might be a bit surprised to learn the roughly two feet of snow fallen so far this winter in Boston is only about 6 inches below average. Worcester has a greater deficit, with 15 inches less than the long-term snowfall average. While this small deficit in snowfall isnít statistically unusual, itís a monumental change from a year ago, when we had seen 75 inches more by this time.

You could point out that our records only go back to the second half of the 19th century, so there are plenty of unknowns. But for the current climate, these fluctuations are quite remarkable.

Wild temperature swings
Ten days ago, temperatures reached record cold levels we havenít seen in half a century. This was followed a few days later by readings in the 50s. This past weekend, temperatures were averaging 10 to 15 degrees outside the typical range. Over half of the days this month have seen temperatures over 10 degrees above or below average: in other words, more evidence of wild swings.

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These numbers are just for Boston, but much of New England has seen a similar pattern this winter. In 2013, a study published in the journal Advances in Atmospheric sciences looked at recent trends in winter temperature extremes in Eastern China and their relationship with the Arctic Oscillation, or AO, and El Nino/Southern Oscillation, or ENSO. The study found that, since the mid 1980s, parts of China were seeing more extremes during the winter, some of which may be connected to both oscillations.

Arctic and ocean connection
This year, both ENSO and the AO have been at the more extreme ends of the scale. There is likely a connection between what we have observed this winter and those atmospheric players.

This theme of fluctuation is going to continue this week with spring-like warmth again on Thursday along with a significant amount of rainfall. Unfortunately for skiers and winter sports enthusiasts and plow operators, our next storm will pull mild air northward and ensure a wet, not white, event.

More of the same
Although Thursdayís storm is a mild one, there could be enough rain to cause travel headaches both in the morning and again in the evening. Winds will be brisk from the south and temperatures could reach a warm 60 degrees. I wouldn't be surprised to see more power issues.

It appears the core of the arctic air won't bother us until perhaps the first week of March. The image loop below shows air masses of below and above average moving through the wind flow. Notice how quickly we alternate between warmth and cold. In other words, not prolonged winter chill in sight.

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