World and Nation

Standard Deviation Forecast: High

Standard Deviation Forecast: High

As you’re recovering from Monday morning’s low of 14°F (normal low: 30°F), take comfort in the fact that Wednesday’s high temperature is forecasted to approach 60°F (normal high: 43°F). Often the media quotes the climatological average highs and lows as part of their statistics, but an often overlooked piece of information is the standard deviation, especially in mid-latitude climates like Boston. You may have noticed that the variation in temperature during the winter season is quite high. For example, in January of this year, the lowest temperature for the month was 7°F, and just five days later, the high temperature was 67°F! Yet during the summer, the temperature stays within a narrower range. This difference between the season has to do with the temperature gradient that exists between the equator and the poles. During the winter, the gradient is the strongest in a tight band that weaves across the U.S. Depending on the north-south position of that band near Boston, we may see very cold weather (if it is south of us), or very warm weather (if it is north of us).

And if that weren’t enough, this week holds the potential for some memorable winter storms. The first round, which looks to be mainly rain, will impact us Wednesday. Another storm on the horizon for Friday or Saturday is still rather uncertain, but holds the possibility for significant snowfall.

Extended Forecast

Tonight: Cloudy with temperatures steadily increasing. Chance of rain showers late. Temperatures reaching 50°F (10°C) by early morning.

Tomorrow: Rain. High 57°F (14°C).

Tomorrow night: Rain, possibly freezing rain or snow late. Low 34°F (1°C).

Thursday: Partly cloudy. High 38°F (3°C). Low 26°F (-3°C).

Friday: Sleet and snow. High 35°F (2°C).