That moment is generally regarded in the Northern Hemisphere as the start of the winter season, a time characterized by cold and darkness. But the daily weather depends on other factors as well, as Tuesday demonstrated. The high temperature was 57 degrees at Reagan National Airport, 12 degrees above normal. At Dulles International Airport, the high was 56 . Wednesday, the last full day before the solstice, is expected to be even warmer than Tuesday in the Washington area. The National Weather Service predicted a high temperature in Washington of about 60 degrees, which is in no way characteristic of winter. In addition, the Weather Service said there was “a chance of thunderstorms in the afternoon.” Thunderstorms are common in summer. They can occur in winter, but they are not ordinary events. Thursday, the day on which the sun touches Capricorn and immediately starts back to the north, was also expected to be warmer than the typical winter day.The Weather Service called for Washington area highs in the upper 50s, Autumn in Washington appeared likely to end on a wet note. The likelihood of rain Wednesday was 100 percent, the weather service said. Showers may also mark the start of Washington’s winter, according to forecasts for Thursday.