D.C. cold spell could become one of the city's longest in 150 years

Washington, D.C., has fallen into single-digit and below-zero temperatures and could see a run of freezing days lasting into early February; the National Weather Service has issued cold-weather advisories and expects more this week.

Washington, D.C., and the surrounding region are in an extended cold spell with many morning lows in the single digits and some locations below zero. The outbreak deepened after a winter storm over the weekend and has left heavy snow and ice that are expected to persist. Local waterways are beginning to show ice, and forecasters say the pattern is tied to a persistent southward dip in the jet stream that is funneling Arctic air into the eastern United States. Officials anticipate the cold to continue into early February under current model guidance. Current details: - Temperatures have dropped into the single digits in many places; D.C. recorded a morning low of 13, while nearby sites fell lower (for example, Dulles at 4 and Manassas near minus-1). - Forecast blends call for several more days with daytime highs in the 20s or lower and multiple nights with subzero wind-chill readings. - The National Weather Service has issued cold-weather advisories for the area and said additional advisories are likely through the week due to overnight subzero wind chills. - Snow and ice from the recent storm are expected to remain firm for 7 to 10 days, and portions of the Potomac are already icing with unusual ice cover possible on parts of the Chesapeake Bay. Summary: The entrenched Arctic pattern has produced an unusually long stretch of freezing conditions that, if it continues, would rank among the longest such runs in D.C. since the late 19th century. Forecasters expect continued subfreezing highs, recurring cold advisories from the National Weather Service, and persistence of snow and ice into the coming week. Undetermined at this time whether the pattern will break before early February.