Major Pattern Change

There has been a major change in the weather pattern in the Nation’s Capital following a warmer and wetter than average start to 2017.  My colleagues and I on the WUSA9 weather team are tracking the coldest weather of the season to date in the Mid-Atlantic Region in conjunction with the prospect of the first measurable snowfall of the season tonight. 

This month is similar to the four previous Januarys which featured a major shift in the weather pattern from significantly warmer than average temperatures to much colder temperatures in 48 hours or less.  For example, Washingtonians enjoyed a balmy high temperature of 62 degrees on January 20, 2013 and just two days later the high temperature at National Airport was only 32 degrees.  That was the first of four consecutive days with high temperatures at or below freezing in the Nation’s Capital and remains the longest such streak of the last five years.

January 2014 was nearly four degrees colder than average in the Nation’s Capital and saw seven days with high temperatures that remained below freezing.  There were several dramatic temperature swings during that month, such as the 31-degree swing between the high of 54 degrees on January 27 and the frigid high of 23 degrees on January 28.  By comparison, January 28’s average high is 44 degrees in Washington, D.C. 

January 2015 saw less snow than average in the Nation’s Capital but still featured dramatic swings in temperature.  For example, high temperatures in Washington, D.C. fell from 67 degrees on January 4 to 32 degrees on January 6.  An “Alberta Clipper” brought DC residents 2.4” of snow on January 6 which lingered as high temperatures remained at or below freezing for three consecutive days.  In fact, the high temperature of only 26 degrees on January 8, 2015 was the coldest high temperature of the entire month.

Mid-Atlantic residents will justifiably remember last January’s record snowstorm as the month’s primary weather story.  However, there were a few significant swings in temperature then, such as a high of only 32 degrees on January 13 with a much milder high temperature of 53 degrees a day later.  High temperatures remained below 40 degrees for eight consecutive days in the Nation’s Capital from January 17 – 24, 2016, with below freezing temperatures on four of those days.  DC’s fourth largest snowstorm on record occurred on January 22-23 last year.

These dramatic temperature swings have been relatively common during the last few winters and Washingtonians are on the verge of another one.  Following yesterday’s high temperature of 57 degrees, high temperatures today will remain below average in the mid-30s, with light snow expected by evening.  Even colder temperatures are on tap the next few days in the Nation’s Capital.  My colleagues and I on the WUSA9 weather team will keep you apprised of the latest details in the weather forecast.