Drought Conditions Envelop the Mid-Atlantic

Washington, D.C. (November 2016)

Many Washingtonians have been enjoying the milder than average temperatures this fall.  However, this fall has been unusually dry in the Mid-Atlantic Region.  Although six of the first eight months of 2016 were drier than average in the Nation’s Capital, the lack of rain has gotten more noticeable since September 1.

Washington, D.C.’s annual rainfall deficit is 6.76” and most of that amount (5.29”) is just since September 1.  Following the record heat of July and August, the warm and dry weather this fall have acerbated the dry conditions.  This week’s updated Drought Monitor Index shows moderate drought conditions now exist from central Pennsylvania through central Maryland into parts of the District of Columbia and Virginia.

Recent freezing temperatures brought an end to the growing season for the Mid-Atlantic Region.  However, the growing rainfall deficit is ominous since no significant rainfall is expected over the next several days.  The deficit will continue to grow as NOAA expects only near to slightly above rainfall for the Mid-Atlantic Region during the rest of November.

Unlike late summer and early fall, the tropics tend to get much quieter in November so, area residents can’t count on significant rainfall from a decaying tropical system.  One exception was the summer of 1999, which was significantly hotter and drier than average.  However, September 1999 brought about an abrupt end to that summer’s dryness when record rainfall occurred in association with former Hurricanes Dennis and Floyd.  Although Hurricane Matthew brought copious rainfall totals from Florida to North Carolina last month, no appreciable rainfall occurred in the DC Metro Region.

The last time 0.5” or more of rainfall occurred in Washington, D.C. was on September 29 when 1.02” of rain fell.  However, since September saw only 2.5” of rain for the entire month (more than an inch below average) the growing rainfall deficit remains a problem.  My colleagues and I on the WUSA9 weather team will keep you apprised of the latest forecasts and weather updates.