Drought Conditions Return

The Mid-Atlantic Region could use some rain  (Source: NOAA)

Moderate drought conditions have returned to the DC Metro Area for the first time since March 2018.  An exceptionally dry period over much of the Mid-Atlantic Region began this summer.  A total of only 2.26” of rain occurred in the Nation’s Capital since August 1.  That’s DC’s driest 2.5 month period since November 14, 2017 – January 31, 2018 (1.53”).

DC Area residents may recall that 2018 finished as DC’s wettest on record with an annual rainfall total of 66.28”.  That’s an astounding 26.54” above DC’s yearly average of 39.74”.  The exceptionally rainy weather pattern continued during the first seven months of 2019.  The Nation’s Capital had a rainfall surplus of 33.12” for the 15-month period from April 2018 – July 2019.  During that span, three months finished among the Top Ten wettest on record in addition to DC’s wettest November on record that occurred last year.

However, that rainy 15-month period followed an even longer stretch of abnormally dry weather.  Washington, D.C. accrued a rainfall deficit of 16.42” for the 32-month period from August 2015 through March 2018.  During that time, DC had four months that ranked among its Top 5 driest on record.  There was a 180° shift in DC’s weather pattern from exceptionally wet back to very dry.

With only 1.99” of rain for the entire month, August 2019 was DC’s first month to finish with less than 2” of rain since March 2018 (1.92”).  September 2019 finished as DC’s fourth driest with 0.25” and that was the driest overall month in the Nation’s Capital since March 2006.  With only 0.02” of rain so far this month, October has been exceptionally dry as well.

Since Washington, D.C. had an annual rainfall surplus of 5.32” through the end of July, this year won’t finish among DC’s driest.  The last two and a half months have evoked memories of other dry years, such as the 32-month period from mid-2015 through early-2018 or 2001-2002 when DC had a combined 64.28 of rain (15.2” below normal).

A total of 31.05” of rain has occurred in the Nation’s Capital since January 1.  It’s quite possible DC will ultimately finish with at least 39.74” of rain, making 2019 an “average” year.  That would mask how streaky the rainy and dry periods have been.  NOAA expects wetter than average conditions for the central and eastern United States in its extended forecast for October 20 – 26.  That’s definitely good news for the Mid-Atlantic Region.