Cinco De Mayo 2016: Chilly and Wet

Drier than average weather has characterized the Nation’s Capital for all of March and most of April.  However, since April 23 there has been a major shift in the weather pattern for the Mid-Atlantic Region bringing above average rainfall and below average temperatures.

  

There has been measureable rain at National Airport on ten of the last 13 days since April 23 – including our current streak of nine consecutive days.  That streak is poised to continue through Saturday and will put a significant dent in the rainfall deficit which had been 5.27” on April 30 (for the nine-month period that began August 1).  This sustained rainy period also helps build up water levels as the hotter summer months loom on the horizon.  Not since May 2003 have Washingtonians experienced a similar streak of wet weather during the spring in the Nation’s Capital.

During the last two weeks, there has been a great disparity in temperatures, including a four-day stretch where temperatures remained below 60 degrees in the Nation’s Capital (April 28 – May 1) – more characteristic of March.  On the flip side, the warmest day of the year occurred on April 26 when it was 86 degrees at National Airport.  Eleven of the 16 Mays since 2000 have included 90-degree heat in Washington, D.C., so the weather can heat up quickly this time of year.

People sometimes forget that May can be a streaky weather month in the Nation’s Capital.  Five of the last six Mays have been drier than average and the last six Mays have been warmer than average in Washington, D.C.  At the same time, three of the four wettest Mays to occur at National Airport have occurred since 2003 according to the National Weather Service. 

NOAA’s outlook for May calls for above average temperatures and an equal chance of above or below average precipitation.  So it’s important we make up as much of our modest rainfall deficit as possible during this wet stretch of weather.  That will put us in better shape with the summertime heat and humidity – characteristic of this part of the country – looming on the horizon.