Summertime Storms

The summer of 2014 has had several unique characteristics as we reach the official midpoint of meteorological summer – July 15^th (meteorological summer being June 1^st through August 31^st).  Many of the weekends during late spring and summer have been both sunny with relatively comfortable relative humidity.  That’s not to say there haven’t been some hot days as a record high of 97 degrees was set in the Nation’s Capital on June 17^th. 

July has gotten off to a fairly stormy start in the Mid-Atlantic Region.  In fact, according to National Weather Service records, today will be the 8^th day during the first half of July that severe weather has been observed in the Mid-Atlantic Region.  These summertime storms and bouts of extreme heat can be largely attributed to the position of the “Bermuda High”: a semi-permanent area of high pressure common during the summer off the East coast of the United States.  It helps pump ample amounts of warm, humid weather northward from the Deep South during the summer months.

Some may have heard the term “polar vortex” mentioned again during the last few days and thought back to how cold the winter was for much of the Eastern United States.  The truth is the “polar vortex” is also a semi-permanent feature that hovers above the North Pole and helps regulate cold air.  The jet stream will take a temporary plunge across the Central and Eastern United States the next few days, bringing cooler than average weather from the Midwest to the Mid-Atlantic and Northeast. 

The leading edge of the cooler air – the cold front that is passing through the Mid-Atlantic Region today – caused the heavy showers and thunderstorms that developed this afternoon.  The “Bermuda High” and “Polar Vortex,” while interesting, are not new weather phenomena and should not cause alarm once better understood.  So Washingtonians should enjoy the sunny, fall like weather tomorrow and Thursday with highs only in the low 80s – typical of early to mid September.  Hazy, hot and humid weather will be back soon.