Notable June severe weather outbreaks

 

Hail observed in southern Maryland (Courtesy: Kristen Leitch, June 2018)

June has the second highest average annual number of tornadoes (243) in the United States according to NOAA.  Severe weather is defined as a thunderstorm that has any of the following: hail 1” in diameter or greater, wind gusts of at least 58 mph, or a tornado.  The Mid-Atlantic Region has seen many severe weather outbreaks during the month of June.  Below are some of the more significant ones that have occurred locally.

2019: June 2 was an active weather day in the D.C. Metro Area with multiple reports of large hail.  Hail as large as 2” in diameter was reported in Damascus, Maryland, as well as 1” diameter hail at the White House.  Having widespread large hail reports in the D.C. Metro Area is rather uncommon compared to other parts of the country.

2016:  Several dozen severe weather reports occurred on June 21 and included large hail, high wind and a tornado.  An EF-0 tornado with estimated wind speeds of 80 mph traveled more than 12 miles in Howard County, Maryland, where minor damage was reported.  Hail nearly 2” in diameter fell at Dulles Airport and several other locations in the D.C. Metro Area.  Also, less than a week earlier, several cases of hail at least 2” in diameter occurred in north central Virginia, including the town of Bluemont in Loudoun County on June 16.

2015:  Hail 3” in diameter was reported on June 23 in the Baltimore suburb of Cockeysville, while 4” diameter hail was reported in Timonium, Maryland.  That nearly tied the Maryland state record for largest hail of 4.5”.  According to the National Weather Service, the last time 4” diameter hail was observed in Maryland was in 1999.

2013: A total of six EF-0 tornadoes developed on June 13 in the DC Metro Area.  Although they were all relatively weak, some occurred in heavily traveled parts of Montgomery and Charles counties in Maryland where minor damage was observed.  This was also one of the wettest June’s on record in the Nation’s Capital, with a monthly total of 9.97” of rain at National Airport.

2008:  One of the more active severe weather days on record in the Nation’s Capital occurred on June 4.  Unlike derecho day on June 29, 2012, that featured a singular destructive event, there were multiple rounds of severe weather on this date.  The first round was a powerful squall line that passed through the DC Metro Area in the mid-afternoon.  Later that evening, several supercell thunderstorms developed and some produced tornadoes.

Weather Quiz

 

Hurricane Dorian, Category 5, September 2019 (Source: NOAA)

True or False.

June is the only month of the Atlantic hurricane season with no observed Category 5 hurricanes.

The Unofficial Start to Summer

 

A warm June morning, Avenel Park, Potomac, MD

May 2023 finished as the ninth driest on record in the nation’s capital with only 1.34” of rain.  That made it DC’s driest since 1999.  It was also a cooler than average month with an average temperature (combining daily high/low temperatures) that was 2.2° cooler than average.  It’s ironic that DC was both cooler and much drier than average since being cooler than average in May is often a function of a lot of cloudy and rainy weather.

NOAA’s Climate Prediction Center expects June to feature near average temperatures in the nation’s capital with near average rainfall.  Meteorological summer is comprised of the three-month period of June, July and August.  Daily average high/low temperatures in Washington, D.C. rise from 81°/63° on June 1 to 89°/71° on June 30.  D.C.’s hottest June temperature on record is 104° and occurred on June 29, 2012.  Meanwhile, DC’s coolest June temperature is 43° and occurred on June 2, 1897.

Six of the 10 June’s between 2003 and 2012 were cooler than average in the nation’s capital, while seven of the 10 since then were warmer than average.  The earliest in the season it’s been 100° in the nation’s capital was on June 5, 1925. 

According to NOAA, June is DC’s second wettest month of the year with an average rainfall of 4.20”.  Three of DC’s wettest June’s on record occurred in the last 17 years.  That includes D.C.’s rainiest June in 2006 and second rainiest June in 2015.  By comparison, June 2017 was D.C.’s third driest with only 1.13”.

Residents of the D.C. Metro Area have also endured severe thunderstorms in June.  For example, Maryland’s second strongest tornado occurred on June 2, 1998 when an F4 tornado touched down in Frostburg.  The D.C. Area’s infamous “derecho” occurred nearly 11 years ago on June 29, 2012, and caused widespread wind damage and power outages.  More recently, multiple of severe hail (1”/+ in diameter) were reported on June 2, 2019.  

Aside from today potentially being the first 90° day of the year in the nation’s capital, below average temperatures are expected over the next one to two weeks.  No widespread severe weather is expected either over the next week.