A tornado hit Kent Island in the middle of the night last night. The Mount Holly, NJ National Weather Service declared it an EF2 tornado at ~125mph, but the photos of damage done to Kent Island indicate it is the strongest tornado to strike Maryland since the F4 April, 2002 LaPlata tornado that also went across the bay to be an F3 tornado in Dorchester County, MD.
— NWS Eastern Region (@NWSEastern) July 24, 2017
Photos this morning showed extensive damage to some houses, others shifted off their foundations, cars and boats tossed around, and numerous large trees shredded or uprooted. Everything can be found on social media, but I wanted to comment that this appears to me to be another tornado forming as a result of the sudden friction difference between water and land. It’s widely taught on television during approaching hurricanes that when hurricanes strike land, tornados often form within the rain bands due to the sudden encounter of friction with land. It’s actually the friction difference and tropical systems that still have strong circulation that are later exiting the continent onto the ocean (which happens in some cases) also exhibit the same behavior.
The same appears to be true with “regular” thunderstorms or thunderstorm cells of a non-tropical origin – difference in friction can turn them into full-blown mesoscale low pressure systems with a strong tornado. Our local National Weather Service noted on a now defunct web page that the LaPlata tornado in 2002 was likely initiated by the strong thunderstorm crossing the Potomac River from Virginia. With the Kent Island tornado, the thunderstorm was strong in Prince George’s county (there was a report of a tree down in Glenn Dale), then went through Anne Arundel County, entered the Chesapeake Bay non-tornadic and by the time it was on Kent Island only 4.3 miles later, was obviously a full-blown mesocyclone with a strong tornado. It seems likely to me that the thunderstorm exiting the western shore of Maryland onto the Chesapeake Bay was a factor in initiating and forming the powerful tornado.
It’s fortunate that nobody was killed in this storm.
Justin Berk stated it was likely an EF0 or EF1 tornado around 1pm today after photos of damage clearly indicated it was EF2 or higher.
— Justin Berk (@JustinWeather) July 24, 2017
There were indications this was a major tornado (EF3), as exterior walls of houses fully collapsed, but its dependent on the construction of the house and that is a subjective call after the fact. The NWS usually goes conservative in their estimate, so the EF2 rating is not that surprising. Berk later stated Doppler radar estimate of winds was 86mph and that is presumably why he felt it was an EF0 or EF1.
Before the NWS assessment came out, a number of outlets stated the maximum wind gust was 68mph. I tracked down this obviously erroneous information and found that it came from a buoy on the western shore near Eastport and that this was the highest wind speed recorded in the local storm reports from the Sterling, VA National Weather Service forecast area. Why news outlets were saying this was the wind speed on Kent Island is beyond me, but it’s further proof that the mainstream media refuses to do its job and warrants being given the name “fake news”.
NWUS51 KLWX 240533
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
133 AM EDT MON JUL 24 2017
..TIME… …EVENT… …CITY LOCATION… …LAT.LON…
..DATE… ….MAG…. ..COUNTY LOCATION..ST.. …SOURCE….
0124 AM TSTM WND GST 1 E EASTPORT 38.97N 76.46W
07/24/2017 M68 MPH ANZ532 MD BUOY
EVENT NUMBER LWX1702513