A deep southerly flow of tropical moisture was in place over southeast MA with precipitable water values in excess of 2 inches on the south coast. A frontal wave along the coast provided strong low level convergence and that combined with upper divergence from the right entrance region of a 110 knot upper level jet to produce very severe weather for Cape Cod.  Three tornadoes occurred!  Prior to these, there had only been three recorded tornadoes since 1950.  Outside of the tornado area, damage surveys showed that strong microburst winds caused straight-line damage.

Tornado in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 10:57:00 to 23-JUL-19 11:07:00 (EST-5)
Location: HYANNIS PORT
Tornado F-scale: EF1
Property damage: 1.20M
Crop damage: 0.00K
Reported by: NWS Storm Survey

A waterspout moved onshore just west of Kalmus Beach in Barnstable, MA at 1157 AM EDT (1057 AM EST). Winds gusted to 91 mph at a mesonet observation site at Kalmus. They had shifted from southeast to west-northwest with the passage of the tornado.  The tornado continued moving northeastward at about 35 mph. The damage was discontinuous but where the tornado touched down, the damage was quite significant, with winds estimated as high as 110 mph.
The roof of a motel on the south side of Main Street in West Yarmouth was completely peeled off.  Additional significant tornado damage occurred just southwest of the Dennis-Yarmouth Regional High School, particularly along Hazelmoor Road from Violet Glen Road to Vine Brook Road.  Dozens of large trees were uprooted and a few were snapped off.  Another house had a hole in the roof from a fallen tree.
The tornado then lifted.  However, severe straight-line wind damage was observed from West Dennis eastward to West Harwich.  Numerous large trees were uprooted, consistent with 90 mph gusts or greater.
Amazingly, no injuries were reported with the storm.  Cleanup of roads cost approximately $434,000 in Yarmouth. That does not count damage to homes or private claims.

Tornado in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:10:00 to 23-JUL-19 11:15:00 (EST-5)
Location: HARWICH
Tornado F-scale: EF1
Property damage: 3.60M
Crop damage: 0.00K
Reported by: NWS Storm Survey

The same supercell storm that produced the Barnstable-Yarmouth tornado went on to touch down again near the center of Harwich, MA at 1210 PM EDT (1110 AM EST). The initial touchdown was just east of Harwich Elementary School, just south of Parallel Street.  It moved northeast through Harwich Center, passing just south of a golf course, and lifted in East Harwich in the Vicinity of Queen Anne Road.  At least 150 hardwood trees were either uprooted or snapped.  A few homes also had shingles that were ripped off.  Wind gusts were estimated as high as 110 mph, which is on the high end of the Enhanced Fujita EF-1 ranking.  Harwich spent $1.2 million on cleanup of roads.  That figure is estimated to be one-third of the total costs, when individual homeowner claims are taken into account.
The tornado then lifted.  However, severe straight-line wind damage was observed in Chatham.  Numerous large trees were uprooted, consistent with 90 mph gusts or greater.

Tornado in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:00:00 to 23-JUL-19 11:01:00 (EST-5)
Location: WEST YARMOUTH
Tornado F-scale: EF1
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A brief and narrow tornado occurred in West Yarmouth and was on the ground at the very same time as another tornado was moving toward South Yarmouth!
The tornado touched down on Yacht Avenue and Schooner Street in West Yarmouth and traveled east approximately one-quarter mile before lifting on Egg Harbor Road, just after Pine Cone Drive.  The path width was approximately 50 yards.  Numerous pine trees were snapped near their bases.  Tree tops appeared twisted.  Residents reported seeing swirling motion.  NWS Doppler Radar showed a tornado debris signature with this storm, indicating that some trees and branches were lofted into the air.  This tornado was only on the ground for one minute, between noon and 1201 PM EDT (1100 and 1101 AM EST).  It lifted as it approached the south end of the Bass River.
Although a brief and very shallow waterspout was observed over the southern part of the Bass River, the damage in West Dennis just to the east of Wrinkle Point was considered to be from strong straight line downburst winds.

Thunderstorm Wind in DUKES, MASSACHUSETTS
From 23-JUL-19 10:25:00 to 23-JUL-19 10:25:00 (EST-5)
Location: TISBURY
Magnitude: 60.00 EG
Property damage: 1.50K
Crop damage: 0.00K
Reported by: Amateur Radio

In West Tisbury, two trees were down on Lamberts Cove Road.  One tree and wires were down on State Road.

Thunderstorm Wind in DUKES, MASSACHUSETTS
From 23-JUL-19 10:30:00 to 23-JUL-19 10:30:00 (EST-5)
Location: OAK BLUFFS
Magnitude: 50.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Amateur Radio

In Vineyard Haven, a tree and wires were reported down on California Avenue and on Hudson Avenue.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 10:38:00 to 23-JUL-19 10:38:00 (EST-5)
Location: POPPONESSET BEACH
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio reported a wind gust to 58 mph in the Popponesset section of Mashpee.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 10:40:00 to 23-JUL-19 10:40:00 (EST-5)
Location: MASHPEE
Magnitude: 50.00 EG
Property damage: 1.50K
Crop damage: 0.00K
Reported by: Amateur Radio

In Mashpee, multiple trees were reported down across the town.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 10:48:00 to 23-JUL-19 10:48:00 (EST-5)
Location: HYANNIS PORT
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A tree was down on wires on Barnstable Road. A large branch was down in front of a hotel on Pitchers Way. Wires were reported down on Scudder Avenue.  A tree was down on Ocean Avenue.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:01:00 to 23-JUL-19 11:01:00 (EST-5)
Location: HYANNIS
Magnitude: 50.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Amateur Radio

In Hyannis, a tree was down on Gosnold Street at Old Colony Road.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:05:00 to 23-JUL-19 11:05:00 (EST-5)
Location: WIANNO
Magnitude: 65.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Amateur Radio

In the Osterville section of Barnstable, two small boats were flipped over in West Bay. A tree was down on wires on Scudder Road.  Several large trees and many large branches were down on Wianno Avenue.  Storm survey determined this wind damage to be straight-line.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:14:00 to 23-JUL-19 11:14:00 (EST-5)
Location: WEST BREWSTER
Magnitude: 65.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Amateur Radio

In Brewster, a large tree was down on Stony Brook Road. A tree and power lines were down on Run Hill Road.  Numerous other trees were down throughout the town.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:30:00 to 23-JUL-19 11:30:00 (EST-5)
Location: SOUTH ORLEANS
Magnitude: 61.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Amateur radio operators reported trees down on Route 28 Southbound.  Wires were down on Main Street.  A tree was down on wires on Blue Heron Way.  A large tree was down on Quanset Road. Wires were down on Karen Lane.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:02:00 to 23-JUL-19 11:06:00 (EST-5)
Location: WEST DENNIS
Magnitude: 78.00 EG
Property damage: 2.60M
Crop damage: 0.00K
Reported by: NWS Storm Survey

A NWS survey team determined that although a weak, shallow waterspout was observed over the southern end of the Bass River, the damage observed in West Dennis was from straight-line microburst winds, estimated at 90+ mph. Media and amateur radio contributed to the following reports, as well.  Numerous trees and wires were snapped or downed at Wrinkle Point.  Trees and wires were down on Loring Avenue. Wires were down on Corporation Road.  Trees, wires, and a utility pole were down on Pleasant Street.  Wires were down on a car on Depot Street at Vester Drive.  Power lines were down on Old Wharf Road.  Trees down on Sunset Drive.  There were many others. State Emergency Management reported that the cost to Dennis just for cleaning up the roads was a whopping $860,000.  Total estimates were approximately triple that figure, when accounting for individual homeowner and business claims.

Thunderstorm Wind in BARNSTABLE, MASSACHUSETTS
From 23-JUL-19 11:15:00 to 23-JUL-19 11:20:00 (EST-5)
Location: CHATHAM
Magnitude: 78.00 EG
Property damage: 1.00M
Crop damage: 0.00K
Reported by: NWS Storm Survey

In Chatham, a NWS survey found numerous large trees uprooted, consistent with 90+ mph microburst straight line winds, which is what remained after the Harwich tornado lifted. Two utility poles were leaning on Morris Island Road with one snapped in half and wires hanging low to the ground.  A mesonet site reported a gust to 85 mph at 1115 AM EST (1215 PM EDT). Emergency management cited $426,000 in costs for the town to clean debris from roadways.  Total damage estimates are much higher, accounting for individual homeowner and business claims.