Tropical Storm Arthur, which was moving over the outer banks of North Carolina, was forecast to continue moving northeastward off the Mid-Atlantic coastline. At the same time, the tail of Arthur, basically a trough of low pressure, extended into the southeastern portion of the country. This also combined with a mid to upper level area of low pressure moving into the Tennessee Valley and a trough of low pressure moving into the eastern Gulf of Mexico which allowed for a south southwesterly flow across South Florida. This allowed for the Gulf coast sea breeze to push inland as the east coast sea breeze remained pushed up against the east coast. This eventually lead to the development of scattered to numerous showers and thunderstorms across all of South Florida. The primary impacts with these storms were heavy rainfall and associated flooding, frequent lightning strikes, small hail, and gusty winds.

Flood in PALM BEACH, FLORIDA
From 18-MAY-20 13:00:00 to 18-MAY-20 17:00:00 (EST-5)
Location: DELRAY BEACH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Several inches of rain, with measured amounts ranging from 4 to 8 inches, and locally higher amounts, caused flooding in portions of Boynton and Delray Beach. Broadcast media shared a video that showed flooding near the intersection of Congress Ave and Woolbright Rd in Boynton Beach. One car stalled while others turned around. The Weather Underground station KFLDELRA49 in the Sabal Lakes Community of Delray Beach measured 5.41 inches of rain whereas the Weather Underground station KFLDELRA71 near Lake Ida in Delray Beach measured 7.37 inches of rain.

Flood in MIAMI-DADE, FLORIDA
From 18-MAY-20 18:30:00 to 18-MAY-20 22:30:00 (EST-5)
Location: MIAMI
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

An off duty NWS Employee reported multiple reports of flooding, including a right lane flooded on I-95 at the intersection of I-95 and I-395 and significant street flooding along NE 11th Street and Biscayne Blvd. Waters accumulated several inches on the road, creating nearly impassable conditions due to repeated rounds of showers and thunderstorms.

Flood in MIAMI-DADE, FLORIDA
From 18-MAY-20 18:30:00 to 18-MAY-20 22:30:00 (EST-5)
Location: MIAMI
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Broadcast media reported multiple reports of flooding, including streets covered in several inches of water in Miami near NW 3rd Ave and NW 18th Street, due to repeated rounds of showers and thunderstorms.

Flood in PALM BEACH, FLORIDA
From 18-MAY-20 13:00:00 to 18-MAY-20 17:00:00 (EST-5)
Location: DELRAY BEACH
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

A picture reported on social media showed significant flooding in the parking lot of the Boys Farmers Market on South Military Trail due to heavy rainfall.

Heavy Rain in BROWARD, FLORIDA
From 18-MAY-20 14:00:00 to 18-MAY-20 15:00:00 (EST-5)
Location: DAVIE
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Broadcast media reported heavy rainfall associated with showers and storms in Davie, FL. Home surveillance cameras captured the moment a patio roof collapsed after a deluge of rain. Pieces of furniture were moving all over the patio. Fortunately, no one was injured.

Heavy Rain in BROWARD, FLORIDA
From 18-MAY-20 14:00:00 to 18-MAY-20 15:00:00 (EST-5)
Location: BISCAYNE GARDENS
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Broadcast media reported heavy rainfall associated with showers and storms near the 5200 block of Fletcher St in Hollywood, FL. Heavy rain caused a bedroom ceiling to collapse while a 5-year-old boy and an older relative were inside. The family living at the home said debris struck boy in the head. He was taken to the hospital and is expected to be okay.

Flash Flood in PALM BEACH, FLORIDA
From 18-MAY-20 14:00:00 to 18-MAY-20 17:00:00 (EST-5)
Location: OCEAN RIDGE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Several inches of rain, with measured amounts ranging from 3 to 6 inches, and locally higher amounts, caused flooding in portions of Boynton Beach and Ocean Ridge. Law enforcement reported Woolbright Road was closed from Federal Highway to the intracoastal waterway bridge due to heavy rainfall. The Weather Underground station KFLBOYNT1 near Bethesda Hospital East in Boynton Beach measured 5.43 inches of rain.

Hail in PALM BEACH, FLORIDA
From 18-MAY-20 13:25:00 to 18-MAY-20 13:25:00 (EST-5)
Location: WELLINGTON
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter reported nickel sized hail and wind gusts high enough to knock down some weak tree branches at Big Blue Trace and Wellington Trace in Wellington, FL.

Thunderstorm Wind in COLLIER, FLORIDA
From 18-MAY-20 16:37:00 to 18-MAY-20 16:37:00 (EST-5)
Location: EAST NAPLES
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A wind gust of 58 mph (50 kt) was measured by the Earth Networks Mesonet site (NPLHH) at the Hamilton Harbor Yacht Club in Naples.

Lightning in COLLIER, FLORIDA
From 18-MAY-20 16:50:00 to 18-MAY-20 16:50:00 (EST-5)
Location: NORTH NAPLES
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Broadcast media reported a house fire due to a lightning strike near the corner of Ridge Dr and East Ave near North Naples. The family had safely evacuated the home by the time crews arrived on scene. Naples Fire-Rescue Department confirms a lightning strike hit the roof of a home, causing the flames. Damage totals are estimated.

Thunderstorm Wind in COLLIER, FLORIDA
From 18-MAY-20 16:55:00 to 18-MAY-20 16:55:00 (EST-5)
Location: MARCO IS ARPT
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 1.00K
Reported by: Public

The public reported 1-inch tree limbs broken and roof shingles blown off near the area of Hammock Bay Golf and Country Club due to a thunderstorm.

Flood in COLLIER, FLORIDA
From 18-MAY-20 17:00:00 to 18-MAY-20 19:00:00 (EST-5)
Location: (APF)NAPLES MUNI ARP
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Reports and pictures of street flooding were reported via social media at the intersection of Tamiami Trail and Ohio Drive due to heavy rainfall.

Flood in MIAMI-DADE, FLORIDA
From 18-MAY-20 18:30:00 to 18-MAY-20 21:30:00 (EST-5)
Location: KEY BISCAYNE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

An off duty NWS Employee reported significant flooding at the intersection of Mashta Drive and Allendale Road in Key Biscayne due to repeated rounds of showers and thunderstorms across the area.