Mean layer troughing positioned over SE Georgia as upper level divergence increased within the right rear quadrant of the upper level jet stream. Lingering outflow boundaries and active sea breezes in concert with a very moist and unstable airmass combined with the dynamical convective triggers to support widespread flooding and isolated severe storms during the afternoon and evening.

Heavy Rain in DUVAL, FLORIDA
From 20-AUG-12 22:55:00 to 20-AUG-12 22:55:00 (EST-5)
Location: VENETIA
Reported by: ASOS

Naval Air Station Jacksonville measured a 12 hour rainfall of 3.84 inches. The one hour total of 3.45 inches occurred between 3 and 4 pm.

Heavy Rain in CLAY, FLORIDA
From 20-AUG-12 22:55:00 to 20-AUG-12 22:55:00 (EST-5)
Location: BELLAIR
Reported by: Public

A storm total amount of 3.17 inches was measured.

Heavy Rain in CLAY, FLORIDA
From 20-AUG-12 22:55:00 to 20-AUG-12 22:55:00 (EST-5)
Location: MEADOWBROOK
Reported by: Public

The public measured 2.93 inches of storm total rainfall.

Heavy Rain in DUVAL, FLORIDA
From 20-AUG-12 22:55:00 to 20-AUG-12 22:55:00 (EST-5)
Location: YUKON
Reported by: Public

The public measured 4.86 inches of rainfall.

Heavy Rain in DUVAL, FLORIDA
From 20-AUG-12 22:55:00 to 20-AUG-12 22:55:00 (EST-5)
Location: (CRG)CRAIG FLD JACKS
Reported by: ASOS

Craig Airport measured a 12 hour rainfall of 2.68 inches. One hour rainfall accumulation was 2.43 inches between 3 pm and 4 pm.

Hail in CLAY, FLORIDA
From 20-AUG-12 13:30:00 to 20-AUG-12 13:30:00 (EST-5)
Location: PENNEY FARMS
Magnitude: 0.88 
Reported by: Post Office

The Green Cove Springs Post Office observed nickel size hail near State Road 16 and County Road 218.

Thunderstorm Wind in DUVAL, FLORIDA
From 20-AUG-12 15:53:00 to 20-AUG-12 15:53:00 (EST-5)
Location: FT GEORGE IS
Magnitude: 45.00 EG
Property damage: 0.50K
Crop damage: 0.00K
Reported by: Emergency Manager

A tree was blown down over the road in Cedar Point. The cost of debris removal was estimated.

Thunderstorm Wind in COLUMBIA, FLORIDA
From 20-AUG-12 11:40:00 to 20-AUG-12 11:40:00 (EST-5)
Location: FT WHITE
Magnitude: 50.00 EG
Reported by: State Official

Trees were blown down in Fort White. One damaged a home. The time of the event was based on radar.

Thunderstorm Wind in ST. JOHNS, FLORIDA
From 20-AUG-12 13:50:00 to 20-AUG-12 13:50:00 (EST-5)
Location: VILANO BEACH
Magnitude: 50.00 EG
Reported by: Post Office

Trees were blown down along Sherwood Avenue.

Flood in DUVAL, FLORIDA
From 20-AUG-12 14:45:00 to 20-AUG-12 16:30:00 (EST-5)
Location: WESCONNETT
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Widespread areal flooding occurred across downtown Jacksonville from the Westside of town to Mandarin, and northward to Arlington and the Northside. At 3:45 pm, Duval County Emergency Management reported cars were stranded due to flooded roads throughout the San Marco area. At 3:55 pm, law enforcement reported the Powers Road from Toledo Road to University Blvd was closed due to flooding. At 4 pm, emergency management reported flooding along Blanding Blvd near Interstate 295 in Argyle. At 4 pm, emergency management also stated a roof collapsed at an apartment complex along San Jose Blvd due to heavy rainfall. At 4:06 pm, the media reported a car was trapped by flood waters in Argyle. At 4:18 pm, the media reported a home was flooded in Ortega with water rescues by fire officials. At 4:18 pm, emergency management reported water was entering a home in Englewood. The car of the homeowner was flooded and there was widespread street flooding in the area. At 4:26 pm, a spotter reported a drainage ditch overflowed and caused flooding on Harlow Blvd. The spotter also measured 3.2 inches of storm total rainfall. At 4:53 pm, emergency management reported a vehicle stuck in flood waters in San Marco. At 5:01 pm, emergency management reported a sinkhole behind an apartment complex near Naval Air Station Jacksonville. At 5:11 pm, emergency management reported water entered a home near Bowden Road close to University Blvd. At 5:12 pm, emergency management reported water entered a home in San Marco. AT 5:12 pm, emergency management reported street flooding over Sabena Road near University Blvd. At 5:15 pm, the media reported significant inundation due to flooding at the intersection of McCoys Creek Blvd and Stockton Street in downtown Jacksonville. At 5:15 pm, the media reported inundation due to flood waters near the intersection of Roosevelt Blvd and South Edgewood Ave in the Avondale area of downtown Jacksonville. At 5:16 pm, emergency management reported flooded streets in southside Jacksonville between Atlantic Blvd and Beach Blvd near University Blvd South. At 5:18 pm, emergency management reported a vehicle stuck in flood waters in the southbound lane of the approach to the Buckman Bridge. At 5:25 pm, emergency management reported that north Main Street and Zoo Parkway were closed due to flooding and the concrete cracking underneath an overpass and shifting. At 5:27 pm, emergency management reported a sinkhole on University Blvd North and Arlington Road. At 5:30 pm, emergency management reported a vehicle stuck in flood waters in the San Jose area of Jacksonville. The cost of damage was estimated, and it is likely grossly underestimated.

Lightning in FLAGLER, FLORIDA
From 20-AUG-12 15:15:00 to 20-AUG-12 15:15:00 (EST-5)
Location: BEVERLY BEACH
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Power lines were down across A1A due to a lightning strike. The cost of repair was estimated.

Lightning in ST. JOHNS, FLORIDA
From 20-AUG-12 13:30:00 to 20-AUG-12 13:30:00 (EST-5)
Location: SAMPSON CHURCH
Property damage: 2.00K
Crop damage: 0.00K
Reported by: State Official

A lightning strike hit a home on Tortuga Bay Drive which caused a structure fire. The time of the incident was based on lightning data. The cost of damage was estimated.