SW steering flow and cooler 500 mb temperatures of -7C to -9C combined moisture and instability over the area which triggered strong to pulse severe storms along sea breeze and outflow mergers.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS JAX wrote it up.
SW steering flow and cooler 500 mb temperatures of -7C to -9C combined moisture and instability over the area which triggered strong to pulse severe storms along sea breeze and outflow mergers.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Jacksonville, FL wrote its last area forecast discussion before the first event at Aug 17, 2:55 PM EST, 1 minute earlier.
Area Forecast Discussion National Weather Service Jacksonville FL 355 PM EDT Fri Aug 17 2018 .NEAR TERM...(Rest of today-tonight)... Scattered to numerous showers and storms will continue to develop and propagate north to northeast in an unstable and moist airmass. Mesoanalysis showed SBACPE of 3000-4000 J/kg and PWATs of 2 inches. So enough instability and DCAPE to produce gusty winds up to 40- 60 mph and high rainfall rates to produce localized flooding. Storms may tend to shift on off to the north-northeast and move toward the coast in the evening hours. Most activity will be dissipated by 11pm-midnight. Overnight lows tonight in mid 70s. .SHORT TERM.../Saturday through Monday... Mid-upper ridge will remain nearly stationary across the central FL peninsula during the weekend with some drier air moving in from the south and southeast affecting central and srn parts of the forecast area. GFS shows PWATs generally in the 1.4 to 1.6 inch range with this dry air helping to curtail POPs a bit. Deep southwest flow will allow for dominant west coast seas breeze during the day. At this time...anticipate rain chances about 20-30 percent for northeast FL and generally in the chance range (30-40 percent) for southeast GA this weekend. Slightly above normal temperatures will prevail. Sunday night into Monday...guidance is suggesting a surge of moisture coming up from the south which should enable a better chance of showers and storms for Monday afternoon and actually for northeast FL with POPs to about 30-40 percent while southeast GA values shift downward to around the 20-30 percent range. Highs in the lower 90s forecast for Monday. .LONG TERM...Tuesday through Friday... The general trend for the extended is that a mid to upper level trough will dig into the ern U.S./East Coast with an associated cold front and prefrontal trough making as far as south as the southeast GA area and coastal SC. Relatively moist, and deep southwest to west wind flow will produce scattered showers and storms each day up through late Wed. Drier air may move in from the northwest, per the GFS, by Wed evening and Thu but not all the way through the region. For now...with the Euro model showing much wetter conditions as the front stalls near the area will maintain at least climo POPs Thu and Fri. Temperatures will remain at or slightly above normal through the period. && .AVIATION.. Mainly VFR conds outside of convection for the TAF sites. Scattered sea breeze convection as it moves inland with best chances at JAX/VQQ/GNV and have kept TEMPO MVFR CIGS/VSBYS and gusty winds to around 30 knots possible. Shower chances end earliest at the coast between 22-00z, while convection chances will linger at inland TAF sites until 00-02z. Lingering high clouds during the overnight hours with some light fog possible at GNV/VQQ but chances too low to include in the TAFs at this time. && .MARINE... High pressure ridge axis will remain mainly south of the waters through middle of next week providing for southerly flow over the local waters and a chance of a shower and/or thunderstorm. SSW winds 10-15 kts will prevail over the waters, becoming onshore near the coast with the sea breeze each afternoon. Combined seas 3 ft or less. Rip Currents: Moderate risk of rip current rest of today. Lower risk for SE GA expected this weekend with moderate risk for NE FL where longer period ESE swells will continue. && .PRELIMINARY POINT TEMPS/POPS... AMG 73 91 73 91 / 50 30 20 40 SSI 77 90 76 90 / 30 10 10 20 JAX 74 92 74 93 / 20 30 10 20 SGJ 75 91 74 90 / 10 20 10 20 GNV 73 92 74 93 / 30 30 0 20 OCF 73 92 73 93 / 20 20 10 30 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. && ARS
Special Weather Statement National Weather Service Jacksonville FL 240 PM EDT FRI AUG 17 2018 FLZ040-171915- Marion FL- 240 PM EDT FRI AUG 17 2018 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN MARION COUNTY UNTIL 315 PM EDT... At 240 PM EDT, Doppler radar was tracking a strong thunderstorm near Fort McCoy. This storm was nearly stationary. Wind gusts of up to 40 can be expected along with frequent lightning. Locations impacted include... Fort McCoy and Burbank. LAT...LON 2946 8201 2946 8178 2927 8178 2927 8201 TIME...MOT...LOC 1840Z 208DEG 2KT 2936 8189 MCGINNIS
Special Weather Statement
National Weather Service Jacksonville FL
259 PM EDT FRI AUG 17 2018
FLZ036-171930-
Alachua FL-
259 PM EDT FRI AUG 17 2018
...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL ALACHUA COUNTY UNTIL
330 PM EDT...
At 258 PM EDT, Doppler radar was tracking a strong thunderstorm over
Newnans Lake, or 7 miles east of Gainesville, moving northwest at 10
mph.
Wind gusts up to 50 mph can be expected along with frequent
lightning.
Locations impacted include...
Gainesville, Gainesville Airport, Newnans Lake and University Of
Florida.
LAT...LON 2968 8212 2963 8213 2959 8219 2966 8241
2982 8230
TIME...MOT...LOC 1858Z 112DEG 9KT 2966 8221
MCGINNISSpecial Weather Statement
National Weather Service Jacksonville FL
314 PM EDT FRI AUG 17 2018
FLZ025-032-171945-
Inland Duval FL-Clay FL-
314 PM EDT FRI AUG 17 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CLAY COUNTY UNTIL
345 PM EDT...
At 314 PM EDT, Doppler radar was tracking a strong thunderstorm near
Middleburg, moving northwest at 10 mph.
Wind gusts up to 50 mph can be expected along with locally heavy
rainfall.
Locations impacted include...
Middleburg, Doctors Inlet, Lakeside, Kingsley, Oakleaf Plantation,
Camp Blanding, Bellair-Meadowbrook Terrace, Penney Farms and Asbury
Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3001 8175 2994 8187 2995 8205 3019 8205
3019 8175
TIME...MOT...LOC 1914Z 137DEG 26KT 3003 8185
MCGINNISSpecial Weather Statement
National Weather Service Jacksonville FL
341 PM EDT FRI AUG 17 2018
FLZ023-025-031-032-172015-
Inland Duval FL-Baker FL-Bradford FL-Clay FL-
341 PM EDT FRI AUG 17 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BRADFORD...
SOUTHEASTERN BAKER...NORTHWESTERN CLAY AND SOUTHWESTERN DUVAL
COUNTIES UNTIL 415 PM EDT...
At 340 PM EDT, Doppler radar was tracking a strong thunderstorm near
Maxville, or 7 miles northwest of Middleburg, moving north at 10 mph.
Wind gusts up to 50 mph can be expected along locally heavy rainfall.
Locations impacted include...
Middleburg, Macclenny, Glen St. Mary, Maxville, Baldwin and Lawtey.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 3000 8199 2999 8208 3011 8215 3012 8214
3014 8214 3014 8217 3026 8224 3031 8205
3027 8205 3033 8198 3034 8196 3005 8188
TIME...MOT...LOC 1940Z 161DEG 24KT 3011 8202
MCGINNISSpecial Weather Statement
National Weather Service Jacksonville FL
344 PM EDT FRI AUG 17 2018
FLZ032-033-172015-
Clay FL-Inland St. Johns FL-
344 PM EDT FRI AUG 17 2018
...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN ST. JOHNS AND
NORTHEASTERN CLAY COUNTIES UNTIL 415 PM EDT...
At 343 PM EDT, Doppler radar was tracking a strong thunderstorm near
Green Cove Springs, moving north at 10 mph.
Wind gusts up to 50 mph can be expected along with locally heavy
rainfall.
Locations impacted include...
Green Cove Springs, Fruit Cove, Fleming Island and Switzerland.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 2993 8156 2994 8166 3012 8176 3013 8169
3012 8168 3013 8163 3013 8160 3012 8157
3012 8154 3010 8154 3010 8152 2996 8148
TIME...MOT...LOC 1943Z 163DEG 14KT 3001 8160
MCGINNISSpecial Weather Statement National Weather Service Jacksonville FL 354 PM EDT FRI AUG 17 2018 FLZ025-172030- Inland Duval FL- 354 PM EDT FRI AUG 17 2018 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN DUVAL COUNTY UNTIL 430 PM EDT... At 353 PM EDT, Doppler radar was tracking a strong thunderstorm near Normandy, or 10 miles west of Jacksonville, moving northwest at 15 mph. Wind gusts of 40 to 50 mph can be expected along with locally heavy rainfall. Locations impacted include... Cecil Field, Cisco Gardens, Normandy, Baldwin, Jacksonville Heights and Whitehouse Air Field. PRECAUTIONARY/PREPAREDNESS ACTIONS... Frequent cloud to ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle. && LAT...LON 3019 8195 3033 8198 3048 8182 3020 8168 TIME...MOT...LOC 1953Z 151DEG 14KT 3030 8183 MCGINNIS
The Jacksonville radar (KJAX), 15 km away, was scanning. The volume nearest the first event began at 19:56 UTC.
7 thunderstorm wind, 1 lightning. Local standard time, as filed.
A wire was blown down near Edgewood Avenue and W 12th Street. The time of damage was based on radar imagery and the cost of damage was estimated.
A tree was blown down on NW 46th Street. The time of damage was based on radar and the cost was estimated.
A spotter estimated wind gusts near 60 mph which blew down some branches. Pea size hail was also observed. The cost of tree damage was estimated.
Thunderstorm wind gusts damaged some property in the Holling Woods Estate Neighborhood.
Numeorus trees were blown down across the county. The time of damage was based on radar.
A tree was blown down near the intersection of County Road 121 and Charles Green Road. The cost of damage was estimated.
A couple trees and several limbs were blown down near the Oleno State Park ranger office. The time of damage was based on radar.
Lightning struck a tree and caused a small fire near US Highway 1 and Wade Drive. The cost of damage was unknown but estimated for the event to be included in Storm Data.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2018Every state in 2018This day in weather historyWarnings in Florida, August 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 781951, 781952, 781957, 781953, 781954, 781955, 781956, 781950.