A surface front and drier air was settling southward across SE GA, with a differential heating boundary across NE FL near I-10 due to cirrus blow-off from storms in Appalachee Bay. Strong to severe storms formed across NE FL due to heating and interactions with the differential heating boundary and sea breezes.
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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.
A surface front and drier air was settling southward across SE GA, with a differential heating boundary across NE FL near I-10 due to cirrus blow-off from storms in Appalachee Bay. Strong to severe storms formed across NE FL due to heating and interactions with the differential heating boundary and sea breezes.
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 Jun 16, 2:15 PM EST, 2 hours 5 minutes earlier.
Area Forecast Discussion National Weather Service Jacksonville FL 315 PM EDT Wed Jun 16 2021 .NEAR TERM [Through Tonight]... A near stationary front, evident by a sharp moisture/instability gradient in the latest surface analysis, stretches northeastward from near Panama City Beach into the Coastal Carolinas. Meanwhile, deep convection ahead of this boundary over the northeastern Gulf has spread dense anvil cirrus across portions of northeast FL, generally over the frontal zone. This cirrus has limited heating early this afternoon and thus delayed much in the way of initiation along the front. In the warm sector, generally south of a line from Newberry to Ponte Vedra, thinner cirrus and more insolation will allow an initial round of scattered storms to develop through the late afternoon. With the thicker cirrus to the north, convection along the front may be delayed until later this evening when Gulf sea breeze collides with the front and stronger forcing for ascent reaches overlaps it. CAMs are honing in on that solution and are resolve a strong segmented line of convection propagating southward along resultant outflow across northeast FL through the evening hours. Lapse rates aloft will foster a hail risk with these storms but intruding dry air may act to limit severe hail. That said the drier air will act to enhance downdraft cooling, aiding in strong to marginally severe downburst potential. Convection may linger well into the overnight hours as the vort max aloft pivots across the region. Areas north of the front, mainly southeast GA, will be cooler tonight by a few degrees with lows in the mid to upper 60s while areas to the south will bottom in the low 70s. .SHORT TERM [Thursday Through Friday Night]... Prevailing flow aloft will become northwesterly on Thursday as upper trough shifts eastward off the Atlantic coast. Meanwhile downstairs, the flow will become very light and somewhat variable as another frontal zone stalls and proceeds to wash out over the region. Isolated to scattered storm chances are expected along the decaying front, generally south of I-10 during the afternoon Thursday. Lighter flow will also unlock the Atlantic seabreeze from the coast on Thursday allowing it to penetrate further inland and bring back the return of summery another area isolated to scattered storms along it. Flow will strengthen out of the south to southwest again on Friday as lower ridge develops over the northern Bahamas and a tropical disturbance over the western Gulf. Moisture will advance northward with the flow while cloud cover associated with the tropical low floats in from the southwest. Near surface flow will remain light enough for the east and west coast sea breezes to press inland, thus scattered storms will be possible as the sea breezes converge during the late afternoon and evening amid the diurnally unstable airmass. Best chances will be in the typical seabreeze meeting location - the 301 corridor in northeast FL. Temperatures will warm to slightly above normal through the end of the week, but may be slightly cooler on Friday as cloud cover spreads into the region. .LONG TERM [Saturday Through Wednesday]... Forecast confidence lowers through the weekend/early next week and will depend on the evolution of the aforementioned tropical disturbance and sprawling mid-level ridge across the Atlantic. If the ridge is further south or east, substantial tropical moisture and resultant rainfall is not out of the question. We will be keeping our eye on potential track of the disturbance and/or its remnants and hopefully gain better insight into the local influence over the next couple of days. Expect mostly dry conditions on Saturday as exhaust outflow from the tropical disturbance combats diurnal convective attempts along either sea breeze. Best potential for rainfall associated with the disturbance will be on Sunday. A fetch of tropical moisture, emanating from the Gulf, will reside over the area through much of next week. An upstream trough is also forecast to swing through the Southeast by the middle of next week, which will aid precip chances through next week amid the entrenched tropical airmass. && .AVIATION... [Through 18Z Thursday] West-southwesterly winds prevail today with gusts around 15-20 kts. MVFR ceilings will be possible ahead and with storms. Scattered showers and storms are expected to develop ahead of a frontal boundary over southern Georgia and along the Gulf coast sea breeze this afternoon. Storms will linger into the evening hours as the front pushes southward. Storms should disperse by midnight. Some storms may cause gusty winds and lower visibilities due to heavy downpours. Have TEMPOs in to cover this. && .MARINE... A weak low over the GA coastal waters will develop this evening along a stationary boundary. Locally stronger winds, around 15-20 knots, are possible as this low takes shape tonight and through Thursday morning. Additionally, strong thunderstorms are possible along the boundary and may produce strong winds. Another front will press south into the waters on Thursday, stalling the the FL/GA line. This will yield northeasterly winds to coastal GA waters and continuing southwest to west winds over the FL waters on Thursday. High pressure ridge to the northeast will extend an axis into the waters Friday shifting winds to southeast. Southerly winds may strengthening to 20-25 knots late this weekend as a remnant tropical disturbance lifts from the Gulf and into the Southeast US. Rip Currents: Lack of onshore swell keep Risk at low to moderate over the next several days. && .FIRE WEATHER... Stationary boundary will along FL/GA line will linger through Thursday with transport winds becoming lighter Thursday and Friday as influence of high pressure increases. Sufficient to High dispersion is expected this afternoon with poor dispersion returning tomorrow (Thursday) with the lighter flow through the end of the week. Low afternoon humidities are expected north of the boundary, especially across inland southeast GA. A tropical disturbance is forecast to lift into the southeast this weekend, which will bring tropical moisture into the area. Prolonged periods of heavy rainfall will be possible from Sunday onward through the middle of next week with tropical moisture in place. && .HYDROLOGY... A remnant tropical disturbance lifting into the Southeast US will usher moisture into the region late this weekend. Rich tropical moisture will linger through across the region through next week, prolonging the potential for heavy rainfall. Sensitive basins may need closer monitoring next week. && .PRELIMINARY POINT TEMPS/POPS... AMG 67 94 69 92 70 / 10 0 0 20 0 SSI 74 89 76 89 76 / 30 0 0 10 0 JAX 71 91 72 91 72 / 70 20 10 20 0 SGJ 72 89 73 88 74 / 60 30 10 20 0 GNV 70 89 70 90 70 / 70 30 10 30 0 OCF 72 89 72 91 72 / 40 50 10 30 0 && .JAX WATCHES/WARNINGS/ADVISORIES... FL...None. GA...None. AM...None. &&
PRELIMINARY LOCAL STORM REPORT
National Weather Service Jacksonville FL
421 PM EDT WED JUN 16 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0650 PM TSTM WND GST 4 SE SAINT AUGUSTINE 29.86N 81.26W
06/15/2021 M48.00 MPH AMZ454 FL C-MAN STATION
CMAN SAUF1 REPORTED A PEAK GUST FROM 350 DEGREES AT 48
MPH / 42 KNOTS.
&&Special Weather Statement National Weather Service Jacksonville FL 442 PM EDT Wed Jun 16 2021 FLZ033-133-162130- Coastal St. Johns FL-Inland St. Johns FL- 442 PM EDT Wed Jun 16 2021 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL ST. JOHNS COUNTY UNTIL 530 PM EDT... * At 441 PM EDT, National Weather Service meteorologists were tracking a strong thunderstorm near World Golf Village, or 11 miles west of Saint Augustine, moving east at 10 mph. * Small hail and winds in excess of 45 mph possible with this storm. * Locations impacted include... Saint Augustine, World Golf Village, Vilano Beach, South Ponte Vedra, Guana River State Park and Bakersville. PRECAUTIONARY/PREPAREDNESS ACTIONS... To report severe weather, contact your nearest law enforcement agency. You can also share your report with NWS Jacksonville on Facebook and Twitter. && LAT...LON 2989 8154 2999 8159 3013 8130 2989 8123 TIME...MOT...LOC 2041Z 248DEG 11KT 2995 8149 SHASHY
The Jacksonville radar (KJAX), 62 km away, was scanning. The volume nearest the first event began at 21:17 UTC.
2 lightning, 2 thunderstorm wind, 1 flood. Local standard time, as filed.
A spotter reported the intersection of State Road 16 and International Golf Parkway had about 3-4 inches of water covering it.
A lightning fire caused damage at the Legends Condo complex in the World Golf Village. A portion of the roof had severe fire damage. The cost of damage was unknown, but it was estimated for inclusion in Storm Data. It is likely a gross underestimate of damage.
A tree fell on a powerline just north of St. Augustine.
Numerous trees were blown down onto power lines in the southern portion of St. Augustine. The time of the event was based on radar.
Lighting struck a home in Dinsmore and caused a fire with significant damage and losses. The cost of damage was unknown, but it was estimated for Storm Data. It is likely a gross underestimate.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2021Every state in 2021This day in weather historyWarnings in Florida, June 2021
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: 960250, 960254, 960251, 960253, 960252.