Tornadoes · United States · Florida · 2024
EF1 tornado, Saint Johns County, Florida, April 11, 2024
This EF1 tornado ran 6.7 miles across Saint Johns County on April 11, 2024, touching down at 11:33 AM EDT and reaching 310 yards wide. It killed nobody and injured 1.
The rating scale
Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mphthis tornado
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.
The record
- Rating
- EF1
- Date
- April 11, 2024
- Touchdown
- 11:33 AM EDT (15:33 UTC)
- Lifted
- 11:45 AM EDT (15:45 UTC)
- On the ground
- 12 minutes
- Path length
- 6.7 miles (10.8 km)
- Path width
- 310 yards (283 m)
- Deaths
- 0
- Injuries
- 1
- County
- Saint Johns County
- Touchdown point
- 29.885, -81.563
- Lift-off point
- 29.948, -81.478
- Record number
- 2404110933-01
The damage survey
37 damage points were recorded along this path by NWS JAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF1. The highest wind the damage implies is 100 mph.
- Fences down, some damage to Soffit, roof tiles list < 20%
- large section of roof tiles damage and torn from residence.
- Several fences toppled and destroyed
- fence down, withown blown out. Soffit damage
Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.
The warnings
4 minutes of warning. NWS JAX issued a tornado warning for this county at 15:29 UTC, 4 minutes before the tornado touched down, in force until 15:45 UTC.
The county was under a tornado watch, issued at 11:33 UTC and running to 17:50 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 06:00 UTC | 00:00 UTC | Wind Advisory | JAX |
| 11:33 UTC | 17:50 UTC | Tornado Watch | JAX |
| 15:05 UTC | 15:30 UTC | Severe Thunderstorm Warning | JAX |
| 15:27 UTC | 15:45 UTC | Severe Thunderstorm Warning | JAX |
| 15:29 UTC | 15:45 UTC | Tornado Warning | JAX |
| 15:41 UTC | 16:00 UTC | Tornado Warning | JAX |
Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.
The forecast that day
The Storm Prediction Center had this point in a Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 12:52 UTC.
SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.
The air that afternoon
The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.
Jacksonville, FL (KJAX), 12:00Z
3.6 hours before the tornado, 67 km from the path. April 11, 2024.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -92462 J/kg
- Surface CAPE
- 11 J/kg
- Mixed-layer LCL
- 847 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 178 m²/s²
- 0-3 km storm-relative helicity
- 184 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.1 K/km
Jacksonville, FL (KJAX), 00:00Z
8.4 hours after it, 67 km from the path. April 12, 2024.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -87469 J/kg
- Surface CAPE
- 3 J/kg
- Mixed-layer LCL
- 1473 m above ground
- 0-6 km bulk shear
- 73 kt
- 0-1 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 63 m²/s²
- 0-3 km storm-relative helicity
- 193 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.4 K/km
The surface observations
St Augustine Airpt (SGJ), 18 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 13:35 UTC | 180° 15 kt | 1007.5 | ||||
| 13:40 UTC | 180° 18 kt | 1007.8 | ||||
| 13:45 UTC | 190° 14 kt | 21 | 1007.8 | |||
| 13:50 UTC | 170° 14 kt | 21 | 1007.8 | |||
| 13:55 UTC | 180° 14 kt | 1007.8 | ||||
| 13:56 UTC | 76 | 68 | 180° 13 kt | 21 | 1007.8 | |
| 14:00 UTC | 180° 14 kt | 1007.5 | ||||
| 14:03 UTC | 75.2 | 68 | 170° 14 kt | 20 | 1007.5 | |
| 14:05 UTC | 180° 11 kt | 1007.5 | ||||
| 14:10 UTC | 170° 11 kt | 1007.5 | ||||
| 14:15 UTC | 170° 16 kt | 1007.5 | ||||
| 14:20 UTC | 160° 13 kt | 1007.5 | ||||
| 14:25 UTC | 180° 13 kt | 18 | 1007.1 | |||
| 14:30 UTC | 170° 17 kt | 1007.1 | -RA | |||
| 14:35 UTC | 170° 17 kt | 22 | 1006.8 | -RA | ||
| 14:40 UTC | 180° 18 kt | 24 | 1006.4 | -RA | ||
| 14:45 UTC | 180° 14 kt | 1006.4 | -RA | |||
| 14:50 UTC | 180° 15 kt | 1006.4 | -RA | |||
| 14:55 UTC | 180° 16 kt | 24 | 1006.8 | -RA | ||
| 14:56 UTC | 75 | 70 | 190° 18 kt | 25 | 1006.8 | VCTS -RA |
| 15:00 UTC | 190° 15 kt | 1006.8 | -RA | |||
| 15:05 UTC | 75.2 | 69.8 | 190° 16 kt | 24 | 1007.1 | -RA |
| 15:05 UTC | 1007.1 | -RA | ||||
| 15:10 UTC | 190° 15 kt | 21 | 1007.5 | -RA | ||
| 15:13 UTC | 75.2 | 69.8 | 200° 13 kt | 23 | 1007.8 | -RA |
| 15:15 UTC | 190° 11 kt | 18 | 1007.8 | -RA | ||
| 15:20 UTC | 200° 14 kt | 1007.8 | RA | |||
| 15:23 UTC | 75.2 | 71.6 | 200° 12 kt | 18 | 1007.8 | +TSRA BR |
| 15:25 UTC | 200° 13 kt | 1007.8 | +RA BR | |||
| 15:27 UTC | 73.4 | 71.6 | 190° 22 kt | 40 | 1008.1 | +TSRA BR |
| 15:30 UTC | 73.4 | 71.6 | 200° 15 kt | 40 | 1007.1 | +TSRA BR |
| 15:30 UTC | 190° 15 kt | 1007.1 | +RA BR | |||
| 15:35 UTC | 170° 8 kt | 1007.1 | -RA BR | |||
| 15:40 UTC | 190° 8 kt | 1007.1 | -RA BR | |||
| 15:41 UTC | 73.4 | 71.6 | 190° 10 kt | 15 | 1007.1 | -TSRA BR |
| 15:45 UTC | 150° 10 kt | 1006.8 | -RA BR | |||
| 15:50 UTC | 170° 15 kt | 22 | 1006.4 | BR | ||
| 15:55 UTC | 22 | 1006.4 | -RA BR | |||
| 15:56 UTC | 75 | 71 | 180° 17 kt | 27 | 1006.4 | -RA BR |
| 16:00 UTC | 200° 16 kt | 1006.8 | -RA | |||
| 16:03 UTC | 75.2 | 71.6 | 220° 11 kt | 26 | 1007.1 | -RA |
| 16:05 UTC | 220° 11 kt | 1007.1 | -RA BR | |||
| 16:10 UTC | 250° 5 kt | 1007.5 | -RA BR | |||
| 16:15 UTC | 220° 4 kt | 1007.5 | -RA BR | |||
| 16:20 UTC | 210° 8 kt | 1007.1 | -RA BR | |||
| 16:25 UTC | 210° 5 kt | 1007.5 | -RA BR | |||
| 16:30 UTC | 210° 7 kt | 1007.1 | -RA BR | |||
| 16:35 UTC | 180° 7 kt | 1007.1 | -RA BR | |||
| 16:40 UTC | 200° 8 kt | 1007.1 | -RA BR | |||
| 16:45 UTC | 200° 7 kt | 1007.1 | -RA BR | |||
| 16:48 UTC | 75.2 | 71.6 | 210° 7 kt | 1006.8 | VCTS -RA BR | |
| 16:50 UTC | 220° 5 kt | 1007.1 | RA BR | |||
| 16:55 UTC | 250° 5 kt | 1006.8 | -RA BR | |||
| 16:56 UTC | 74 | 72 | 260° 6 kt | 1007.1 | VCTS -RA BR | |
| 17:00 UTC | 270° 11 kt | 1007.5 | -RA BR | |||
| 17:05 UTC | 230° 9 kt | 1007.1 | +RA BR | |||
| 17:10 UTC | 230° 5 kt | 1007.5 | -RA BR | |||
| 17:15 UTC | 220° 7 kt | 1007.1 | -RA BR | |||
| 17:19 UTC | 73.4 | 71.6 | 210° 8 kt | 1007.1 | -RA BR | |
| 17:20 UTC | 220° 7 kt | 1007.1 | -RA BR | |||
| 17:25 UTC | 220° 8 kt | 1007.5 | +RA BR | |||
| 17:27 UTC | 73.4 | 71.6 | 240° 8 kt | 1007.5 | +RA BR | |
| 17:30 UTC | 260° 5 kt | 1007.1 | RA BR |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Jacksonville radar (KJAX), 66 km away, was scanning. The volume nearest the touchdown began at 15:34 UTC.
Open the radar archive at this moment, over the track
Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 12:53 UTC | NON-TSTM WND GST 43 | 4 Ne Orange Park | Duval, FL | AWOS station KNIP Jacksonville Nas ahead of approaching thunderstorms. |
| 13:12 UTC | NON-TSTM WND GST 44 | Mayport | Duval, FL | AWOS station KNRB Mayport Naval Station gusted ahead of thunderstorms. |
| 13:19 UTC | NON-TSTM WND GST 45 | 4 Ne Orange Park | Duval, FL | AWOS station KNIP Jacksonville Nas gusted ahead of thunderstorms. |
| 13:23 UTC | NON-TSTM WND GST 43 | 4 Ssw Fort Caroline | Duval, FL | ASOS station KCRG Jacksonvil Craig gusted ahead of thunderstorms. |
| 13:30 UTC | NON-TSTM WND GST 49 | 2 Wnw Mayport | Amz452, FL | Mesonet station 1483W Fswn Jfrd Station 40 gusted ahead of the thunderstorms. |
| 13:42 UTC | NON-TSTM WND GST 40 | 2 N Mayport | Amz452, FL | Mesonet station XHUP Huguenot Park gusted ahead of the thunderstorms. |
| 13:46 UTC | NON-TSTM WND GST 41 | 1 Ene Fort Caroline | Duval, FL | Mesonet station XJAK Jacksonville gusted ahead of thunderstorms. |
| 15:27 UTC | TSTM WND GST 46 | 2 Nnw Vilano Beach | St. Johns, FL | AWOS station KSGJ St Augustine measured a gust to 46 mph. |
| 15:37 UTC | TORNADO | 3 Nw Bakersville | St. Johns, FL | Visual confirmation of tornado in the World Golf Village in the Trailmark subdivision via media and social media. Excellent radar indication of tornado NWS Survey Team enroute for storm survey to determine path, intensit |
| 15:37 UTC | TORNADO | Trailmark And Samara La | St. Johns, FL | *** 1 INJ *** NWS Damage Survey results concluded that began along County Road 13 and extended across portions of the Trailmark and Samara Lakes neighborhoods in western St Johns County. The tornado was estimated at an E |
| 16:40 UTC | TSTM WND DMG | 1 Sse Crescent City | Putnam, FL | Corrects previous tstm wnd dmg report from 1 SSE Crescent City. Delayed report of 2 trees down in Crescent City on Route 17. Time estimated by radar. |
| 16:40 UTC | TSTM WND DMG | 2 Sse Crescent City | Putnam, FL | Branch fell on a car just south of Junction road and east of US 17. Time estimated by RADAR. |
| 16:55 UTC | TSTM WND GST 55 | 6 Sw Espanola | Flagler, FL | Trained Weather Spotter in Flagler County measured wind speed at the cross section of CR90 and CR305. |
| 17:05 UTC | TSTM WND DMG | West Palm Coast | Flagler, FL | Delayed report. Emergency management reported two trees down. One on Freemont Turn and another on Frontier Drive. Time estimated by radar. |
| 17:13 UTC | TSTM WND GST 45 | 2 E Palm Coast | Amz454, FL | Report by county Emergency Management. Wind measurement taken on Hammock Dunes Bridge. |
| 17:40 UTC | TSTM WND DMG | 1 Sse Crescent City | Putnam, FL | Delayed report of 2 trees down in Crescent City on Route 17. Time estimated by radar. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2024 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are
The other tornadoes of April 11, 2024
3 more were confirmed in the United States that day.
What this means
Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.
Sources
NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.