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.

  1. EF065 to 85 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. EF186 to 110 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. 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.

  4. 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.

  5. EF4166 to 200 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. 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.

  7. 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)ExpiredProductOffice
06:00 UTC00:00 UTCWind AdvisoryJAX
11:33 UTC17:50 UTCTornado WatchJAX
15:05 UTC15:30 UTCSevere Thunderstorm WarningJAX
15:27 UTC15:45 UTCSevere Thunderstorm WarningJAX
15:29 UTC15:45 UTCTornado WarningJAX
15:41 UTC16:00 UTCTornado WarningJAX

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.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 12:00Z on 2024-04-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -92462, lifted condensation level 847 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Jacksonville, FL at 12:00Z on 2024-04-11The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 178 square meters per square second, 0 to 6 km bulk shear 35 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
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

Open this sounding in Storm Lab

Jacksonville, FL (KJAX), 00:00Z

8.4 hours after it, 67 km from the path. April 12, 2024.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 00:00Z on 2024-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -87469, lifted condensation level 1473 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Jacksonville, FL at 00:00Z on 2024-04-12The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 63 square meters per square second, 0 to 6 km bulk shear 73 knots.1939587897117Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
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

Open this sounding in Storm Lab

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)WindGust (kt)Pressure (mb)Weather
13:35 UTC180° 15 kt1007.5
13:40 UTC180° 18 kt1007.8
13:45 UTC190° 14 kt211007.8
13:50 UTC170° 14 kt211007.8
13:55 UTC180° 14 kt1007.8
13:56 UTC7668180° 13 kt211007.8
14:00 UTC180° 14 kt1007.5
14:03 UTC75.268170° 14 kt201007.5
14:05 UTC180° 11 kt1007.5
14:10 UTC170° 11 kt1007.5
14:15 UTC170° 16 kt1007.5
14:20 UTC160° 13 kt1007.5
14:25 UTC180° 13 kt181007.1
14:30 UTC170° 17 kt1007.1-RA
14:35 UTC170° 17 kt221006.8-RA
14:40 UTC180° 18 kt241006.4-RA
14:45 UTC180° 14 kt1006.4-RA
14:50 UTC180° 15 kt1006.4-RA
14:55 UTC180° 16 kt241006.8-RA
14:56 UTC7570190° 18 kt251006.8VCTS -RA
15:00 UTC190° 15 kt1006.8-RA
15:05 UTC75.269.8190° 16 kt241007.1-RA
15:05 UTC 1007.1-RA
15:10 UTC190° 15 kt211007.5-RA
15:13 UTC75.269.8200° 13 kt231007.8-RA
15:15 UTC190° 11 kt181007.8-RA
15:20 UTC200° 14 kt1007.8RA
15:23 UTC75.271.6200° 12 kt181007.8+TSRA BR
15:25 UTC200° 13 kt1007.8+RA BR
15:27 UTC73.471.6190° 22 kt401008.1+TSRA BR
15:30 UTC73.471.6200° 15 kt401007.1+TSRA BR
15:30 UTC190° 15 kt1007.1+RA BR
15:35 UTC170° 8 kt1007.1-RA BR
15:40 UTC190° 8 kt1007.1-RA BR
15:41 UTC73.471.6190° 10 kt151007.1-TSRA BR
15:45 UTC150° 10 kt1006.8-RA BR
15:50 UTC170° 15 kt221006.4BR
15:55 UTC 221006.4-RA BR
15:56 UTC7571180° 17 kt271006.4-RA BR
16:00 UTC200° 16 kt1006.8-RA
16:03 UTC75.271.6220° 11 kt261007.1-RA
16:05 UTC220° 11 kt1007.1-RA BR
16:10 UTC250° 5 kt1007.5-RA BR
16:15 UTC220° 4 kt1007.5-RA BR
16:20 UTC210° 8 kt1007.1-RA BR
16:25 UTC210° 5 kt1007.5-RA BR
16:30 UTC210° 7 kt1007.1-RA BR
16:35 UTC180° 7 kt1007.1-RA BR
16:40 UTC200° 8 kt1007.1-RA BR
16:45 UTC200° 7 kt1007.1-RA BR
16:48 UTC75.271.6210° 7 kt1006.8VCTS -RA BR
16:50 UTC220° 5 kt1007.1RA BR
16:55 UTC250° 5 kt1006.8-RA BR
16:56 UTC7472260° 6 kt1007.1VCTS -RA BR
17:00 UTC270° 11 kt1007.5-RA BR
17:05 UTC230° 9 kt1007.1+RA BR
17:10 UTC230° 5 kt1007.5-RA BR
17:15 UTC220° 7 kt1007.1-RA BR
17:19 UTC73.471.6210° 8 kt1007.1-RA BR
17:20 UTC220° 7 kt1007.1-RA BR
17:25 UTC220° 8 kt1007.5+RA BR
17:27 UTC73.471.6240° 8 kt1007.5+RA BR
17:30 UTC260° 5 kt1007.1RA 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)ReportWhereCountyRemark
12:53 UTCNON-TSTM WND GST 434 Ne Orange ParkDuval, FLAWOS station KNIP Jacksonville Nas ahead of approaching thunderstorms.
13:12 UTCNON-TSTM WND GST 44MayportDuval, FLAWOS station KNRB Mayport Naval Station gusted ahead of thunderstorms.
13:19 UTCNON-TSTM WND GST 454 Ne Orange ParkDuval, FLAWOS station KNIP Jacksonville Nas gusted ahead of thunderstorms.
13:23 UTCNON-TSTM WND GST 434 Ssw Fort CarolineDuval, FLASOS station KCRG Jacksonvil Craig gusted ahead of thunderstorms.
13:30 UTCNON-TSTM WND GST 492 Wnw MayportAmz452, FLMesonet station 1483W Fswn Jfrd Station 40 gusted ahead of the thunderstorms.
13:42 UTCNON-TSTM WND GST 402 N MayportAmz452, FLMesonet station XHUP Huguenot Park gusted ahead of the thunderstorms.
13:46 UTCNON-TSTM WND GST 411 Ene Fort CarolineDuval, FLMesonet station XJAK Jacksonville gusted ahead of thunderstorms.
15:27 UTCTSTM WND GST 462 Nnw Vilano BeachSt. Johns, FLAWOS station KSGJ St Augustine measured a gust to 46 mph.
15:37 UTCTORNADO3 Nw BakersvilleSt. Johns, FLVisual 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 UTCTORNADOTrailmark And Samara LaSt. 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 UTCTSTM WND DMG1 Sse Crescent CityPutnam, FLCorrects 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 UTCTSTM WND DMG2 Sse Crescent CityPutnam, FLBranch fell on a car just south of Junction road and east of US 17. Time estimated by RADAR.
16:55 UTCTSTM WND GST 556 Sw EspanolaFlagler, FLTrained Weather Spotter in Flagler County measured wind speed at the cross section of CR90 and CR305.
17:05 UTCTSTM WND DMGWest Palm CoastFlagler, FLDelayed report. Emergency management reported two trees down. One on Freemont Turn and another on Frontier Drive. Time estimated by radar.
17:13 UTCTSTM WND GST 452 E Palm CoastAmz454, FLReport by county Emergency Management. Wind measurement taken on Hammock Dunes Bridge.
17:40 UTCTSTM WND DMG1 Sse Crescent CityPutnam, FLDelayed 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.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
April 116:43 PM EDTEF1Wilkes, NC6.0150$250,000
April 117:52 PM EDTEF1Rowan, NC1.340$75,000
April 119:27 PM EDTEF1Pittsylvania, VA0.9250$15,000

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.