Tornadoes · United States · Florida · 2017

EF1 tornado, Saint Johns County, Florida, June 6, 2017

This EF1 tornado ran 2.2 miles across Saint Johns County on June 6, 2017, touching down at 2:11 PM EDT and reaching 70 yards wide. It killed nobody.

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
June 6, 2017
Touchdown
2:11 PM EDT (18:11 UTC)
Lifted
2:16 PM EDT (18:16 UTC)
On the ground
5 minutes
Path length
2.2 miles (3.6 km)
Path width
70 yards (64 m)
Deaths
0
Injuries
0
County
Saint Johns County
Touchdown point
29.737, -81.312
Lift-off point
29.753, -81.280
Record number
1706061211-01

The damage survey

6 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 95 mph.

  • Complete failure of pool enclousure
  • Numerous trees with trunks snapped

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

The warnings

5 minutes of warning. NWS JAX issued a tornado warning for this county at 18:06 UTC, 5 minutes before the tornado touched down, in force until 18:30 UTC.

Issued (UTC)ExpiredProductOffice
18:00 UTC18:30 UTCSevere Thunderstorm WarningJAX
18:06 UTC18:30 UTCTornado WarningJAX
18:14 UTC20:15 UTCFlood AdvisoryJAX
19:52 UTC00:29 UTCFlood WatchJAX

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 Marginal Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 16:37 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

6.2 hours before the tornado, 92 km from the path. June 6, 2017.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 12:00Z on 2017-06-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 398 joules per kilogram, CIN -12, lifted condensation level 617 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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 2017-06-06The 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 -49 square meters per square second, 0 to 6 km bulk shear 12 knots.1939Sfc1 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
398 J/kg
Mixed-layer CIN
-12 J/kg
Surface CAPE
723 J/kg
Mixed-layer LCL
617 m above ground
0-6 km bulk shear
12 kt
0-1 km bulk shear
17 kt
0-1 km storm-relative helicity
-49 m²/s²
0-3 km storm-relative helicity
-63 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

Jacksonville, FL (KJAX), 00:00Z

5.8 hours after it, 92 km from the path. June 7, 2017.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 00:00Z on 2017-06-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 283 joules per kilogram, CIN -273, lifted condensation level 998 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 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 2017-06-07The 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 38 square meters per square second, 0 to 6 km bulk shear 38 knots.19395878Sfc1 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
283 J/kg
Mixed-layer CIN
-273 J/kg
Surface CAPE
1532 J/kg
Mixed-layer LCL
998 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
4 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
136 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

The surface observations

St Augustine Airpt (SGJ), 24 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
16:15 UTC210° 6 kt1009.1
16:20 UTC210° 7 kt1009.1
16:25 UTC200° 7 kt1008.8
16:30 UTC200° 7 kt1008.8-RA
16:35 UTC200° 6 kt1008.8-RA
16:40 UTC220° 6 kt1008.8
16:45 UTC250° 4 kt1008.5
16:55 UTC220° 5 kt1008.1
16:56 UTC8374 4 kt1008.1
17:00 UTC220° 5 kt1007.8
17:05 UTC250° 5 kt1007.8
17:10 UTC210° 6 kt1007.8
17:15 UTC230° 6 kt1007.8
17:20 UTC230° 5 kt1007.8
17:25 UTC240° 5 kt1007.8
17:30 UTC270° 6 kt1008.1HZ
17:32 UTC82.473.4280° 6 kt1008.1VCTS HZ
17:35 UTC270° 7 kt1008.1HZ
17:40 UTC260° 6 kt1008.1HZ
17:45 UTC290° 5 kt1007.8-RA
17:50 UTC260° 6 kt1007.8RA
17:55 UTC180° 11 kt1008.1+RA BR
17:56 UTC7975170° 11 kt1008.1VCTS +RA BR
18:00 UTC190° 8 kt1007.8RA BR
18:05 UTC200° 6 kt1007.5RA BR
18:07 UTC75.273.4210° 5 kt1007.8TSRA BR
18:10 UTC220° 7 kt1008.1RA BR
18:15 UTC210° 7 kt1008.5+RA BR
18:20 UTC180° 14 kt1008.1+RA BR
18:25 UTC180° 11 kt1007.8RA BR
18:30 UTC190° 9 kt1007.5-RA BR
18:35 UTC230° 7 kt1007.8-RA BR
18:40 UTC270° 8 kt1008.1-RA BR
18:45 UTC250° 7 kt1008.8-RA BR
18:50 UTC250° 7 kt1008.8-RA BR
18:55 UTC260° 11 kt1008.5-RA BR
18:56 UTC7572270° 9 kt1008.5-RA BR
19:00 UTC250° 9 kt1008.8-RA
19:01 UTC73.471.6260° 9 kt1008.8-TSRA
19:05 UTC260° 10 kt1008.8-RA BR
19:08 UTC73.471.6250° 8 kt1008.8-TSRA BR
19:10 UTC240° 6 kt1008.8-RA BR
19:18 UTC73.473.4230° 6 kt1009.1VCTS -RA BR
19:20 UTC210° 6 kt1009.1-RA BR
19:25 UTC240° 4 kt1008.8RA BR
19:30 UTC270° 5 kt1008.8-RA BR
19:35 UTC270° 7 kt1008.5RA BR
19:40 UTC270° 6 kt1008.5RA BR
19:45 UTC250° 5 kt1008.5-RA BR
19:47 UTC73.471.6240° 5 kt1008.5-RA BR
19:50 UTC230° 4 kt1008.5-RA BR
19:55 UTC250° 5 kt1008.5-RA BR
19:56 UTC7371260° 5 kt1008.5-RA BR
20:00 UTC260° 5 kt1008.5-RA
20:03 UTC73.471.6280° 5 kt1008.5-RA
20:05 UTC270° 5 kt1008.5-RA BR
20:10 UTC260° 7 kt1008.1BR

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Jacksonville radar (KJAX), 91 km away, was scanning. The volume nearest the touchdown began at 18:10 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
18:10 UTCTORNADO 11 Se Dupont CenterSt. Johns, FLDAMAGE SURVEY ONGOING. PRELIMINARY RESULTS OF WEAK EF-1 DAMAGE.
18:10 UTCTORNADO1 Se Dupont CenterSt. Johns, FLTREES DOWN ON US 1 JUST SOUTH OF SR 206 SOUTH OF THE FLORIDA FOREST SERVICE TOWER, WITH REPORTS OF TREES BLOCKING ROADWAY.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2017 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

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.