Tornadoes · United States · Florida · 2020

EF0 tornado, Saint Johns County, Florida, March 31, 2020

This EF0 tornado ran 0.4 miles across Saint Johns County on March 31, 2020, touching down at 7:29 PM EDT and reaching 704 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 mphthis tornado

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

  2. EF186 to 110 mph

    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
EF0
Date
March 31, 2020
Touchdown
7:29 PM EDT (23:29 UTC)
Lifted
7:30 PM EDT (23:30 UTC)
On the ground
1 minutes
Path length
0.4 miles (0.6 km)
Path width
704 yards (644 m)
Deaths
0
Injuries
0
County
Saint Johns County
Touchdown point
30.141, -81.356
Lift-off point
30.142, -81.350
Record number
2003311729-01

The damage survey

18 damage points were recorded along this path by NWS JAX, in the Damage Assessment Toolkit the survey teams carry. The strongest indicator was rated EF0. The highest wind the damage implies is 80 mph.

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

The warnings

0 minutes of warning. NWS JAX issued a tornado warning for this county at 23:29 UTC, 0 minutes before the tornado touched down, in force until 23:33 UTC.

The county was under a tornado watch, issued at 22:20 UTC and running to 23:54 UTC.

Issued (UTC)ExpiredProductOffice
22:20 UTC23:54 UTCTornado WatchJAX
22:28 UTC23:15 UTCSevere Thunderstorm WarningJAX
23:07 UTC23:16 UTCTornado WarningJAX
23:29 UTC23:33 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 Marginal Risk. The outlook in force was issued at 19:11 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

11.5 hours before the tornado, 52 km from the path. March 31, 2020.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 12:00Z on 2020-03-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 77 joules per kilogram, CIN -63, lifted condensation level 577 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2020-03-31The 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 122 square meters per square second, 0 to 6 km bulk shear 52 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
77 J/kg
Mixed-layer CIN
-63 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
577 m above ground
0-6 km bulk shear
52 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
122 m²/s²
0-3 km storm-relative helicity
184 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1
0-3 km lapse rate
3.6 K/km

Open this sounding in Storm Lab

Jacksonville, FL (KJAX), 00:00Z

0.5 hours after it, 52 km from the path. April 1, 2020.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 00:00Z on 2020-04-01Temperature 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 -83076, lifted condensation level 1520 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°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 2020-04-01The 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 97 square meters per square second, 0 to 6 km bulk shear 68 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
-83076 J/kg
Surface CAPE
121 J/kg
Mixed-layer LCL
1520 m above ground
0-6 km bulk shear
68 kt
0-1 km bulk shear
34 kt
0-1 km storm-relative helicity
97 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

The radar

The Jacksonville radar (KJAX), 51 km away, was scanning. The volume nearest the touchdown began at 23:29 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
21:05 UTCNON-TSTM WND GST 462 Wsw ArlingtonDuval, FLA WEATHERSTEM MESONET AT TIAA BANK FIELD MEASURED A PEAK WIND GUST OF 46 MPH.
21:50 UTCNON-TSTM WND GST 412 N MayportAmz452, FLWEATHERFLOW SITE AT HUGUENOT PARK MEASURED A WIND GUST OF 41 MPH.
22:50 UTCTSTM WND DMG4 Wnw LakesideClay, FLFENCE DAMAGED AND GARAGE DOOR BLOWN INWARD IN OAKLEAF AREA NEAR MIDDLEBURG. TIME ESTIMATED BY RADAR.
22:50 UTCTSTM WND DMG4 Wnw LakesideClay, FLFENCE DAMAGED AND GARAGE DOOR BLOWN INWARD IN OAKLEAF AREA NEAR MIDDLEBURG. TIME ESTIMATED BY RADAR.
23:00 UTCTSTM WND DMG5 Wsw Fruit CoveClay, FLTREE FELL ON A HOUSE CAUSING MAJOR DAMAGE ON FLEMING ISLAND. TIME ESTIMATED BY RADAR.
23:00 UTCTSTM WND DMG5 Wsw Fruit CoveClay, FLTREE FELL ON A HOUSE CAUSING MAJOR DAMAGE ON FLEMING ISLAND. TIME ESTIMATED BY RADAR.
23:05 UTCTSTM WND DMG3 Nne Fruit CoveDuval, FLTREE ACROSS SOUTH BURNING TREE LANE IN MANDARIN. POWER OUTAGES REPORTED.
23:05 UTCTSTM WND DMG3 Nne Fruit CoveDuval, FLTREE ACROSS SOUTH BURNING TREE LANE IN MANDARIN. POWER OUTAGES REPORTED.
23:10 UTCTSTM WND DMG4 Nw Fruit CoveDuval, FLLARGE TREE DOWN IN YARD ON MANDARIN ROAD.
23:10 UTCTSTM WND DMG4 Nw Fruit CoveDuval, FLLARGE TREE DOWN IN YARD ON MANDARIN ROAD.
23:29 UTCTORNADO4 Nnw Guana River StateSt. Johns, FLNWS DAMAGE ASSESSMENT FOUND AN EF-0 TORNADO WITH 80 MPH WINDS BRIEFLY TOUCHED DOWN IN PONTE VEDRA BEACH NEAR GUANA RIVER STATE PARK. THIS TORNADO CAUSED TREE DAMAGE AND SOME DAMAGE TO NEARBY HOUSES INCLUDING ABROKEN WIND
23:29 UTCTORNADO4 Nnw Guana River StateSt. Johns, FLNWS DAMAGE ASSESSMENT FOUND AN EF-0 TORNADO WITH 80 MPH WINDS BRIEFLY TOUCHED DOWN IN PONTE VEDRA BEACH NEAR GUANA RIVER STATE PARK. THIS TORNADO CAUSED TREE DAMAGE AND SOME DAMAGE TO NEARBY HOUSES INCLUDING ABROKEN WIND

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

This ground now

The live radar over the trackEvery 2020 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

The other tornadoes of March 31, 2020

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
March 319:30 AM CDTEF1George, MS8.250
March 3110:23 AM CDTEF0Montgomery, AL3.3190
March 3110:33 AM CDTEF0Pike, AL0.180
March 3110:34 AM CDTEF0Pike, AL1.680
March 3110:51 AM CDTEF0Pike, AL0.8180
March 3111:34 AM CDTEF2Barbour, AL to GA30.03501$50,000
March 3112:55 PM CDTEF0Walton, FL0.225$2,000
March 314:10 PM EDTEF1Jefferson, FL9.2150$2,000
March 314:17 PM EDTEF1Madison, FL11.7100
March 314:33 PM EDTEF0Madison, FL0.150$50,000
March 315:26 PM EDTEF0Suwannee, FL0.8704
March 312:30 PM PDTEF0Benton, WA0.120

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.