Tornadoes · United States · Florida · 2017

EF0 tornado, Cardwell, Florida, May 2, 2017

This EF0 tornado ran 0.3 miles across Palm Beach County on May 2, 2017, touching down at 5:30 PM EDT and reaching 25 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
May 2, 2017
Touchdown
5:30 PM EDT (21:30 UTC)
Lifted
5:35 PM EDT (21:35 UTC)
On the ground
5 minutes
Path length
0.3 miles (0.4 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Palm Beach County
Touchdown point
26.740, -80.610
Lift-off point
26.740, -80.610
Record number
1705021530-01

What the Weather Service recorded

A mid to upper level low pressure system moved over South Florida. A cold front was also moving down the state and stalling out across the Lake Okeechobee region. Afternoon thunderstorms developed along the front and sea breezes. One of these thunderstorms became severe and produced a brief tornado.

Broadcast media relayed a video of a brief tornado touchdown between Belle Glade and Pahokee. The tornado remained over an open field with no damage reported and therefore no official rating given.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down. One was issued for the county at another hour that day.

Issued (UTC)ExpiredProductOffice
21:38 UTC22:00 UTCTornado WarningMFL
21:40 UTC22:15 UTCSevere Thunderstorm WarningMFL
21:57 UTC22:30 UTCTornado WarningMFL

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 General Thunderstorms Risk. The outlook in force was issued at 19:42 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.

Miami, FL (KMFL), 12:00Z

9.5 hours before the tornado, 107 km from the path. May 2, 2017.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 12:00Z on 2017-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 506 joules per kilogram, CIN -6, lifted condensation level 786 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, Miami, FL at 12:00Z on 2017-05-02The 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 -18 square meters per square second, 0 to 6 km bulk shear 11 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
506 J/kg
Mixed-layer CIN
-6 J/kg
Surface CAPE
968 J/kg
Mixed-layer LCL
786 m above ground
0-6 km bulk shear
11 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.1 K/km

Open this sounding in Storm Lab

Miami, FL (KMFL), 00:00Z

2.5 hours after it, 107 km from the path. May 3, 2017.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 00:00Z on 2017-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 675 joules per kilogram, CIN -13, lifted condensation level 828 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, Miami, FL at 00:00Z on 2017-05-03The 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 43 square meters per square second, 0 to 6 km bulk shear 17 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
675 J/kg
Mixed-layer CIN
-13 J/kg
Surface CAPE
1052 J/kg
Mixed-layer LCL
828 m above ground
0-6 km bulk shear
17 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
43 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

The surface observations

West Palm Beach (DJT), 51 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:30 UTC140° 12 kt1015.6-RA
19:35 UTC 1015.6-RA
19:40 UTC140° 13 kt1015.6-RA
19:45 UTC150° 15 kt201015.6-RA
19:50 UTC 1015.6-RA
19:53 UTC8173130° 15 kt1015.6-RA
19:55 UTC 1015.6-RA
20:00 UTC140° 14 kt191015.6
20:05 UTC 1015.2
20:10 UTC 1015.2
20:15 UTC 1015.2
20:20 UTC 1014.9
20:25 UTC 1014.9
20:30 UTC150° 15 kt1014.9
20:35 UTC 1014.9
20:40 UTC160° 15 kt1014.9
20:45 UTC 1015.2
20:50 UTC130° 16 kt1015.2
20:53 UTC8269130° 19 kt1015.2
20:55 UTC 1014.9
21:00 UTC 1014.9
21:05 UTC 1015.2
21:10 UTC 1015.2
21:15 UTC 1015.2
21:20 UTC 1015.2
21:25 UTC 1014.9
21:30 UTC140° 12 kt1014.9
21:35 UTC 1014.9
21:40 UTC 1014.6
21:45 UTC 1014.6
21:50 UTC 1015.2
21:53 UTC7970140° 14 kt211015.2
21:55 UTC
22:00 UTC140° 12 kt1015.2
22:01 UTC7970140° 12 kt1015.2TS
22:05 UTC140° 13 kt1015.6
22:10 UTC 1015.9
22:15 UTC130° 10 kt1015.9
22:20 UTC140° 11 kt1015.9
22:25 UTC130° 12 kt1015.6
22:30 UTC140° 13 kt1015.2
22:35 UTC150° 11 kt1015.9
22:40 UTC130° 11 kt1015.9
22:45 UTC130° 10 kt1015.9
22:50 UTC130° 9 kt1016.3
22:53 UTC7970150° 7 kt1016.3TS
22:55 UTC140° 8 kt
23:00 UTC150° 9 kt
23:05 UTC140° 7 kt
23:10 UTC150° 6 kt1016.6
23:15 UTC150° 6 kt
23:20 UTC140° 5 kt
23:25 UTC220° 6 kt-RA

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

The radar

The Miami radar (KAMX), 127 km away, was scanning. The volume nearest the touchdown began at 21:30 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
21:00 UTCMARINE TSTM WIND 4212 E LakeportAmz610, FLA MARINE THUNDERSTORM WIND GUST OF 42MPH...36 KNOTS...WAS REPORTED BY THE SFWMD MESONET SITE L005 LOCATED OVER THE WESTERN HALF OF LAKE OKEECHOBEE AT 500PM EDT.
21:15 UTCMARINE TSTM WIND 397 W PahokeeAmz610, FLA MARINE THUNDERSTORM WIND GUST OF 39 MPH...34 KNOTS WAS REPORTED BY THE SFWMD MESONET SITE L006 LOCATED OVER THE SOUTHERN END OF LAKE OKEECHOBEE AT 515PM EDT.
21:15 UTCMARINE TSTM WIND 4510 Nw PahokeeAmz610, FLA MARINE THUNDERSTORM WIND GUST OF 45 MPH...39 KNOTS WAS REPORTED BY THE SFWMD MESONET SITE LZ40 LOCATED OVER THE CENTER OF LAKE OKEECHOBEE AT 515PM EDT.
21:30 UTCTORNADO5 Ne Belle GladePalm Beach, FLA MEMBER OF THE BROADCAST MEDIA RELAYED A VIDEO OF A TORNADO SEEN FROM US 441 BETWEEN BELLE GLADE AND PAHOKEE. LOCATION AND TIME IS ESTIMATED BASED ON RADAR DATA. THERE WERE NO REPORTS OF DAMAGE AS THIS TORNADO OCCURED O

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.