Tornadoes · United States · Florida · 2019

EF0 tornado, Summerland Key, Florida, August 4, 2019

This EF0 tornado ran 0.1 miles across Monroe County on August 4, 2019, touching down at 7:20 PM EDT and reaching 20 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
August 4, 2019
Touchdown
7:20 PM EDT (23:20 UTC)
Lifted
7:21 PM EDT (23:21 UTC)
On the ground
1 minutes
Path length
0.1 miles (0.1 km)
Path width
20 yards (18 m)
Deaths
0
Injuries
0
County
Monroe County
Touchdown point
24.648, -81.481
Lift-off point
24.647, -81.480
Record number
1908041720-01

What the Weather Service recorded

A waterspout developed in Cudjoe Bay in association with a convective cloud line over the Lower Florida Keys. The waterspout moved east-southeast onshore the south end of Cudjoe Key and dissipated immediately. It did not produce any significant damage nor injuries.

A waterspout over Cudjoe Bay moved east-southeast and onshore as a tornado over the south end of Cudjoe Key. Maximum wind speeds were estimated at 50 to 60 mph with only a few palm fronds downed and a small piece of vinyl siding from one waterfront home. The tornado dissipated immediately over a narrow peninsula before reaching the oceanside shoreline.

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.

Issued (UTC)ExpiredProductOffice
15:00 UTC23:00 UTCCoastal Flood StatementKEY

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 20:02 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.

Key West, FL (KEYW), 12:00Z

11.3 hours before the tornado, 26 km from the path. August 4, 2019.

Skew-T log-pSkew-T log-p diagram, Key West, FL at 12:00Z on 2019-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1819 joules per kilogram, CIN -5, lifted condensation level 842 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, Key West, FL at 12:00Z on 2019-08-04The 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 3 square meters per square second, 0 to 6 km bulk shear 6 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
1819 J/kg
Mixed-layer CIN
-5 J/kg
Surface CAPE
2805 J/kg
Mixed-layer LCL
842 m above ground
0-6 km bulk shear
6 kt
0-1 km bulk shear
6 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
-8 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

Key West, FL (KEYW), 00:00Z

0.7 hours after it, 26 km from the path. August 5, 2019.

Skew-T log-pSkew-T log-p diagram, Key West, FL at 00:00Z on 2019-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3003 joules per kilogram, CIN -49, lifted condensation level 986 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, Key West, FL at 00:00Z on 2019-08-05The 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 11 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
3003 J/kg
Mixed-layer CIN
-49 J/kg
Surface CAPE
550 J/kg
Mixed-layer LCL
986 m above ground
0-6 km bulk shear
12 kt
0-1 km bulk shear
3 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

The surface observations

Key West Nas (NQX), 23 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:53 UTC8776300° 13 kt171015.9-RA
22:53 UTC8673300° 8 kt1015.6
23:53 UTC8575300° 3 kt1016.3
00:53 UTC8575330° 3 kt1016.9

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

The radar

The Key West radar (KBYX), 23 km away, was scanning. The volume nearest the touchdown began at 23:23 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
22:20 UTCTORNADOCudjoe KeyLower Keys In Monr, FLA WATERSPOUT OVER CUDJOE BAY MOVED EAST-SOUTHEAST AND ONSHORE NEAR THE SOUTHEAST TIP OF CUDJOE KEY BRIEFLY AS A TORNADO BEFORE DISSIPATING. THIS IS CONFIRMED BY VIDEO. NO DAMAGE OR INJURIES ARE REPORTED.

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

This ground now

The live radar over the trackEvery 2019 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.