Tornadoes · United States · Florida · 2017

EF0 tornado, Corkscrew, Florida, November 22, 2017

This EF0 tornado ran 0.3 miles across Collier County on November 22, 2017, touching down at 4:40 PM EST 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
November 22, 2017
Touchdown
4:40 PM EST (21:40 UTC)
Path length
0.3 miles (0.4 km)
Path width
25 yards (23 m)
Deaths
0
Injuries
0
County
Collier County
Touchdown point
26.420, -81.530
Lift-off point
26.420, -81.530
Record number
1711221540-01

What the Weather Service recorded

A frontal boundary across the region and a few showers across South Florida. A brief tornado/ land spout occurred in rural portions of Collier County.

Collier County Sheriff Office reported via a police helicopter a tornado in the Corkscrew area in Collier County. The tornado was brief and stayed in an open field with no damage reported.

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.

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 19:30 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

9.7 hours before the tornado, 141 km from the path. November 22, 2017.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 12:00Z on 2017-11-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 286 joules per kilogram, CIN -66, lifted condensation level 1037 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, Miami, FL at 12:00Z on 2017-11-22The 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 21 square meters per square second, 0 to 6 km bulk shear 35 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
286 J/kg
Mixed-layer CIN
-66 J/kg
Surface CAPE
940 J/kg
Mixed-layer LCL
1037 m above ground
0-6 km bulk shear
35 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
51 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7
0-3 km lapse rate
4.4 K/km

Open this sounding in Storm Lab

Miami, FL (KMFL), 00:00Z

2.3 hours after it, 141 km from the path. November 23, 2017.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 00:00Z on 2017-11-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1315 joules per kilogram, CIN -1, lifted condensation level 791 meters above ground. Wind barbs in knots down the right edge.LCLEL10008507005003002001001 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, Miami, FL at 00:00Z on 2017-11-23The 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 -29 square meters per square second, 0 to 6 km bulk shear 41 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
1315 J/kg
Mixed-layer CIN
-1 J/kg
Surface CAPE
1686 J/kg
Mixed-layer LCL
791 m above ground
0-6 km bulk shear
41 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
-29 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
-0.1
Supercell composite
-0.8
0-3 km lapse rate
6.5 K/km

Open this sounding in Storm Lab

The surface observations

Immokalee Auxiliary (IMM), 13 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
19:55 UTC84.266.2 5 kt1012.5
20:15 UTC82.466.270° 5 kt1012.5
20:35 UTC82.466.280° 5 kt1012.5
20:55 UTC82.466.280° 6 kt1012.5
21:15 UTC80.66890° 10 kt1012.5
21:35 UTC78.866.270° 7 kt1012.5
21:55 UTC776860° 5 kt1012.9
22:15 UTC776840° 4 kt1013.2
22:35 UTC7766.270° 5 kt1013.2
22:55 UTC75.268250° 3 kt1013.9
23:15 UTC71.668310° 7 kt1014.6-RA
23:35 UTC69.868300° 6 kt1014.6

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

The radar

The Miami radar (KAMX), 143 km away, was scanning. The volume nearest the touchdown began at 21:40 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
21:40 UTCFUNNEL CLOUD6 W ImmokaleeCollier, FLCOLLIER COUNTY SO REPORTED THAT A DEPUTY AIRBORNE IN A HELICPTER REPORTED A FUNNEL CLOUD AT 440PM IN THE CORKSCREW AREA.
21:40 UTCTORNADO6 W ImmokaleeCollier, FLCOLLIER COUNTY SHERIFFS OFFICE REPORTED THAT A DEPUTY AIRBORNE IN A HELICPTER REPORTED A FUNNEL CLOUD AT 440PM IN THE CORKSCREW AREA. TWO VIDEOS ON SOCIAL MEDIA ORIGINALLY TAKEN BY MEMBERS OF THE GENERAL PUBLIC SHOWED A

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.