Tornadoes · United States · Florida · 2018
EF0 tornado, Oak Knoll, Florida, December 20, 2018
This EF0 tornado ran 0.2 miles across Manatee County on December 20, 2018, touching down at 8:32 AM EST and reaching 125 yards wide. It killed nobody, and did $30,000 of property damage.
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.
EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- December 20, 2018
- Touchdown
- 8:32 AM EST (13:32 UTC)
- Lifted
- 8:33 AM EST (13:33 UTC)
- On the ground
- 1 minutes
- Path length
- 0.2 miles (0.3 km)
- Path width
- 125 yards (114 m)
- Deaths
- 0
- Injuries
- 0
- Property damage
- $30,000
- County
- Manatee County
- Touchdown point
- 27.461, -82.228
- Lift-off point
- 27.464, -82.228
- Record number
- 1812200732-01
What the Weather Service recorded
A strong cold front moved southeast through the eastern Gulf of Mexico and Florida Peninsula on the 20th, preceded by a squall line. The storms produced 4 tornadoes, and damaging wind gusts, in addition to strong gradient winds behind the front on the 21st. The strong onshore winds also produced coastal flooding along the coast and moderate to major beach erosion from Pinellas County to Lee County. .
Broadcast media report that damage included a car port was destroyed, trees that fell on a shed, numerous branches knocked down along a narrow path.
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.
The county was under a tornado watch, issued at 12:55 UTC and running to 18:07 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 06:00 UTC | 08:09 UTC | Flood Watch | TBW |
| 12:40 UTC | 13:00 UTC | Tornado Warning | TBW |
| 12:55 UTC | 18:07 UTC | Tornado Watch | TBW |
| 14:24 UTC | 14:45 UTC | Tornado Warning | TBW |
| 14:25 UTC | 15:00 UTC | Tornado Warning | TBW |
| 14:54 UTC | 16:45 UTC | Flood Advisory | TBW |
| 16:21 UTC | 17:00 UTC | Severe Thunderstorm Warning | TBW |
| 16:39 UTC | 18:15 UTC | Flood Advisory | TBW |
| 16:54 UTC | 17:17 UTC | Tornado Warning | TBW |
| 17:01 UTC | 17:29 UTC | Severe Thunderstorm Warning | TBW |
| 18:21 UTC | 19:45 UTC | Flood Advisory | TBW |
| 21:51 UTC | 13:24 UTC | Flood Warning | TBW |
| 00:00 UTC | 00:36 UTC | Flood Warning | TBW |
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 Enhanced Risk, with a 0.10 chance of a tornado within 25 miles. The outlook in force was issued at 12:58 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.
Tampa Bay, FL (KTBW), 12:00Z
1.5 hours before the tornado, 32 km from the path. December 20, 2018.
- Mixed-layer CAPE
- 620 J/kg
- Mixed-layer CIN
- -264 J/kg
- Surface CAPE
- 539 J/kg
- Mixed-layer LCL
- 569 m above ground
- 0-6 km bulk shear
- 57 kt
- 0-1 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 318 m²/s²
- 0-3 km storm-relative helicity
- 316 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.9
- 0-3 km lapse rate
- 4.9 K/km
Tampa Bay, FL (KTBW), 00:00Z
10.5 hours after it, 32 km from the path. December 21, 2018.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -69969 J/kg
- Surface CAPE
- 2 J/kg
- Mixed-layer LCL
- 668 m above ground
- 0-6 km bulk shear
- 71 kt
- 0-1 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 210 m²/s²
- 0-3 km storm-relative helicity
- 48 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.3 K/km
The surface observations
Sarasota-Bradenton (SRQ), 33 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 11:34 UTC | 68 | 67 | 190° 7 kt | 1007.1 | +RA BR | |
| 11:35 UTC | 190° 9 kt | 1007.1 | +RA BR | |||
| 11:40 UTC | 180° 13 kt | 1007.5 | +RA BR | |||
| 11:45 UTC | 170° 16 kt | 1007.1 | +RA BR | |||
| 11:50 UTC | 180° 16 kt | 1007.1 | +RA BR | |||
| 11:53 UTC | 70 | 68 | 170° 14 kt | 1007.1 | +TSRA BR | |
| 11:55 UTC | 170° 15 kt | 1007.1 | +RA BR | |||
| 12:00 UTC | 170° 14 kt | 1007.1 | +RA BR | |||
| 12:05 UTC | 71 | 69 | 160° 14 kt | 1007.1 | +TSRA BR | |
| 12:05 UTC | 160° 13 kt | 1007.1 | +RA BR | |||
| 12:07 UTC | 71 | 69 | 170° 12 kt | 1007.1 | +RA BR | |
| 12:10 UTC | 170° 12 kt | 1007.1 | +RA BR | |||
| 12:15 UTC | 180° 12 kt | 1007.1 | +RA BR | |||
| 12:20 UTC | 170° 13 kt | 1007.1 | +RA BR | |||
| 12:30 UTC | 180° 10 kt | 1007.1 | +RA BR | |||
| 12:35 UTC | 180° 10 kt | 1007.1 | RA BR | |||
| 12:40 UTC | 180° 9 kt | 1006.8 | RA BR | |||
| 12:41 UTC | 69 | 68 | 180° 9 kt | 1006.8 | RA BR | |
| 12:45 UTC | 190° 9 kt | 1006.8 | RA BR | |||
| 12:48 UTC | 69.8 | 68 | 190° 8 kt | 1006.8 | VCTS RA BR | |
| 12:50 UTC | 190° 7 kt | 1006.8 | RA BR | |||
| 12:53 UTC | 69 | 68 | 190° 9 kt | 1006.8 | VCTS RA BR | |
| 12:55 UTC | 180° 9 kt | 1006.4 | RA BR | |||
| 12:58 UTC | 69 | 68 | 180° 9 kt | 1006.4 | RA BR | |
| 13:00 UTC | 190° 7 kt | 1006.8 | RA BR | |||
| 13:05 UTC | 200° 12 kt | 1007.1 | +RA BR | |||
| 13:06 UTC | 69 | 68 | 210° 12 kt | 1007.1 | +RA BR | |
| 13:10 UTC | 220° 13 kt | 1007.1 | +RA BR | |||
| 13:14 UTC | 69 | 67 | 220° 9 kt | 1006.8 | RA BR | |
| 13:15 UTC | 230° 8 kt | 1006.8 | RA BR | |||
| 13:20 UTC | 270° 5 kt | 1006.8 | RA BR | |||
| 13:21 UTC | 68 | 67 | 280° 5 kt | 1006.8 | RA BR | |
| 13:25 UTC | 310° 6 kt | 1006.8 | RA BR | |||
| 13:30 UTC | 330° 5 kt | 1006.8 | +RA BR | |||
| 13:35 UTC | 330° 3 kt | 1007.1 | +RA BR | |||
| 13:40 UTC | 0° 0 kt | 1007.5 | +RA BR | |||
| 13:45 UTC | 0° 0 kt | 1007.5 | +RA BR | |||
| 13:50 UTC | 190° 4 kt | 1007.1 | +RA BR | |||
| 13:53 UTC | 68 | 66 | 150° 4 kt | 1007.1 | +RA BR | |
| 13:55 UTC | 150° 4 kt | 1006.8 | +RA BR | |||
| 14:00 UTC | 160° 3 kt | 1007.1 | RA BR | |||
| 14:05 UTC | 130° 6 kt | 1006.8 | +RA BR | |||
| 14:10 UTC | 140° 8 kt | 1006.8 | +RA BR | |||
| 14:15 UTC | 170° 8 kt | 1006.4 | +RA BR | |||
| 14:20 UTC | 160° 10 kt | 1006.8 | RA BR | |||
| 14:20 UTC | 68 | 67 | 160° 10 kt | 16 | 1006.8 | RA BR |
| 14:25 UTC | 170° 10 kt | 1006.4 | +RA BR | |||
| 14:30 UTC | 170° 10 kt | 1006.4 | +RA BR | |||
| 14:35 UTC | 180° 7 kt | 1006.8 | +RA BR | |||
| 14:36 UTC | 69 | 67 | 180° 7 kt | 1006.8 | +RA BR | |
| 14:40 UTC | 180° 9 kt | 1006.8 | +RA BR | |||
| 14:44 UTC | 69 | 67 | 170° 8 kt | 1006.8 | +RA BR | |
| 14:45 UTC | 180° 9 kt | 1006.8 | +RA BR | |||
| 14:50 UTC | 180° 12 kt | 1006.4 | +RA BR | |||
| 14:53 UTC | 69 | 67 | 200° 11 kt | 1006.4 | +RA BR | |
| 14:55 UTC | 190° 11 kt | 1006.1 | +RA BR | |||
| 15:00 UTC | 180° 13 kt | 1006.1 | +RA BR | |||
| 15:01 UTC | 69 | 67 | 190° 12 kt | 1006.1 | +RA BR | |
| 15:05 UTC | 69 | 67 | 200° 12 kt | 1006.1 | RA BR | |
| 15:05 UTC | 200° 12 kt | 1006.1 | RA BR | |||
| 15:08 UTC | 69 | 67 | 200° 11 kt | 1006.4 | TSRA BR | |
| 15:10 UTC | 190° 11 kt | 1006.4 | -RA BR | |||
| 15:15 UTC | 69 | 67 | 190° 11 kt | 1006.1 | TSRA BR | |
| 15:15 UTC | 190° 11 kt | 1006.1 | RA BR | |||
| 15:20 UTC | 190° 12 kt | 1006.1 | RA BR | |||
| 15:25 UTC | 200° 10 kt | 1005.8 | -RA BR | |||
| 15:30 UTC | 16 kt | 1005.8 | RA BR | |||
| 15:31 UTC | 69 | 67 | 240° 17 kt | 22 | 1005.8 | TSRA BR |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Tampa radar (KTBW), 32 km away, was scanning. The volume nearest the touchdown began at 13:28 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) | Report | Where | County | Remark |
|---|---|---|---|---|
| 12:40 UTC | TORNADO | 9 Nnw Myakka City | Manatee, FL | PORCH OFF HOUSE AND TREES DOWN ALONG KIBLER RANCH ROAD. |
| 13:50 UTC | TORNADO 0 | 2 E Fort Meade | Polk, FL | DELAYED... EARLIER RADAR SIGNATURE SUGGESTED A TORNADO MOVED TO THE NORTH,JUST EAST OF FORT MEADE. SHERIFF OFFICE REPORTED TO EMERGENCY MANAGEMENT THAT TREES WERE DOWN NEAR US 98 AND POOL BRANCH ROAD BUT NO BUILDINGS SUS |
| 16:01 UTC | TSTM WND GST 45 | Sarasota Bradenton Airp | Manatee, FL | ASOS AT SARASOTA-BRADENTON REPORTED A 45 MPH WIND GUST. |
| 16:04 UTC | TSTM WND DMG | 4 S Sarasota | Sarasota, FL | PUBLIC RELAYED VIA SOCIAL MEDIA A TREE BLOCKING ROADWAY ON MIDNIGHT PASS ROAD NEAR HIDDEN HARBOR WAY IN SIESTA KEY. TIME IS RADAR ESTIMATED. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2018 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are
The other tornadoes of December 20, 2018
4 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| December 20 | 8:45 AM EST | EF0 | Polk, FL | 0.8 | 75 | $5,000 | ||
| December 20 | 9:14 AM EST | EF0 | Polk, FL | 0.1 | 30 | 1 | $45,000 | |
| December 20 | 12:28 PM EST | EF0 | Charlotte, FL | 1.0 | 100 | $30,000 | ||
| December 20 | 5:10 PM EST | EF0 | New Hanover, NC | 0.3 | 40 | $30,000 |
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.