Tornadoes · United States · Florida · 2018

EF0 tornado, Fort Meade to Crooked Lake Park, Florida, December 20, 2018

From Fort Meade to Crooked Lake Park, this EF0 tornado ran 0.1 miles across Polk County on December 20, 2018, touching down at 9:14 AM EST and reaching 30 yards wide. It killed nobody and injured 1, and did $45,000 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.

  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
December 20, 2018
Touchdown
9:14 AM EST (14:14 UTC)
Lifted
9:15 AM EST (14:15 UTC)
On the ground
1 minutes
Path length
0.1 miles (0.1 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
1
Property damage
$45,000
County
Polk County
Touchdown point
27.829, -81.601
Lift-off point
27.830, -81.601
Record number
1812200814-01

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. .

The sheriff's office reported trees uprooted near US 98 and Pool Branch Road but no structures were affected. The only damage indicator is hardwood trees uprooted.

Damage was found to the southeast side of a 4-unit duplex. The southeast unit sustained partial uplift of roofing material and broken windows on the east side of the building. Some roof damage extended to the the northeast unit as well. The building was built before the building code changes in the mid 1990s. Estimated damage including contents is $45,000.

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 19:43 UTC.

Issued (UTC)ExpiredProductOffice
12:55 UTC19:43 UTCTornado WatchTBW
13:01 UTC13:30 UTCTornado WarningTBW
13:15 UTC13:45 UTCTornado WarningTBW
13:43 UTC14:04 UTCTornado WarningTBW
14:21 UTC14:33 UTCTornado WarningTBW
14:37 UTC15:00 UTCTornado WarningTBW
14:48 UTC15:15 UTCTornado WarningTBW
14:54 UTC16:45 UTCFlood AdvisoryTBW
16:13 UTC16:32 UTCTornado WarningTBW
16:39 UTC18:15 UTCFlood AdvisoryTBW
17:01 UTC17:45 UTCSevere Thunderstorm WarningTBW
18:21 UTC19:45 UTCFlood AdvisoryTBW

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

2.2 hours before the tornado, 80 km from the path. December 20, 2018.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2018-12-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 620 joules per kilogram, CIN -264, lifted condensation level 569 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, Tampa Bay, FL at 12:00Z on 2018-12-20The 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 318 square meters per square second, 0 to 6 km bulk shear 57 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
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

Open this sounding in Storm Lab

Tampa Bay, FL (KTBW), 00:00Z

9.8 hours after it, 80 km from the path. December 21, 2018.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 00:00Z on 2018-12-21Temperature 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 -69969, lifted condensation level 668 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 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, Tampa Bay, FL at 00:00Z on 2018-12-21The 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 210 square meters per square second, 0 to 6 km bulk shear 71 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
-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

Open this sounding in Storm Lab

The radar

The Tampa radar (KTBW), 80 km away, was scanning. The volume nearest the touchdown began at 14:14 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
13:50 UTCTORNADO 02 E Fort MeadePolk, FLDELAYED... 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
14:15 UTCTORNADOCrooked Lake ParkPolk, FL*** 1 INJ *** ROOF DAMAGE TO HOME ON GENESIS POINTE DRIVE FROM POSSIBLE TORNADO.
16:30 UTCTSTM WND GST 48Ese LacoocheePolk, FLPEAK GUST OF 48 MPH IN LAKELAND HIGHLANDS.

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.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
December 208:32 AM ESTEF0Manatee, FL0.2125$30,000
December 208:45 AM ESTEF0Polk, FL0.875$5,000
December 2012:28 PM ESTEF0Charlotte, FL1.0100$30,000
December 205:10 PM ESTEF0New Hanover, NC0.340$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.