Tornadoes · United States · Florida · 2009

EF0 tornado, Harney, Florida, May 13, 2009

This EF0 tornado ran 1.4 miles across Hillsborough County on May 13, 2009, touching down at 6:33 PM EDT and reaching 30 yards wide. It killed nobody, and did $75,000 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
May 13, 2009
Touchdown
6:33 PM EDT (22:33 UTC)
Lifted
6:43 PM EDT (22:43 UTC)
On the ground
10 minutes
Path length
1.4 miles (2.2 km)
Path width
30 yards (27 m)
Deaths
0
Injuries
0
Property damage
$75,000
County
Hillsborough County
Touchdown point
28.017, -82.360
Lift-off point
28.018, -82.383
Record number
0905131633-01

What the Weather Service recorded

A remnant frontal boundary in place across north-central Florida combined with a warm, moist, unstable airmass and the east and west coast sea breeze boundaries to develop numerous thunderstorms across the area.

The tornado touched down briefly, snapping three power lines in an industrial park on Industrial Drive and moving through an open field before lifting and shifting its track to the southeast. The tornado then touched down again on Vanderbaker Road, moved across Grand Circle and East River Drive, before lifting along Broxburn Avenue. Several large but damaged trees were uprooted, including one that fell onto a house, numerous large branches were snapped off, and some decorative shutters were blown off of the front of a house along the path. Winds were estimated at 80mph.

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

The warnings

5 minutes of warning. NWS TBW issued a tornado warning for this county at 22:28 UTC, 5 minutes before the tornado touched down, in force until 22:45 UTC.

Issued (UTC)ExpiredProductOffice
22:15 UTC22:45 UTCSevere Thunderstorm WarningTBW
22:28 UTC22:45 UTCTornado WarningTBW
22:46 UTC00:45 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 General Thunderstorms Risk. The outlook in force was issued at 20:01 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

10.6 hours before the tornado, 35 km from the path. May 13, 2009.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2009-05-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 601 joules per kilogram, CIN -71, lifted condensation level 949 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, Tampa Bay, FL at 12:00Z on 2009-05-13The 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 57 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
601 J/kg
Mixed-layer CIN
-71 J/kg
Surface CAPE
676 J/kg
Mixed-layer LCL
949 m above ground
0-6 km bulk shear
6 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
84 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

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

1.4 hours after it, 35 km from the path. May 14, 2009.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 00:00Z on 2009-05-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 206 joules per kilogram, CIN -56, lifted condensation level 768 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, Tampa Bay, FL at 00:00Z on 2009-05-14The 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 -9 square meters per square second, 0 to 6 km bulk shear 19 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
206 J/kg
Mixed-layer CIN
-56 J/kg
Surface CAPE
257 J/kg
Mixed-layer LCL
768 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
31 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.4 K/km

Open this sounding in Storm Lab

The radar

The Tampa radar (KTBW), 35 km away, was scanning. The volume nearest the touchdown began at 22:32 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 UTCHAIL 15 Sw BrandonHillsborough, FLSPOTTER REPORTED QUARTER SIZED HAIL STARTED AT 620 PM EDT AT PALM RIVER ROAD AND MAYDELL ROAD
22:30 UTCTSTM WND DMG4 Ese LutzHillsborough, FLTREES REPORTED DOWN IN WOODED AREA NEAR APARTMENT COMMUNITY ON AMBERLY DRIVE, SOUTHWEST OF TAMPA PALMS.
22:33 UTCTORNADO3 Sse Temple TerraceHillsborough, FLMOTORIST DRIVING NORTH ON US HWY 301 REPORTS A TORNADO NEAR THE INTERSECTION OF INTERSTATE 4 AND HWY 301.
22:40 UTCTORNADO1 Se Temple TerraceHillsborough, FLSTATE WATCH OFFICE REPORTED A FUNNEL CLOUD PASSED OVER A BUILDING ON INDUSTRIAL DR. POWER LINES WERE REPORTED DOWN AROUND 640PM. POSSIBLE TORNADO.

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

This ground now

The live radar over the trackEvery 2009 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

The other tornadoes of May 13, 2009

19 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 135:10 PM CDTEF1Sullivan, MO4.31001$25,000
May 135:43 PM CDTEF1Adair, MO7.7100$100,000
May 135:52 PM CDTEF0Coffey, KS0.125
May 136:00 PM CDTEF0Coffey, KS0.025
May 136:09 PM CDTEF2Adair, MO5.815026$5.0 million
May 136:33 PM CDTEF0Knox, MO9.2200
May 136:49 PM CDTEF0Knox, MO3.1100
May 136:54 PM CDTEF0Kay, OK0.2100
May 136:55 PM CDTEF0Cowley, KS0.875
May 137:20 PM CDTEF1Noble, OK4.650
May 137:20 PM CDTEF1Bourbon, KS12.6300$100,000
May 139:26 PM CDTEF2Caddo, OK7.3250$50 million
May 139:49 PM CDTEF0Labette, KS0.350
May 1310:41 PM CDTEF0Cleveland, OK0.580
May 1311:38 PM CDTEF0Macoupin, IL1.640
May 1312:04 AM CDTEF1Christian, IL0.860$50,000
May 1312:12 AM CDTEF0Shelby, IL0.640$60,000
May 1312:22 AM CDTEF0Shelby, IL1.450$45,000
May 1312:23 AM CDTEF0Vermilion, IL0.150$35,000

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.