Tornadoes · United States · Florida · 2008

EF0 tornado, Upper Key Largo, Florida, September 9, 2008

This EF0 tornado ran 0.4 miles across Monroe County on September 9, 2008, touching down at 1:50 PM EDT and reaching 100 yards wide. It killed nobody, and did $25,000 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
September 9, 2008
Touchdown
1:50 PM EDT (17:50 UTC)
Lifted
1:52 PM EDT (17:52 UTC)
On the ground
2 minutes
Path length
0.4 miles (0.6 km)
Path width
100 yards (91 m)
Deaths
0
Injuries
0
Property damage
$25,000
County
Monroe County
Touchdown point
25.168, -80.377
Lift-off point
25.169, -80.382
Record number
0809091150-01

What the Weather Service recorded

Hurricane Ike moved west to west-northwest across eastern Cuba, just offshore the south central coast, and then crossed through western Cuba into the Gulf of Mexico. Tropical storm force winds and two tornadoes were reported in the Florida Keys. However, rainfall amounts and storm surge were minimal.

Tornado touched down on Atlantic side of U.S. Highway One and moved toward the northwest. The tornado caused minor damage to facia on a business on the bayside of U.S. Highway One, then moved into a residential area. One residence with two broken windows, and another residence had an exterior wall penetrated with a 2x4 carried from over 250 yards away from a home under construction. Several trees and large limbs downed. Estimated maximum wind speed 60 to 70 mph.

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 Slight Risk, with a 0.05 chance of a tornado within 25 miles. The outlook in force was issued at 16:10 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

5.8 hours before the tornado, 73 km from the path. September 9, 2008.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 12:00Z on 2008-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2105 joules per kilogram, CIN -3, lifted condensation level 782 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 2008-09-09The 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 167 square meters per square second, 0 to 6 km bulk shear 19 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
2105 J/kg
Mixed-layer CIN
-3 J/kg
Surface CAPE
2235 J/kg
Mixed-layer LCL
782 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
28 kt
0-1 km storm-relative helicity
167 m²/s²
0-3 km storm-relative helicity
205 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
6.3 K/km

Open this sounding in Storm Lab

Miami, FL (KMFL), 00:00Z

6.2 hours after it, 73 km from the path. September 10, 2008.

Skew-T log-pSkew-T log-p diagram, Miami, FL at 00:00Z on 2008-09-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 3819 joules per kilogram, CIN 0, lifted condensation level 585 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 2008-09-10The 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 129 square meters per square second, 0 to 6 km bulk shear 16 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
3819 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
3608 J/kg
Mixed-layer LCL
585 m above ground
0-6 km bulk shear
16 kt
0-1 km bulk shear
25 kt
0-1 km storm-relative helicity
129 m²/s²
0-3 km storm-relative helicity
207 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
7.0 K/km

Open this sounding in Storm Lab

The surface observations

Homestead Afb (HST), 36 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
15:58 UTC83.4876.28100° 17 kt251011.5
16:21 UTC84.277100° 17 kt231011.2UP
16:32 UTC84.277100° 18 kt241011.2
16:46 UTC82.477100° 15 kt261011.2
16:58 UTC82.7675.74100° 19 kt241011.5
17:47 UTC82.475.2100° 12 kt221010.5-RA
17:58 UTC82.2275.2110° 10 kt221010.5-RA
18:00 UTC82.475.2110° 12 kt181010.5
18:21 UTC84.277100° 15 kt231010.5-DZ
18:38 UTC84.277110° 14 kt201010.2
18:58 UTC83.8476.6490° 15 kt211009.5-DZ
19:06 UTC84.277100° 16 kt241009.1
19:07 UTC84.277100° 19 kt261009.1UP
19:16 UTC84.277100° 18 kt261009.5TS UP
19:17 UTC84.277100° 18 kt261009.5TS

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

The radar

The Miami radar (KAMX), 49 km away, was scanning. The volume nearest the touchdown began at 17:49 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
14:55 UTCNON-TSTM WND GST 431 Wsw Homestead ParkMiami-Dade, FLMEASURED AT TURKEY POINT MARINE WXFLOW SITE.
15:45 UTCNON-TSTM WND GST 434 Sse KendallAmz630, FLMEASURED AT CUTLER WXFLOW MARINE SITE.
17:52 UTCTROPICAL STORM2 N Key LargoUpper Keys In Monr, FLPUBLIC REPORTED A 10 FOOT TREE WAS UPROOTED...AND SOME DAMAGE TO ALUMINUM SIDING AT HOME ON PLANTATION ROAD AT MILEMARKER 106.

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

This ground now

The live radar over the trackEvery 2008 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

The other tornadoes of September 9, 2008

1 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
September 96:34 PM CDTEF0Llano, TX0.910

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.