Tornadoes · United States · Florida · 2017

EF0 tornado, Samoset, Florida, August 26, 2017

This EF0 tornado ran 0.3 miles across Manatee County on August 26, 2017, touching down at 9:19 PM EDT and reaching 50 yards wide. It killed nobody, and did $20,000 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
August 26, 2017
Touchdown
9:19 PM EDT (01:19 UTC)
Lifted
9:22 PM EDT (01:22 UTC)
On the ground
3 minutes
Path length
0.3 miles (0.5 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$20,000
County
Manatee County
Touchdown point
27.477, -82.554
Lift-off point
27.475, -82.549
Record number
1708261919-01

What the Weather Service recorded

A trough of low pressure developed over the eastern Gulf of Mexico and passed east across the Florida Peninsula on the 26th through 28th of August, bringing abundant tropical moisture into the area. Heavy rain fell across the area each day, with some areas seeing over 16 inches of rain totals throughout the event. Flood waters entered numerous homes in Hillsborough, Manatee, Sarasota, and Lee counties, as well as making numerous roads impassable and stalling vehicles. The flooding also caused two separate drowning deaths in the area. ||In addition to the flooding, the storms produced some wind damage and a brief EF-0 tornado in Manatee County.

A narrow path of damage was found in Samoset, with minor damage occurring at a County Public Works Facility. A couple of witnesses also reported seeing a funnel cloud in the area. Aluminum debris was thrown around, and several trees and large branches were knocked down. The time of the tornado was estimated from radar.

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.

Issued (UTC)ExpiredProductOffice
12:00 UTC01:00 UTCRip Currents StatementTBW
19:12 UTC21:15 UTCFlood AdvisoryTBW
00:28 UTC02:30 UTCFlood AdvisoryTBW
01:19 UTC04:15 UTCFlash Flood WarningTBW
05:16 UTC08:15 UTCFlood AdvisoryTBW
07:45 UTC00:00 UTCFlood WatchTBW
08:08 UTC18:00 UTCFlood WarningTBW
10:46 UTC15:48 UTCFlood WarningTBW
14:57 UTC18:52 UTCFlood AdvisoryTBW
15:38 UTC18:30 UTCFlood WarningTBW

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 00:37 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), 00:00Z

1.3 hours before the tornado, 29 km from the path. August 27, 2017.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 00:00Z on 2017-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 2698 joules per kilogram, CIN -2, lifted condensation level 608 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 00:00Z on 2017-08-27The 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 76 square meters per square second, 0 to 6 km bulk shear 7 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
2698 J/kg
Mixed-layer CIN
-2 J/kg
Surface CAPE
4954 J/kg
Mixed-layer LCL
608 m above ground
0-6 km bulk shear
7 kt
0-1 km bulk shear
14 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Tampa Bay, FL (KTBW), 12:00Z

10.7 hours after it, 29 km from the path. August 27, 2017.

Skew-T log-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2017-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1128 joules per kilogram, CIN -23, lifted condensation level 693 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 2017-08-27The 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 64 square meters per square second, 0 to 6 km bulk shear 15 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
1128 J/kg
Mixed-layer CIN
-23 J/kg
Surface CAPE
2122 J/kg
Mixed-layer LCL
693 m above ground
0-6 km bulk shear
15 kt
0-1 km bulk shear
16 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
114 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.5 K/km

Open this sounding in Storm Lab

The surface observations

Sarasota-Bradenton (SRQ), 8 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
23:20 UTC 1011.5RA BR
23:25 UTC240° 12 kt1011.9RA BR
23:30 UTC240° 16 kt1011.9+RA BR
23:31 UTC7978240° 18 kt231011.9+TSRA BR
23:35 UTC 1011.5+RA FG
23:38 UTC7979210° 18 kt251011.5+TSRA FG
23:40 UTC 1011.5+RA FG
23:45 UTC 1012.2+RA FG
23:46 UTC7979190° 14 kt261012.2+TSRA BR
23:50 UTC 1011.9+RA BR
23:53 UTC7979190° 14 kt251011.9+TSRA BR
23:55 UTC 1011.9+RA BR
00:00 UTC 241011.5+RA BR
00:05 UTC7979200° 15 kt261011.5+TSRA FG
00:10 UTC 1011.2+RA FG
00:15 UTC 1011.2+RA BR
00:20 UTC8080210° 16 kt271011.2+TSRA BR
00:25 UTC230° 12 kt171011.9-RA BR
00:28 UTC8181230° 11 kt211011.9-TSRA BR
00:30 UTC240° 11 kt1011.9+RA BR
00:34 UTC8181220° 10 kt171011.9+TSRA BR
00:35 UTC220° 10 kt1011.9+RA BR
00:40 UTC250° 14 kt191011.9+RA BR
00:45 UTC250° 15 kt1011.9+RA BR
00:50 UTC 1012.2+RA BR
00:53 UTC8080280° 19 kt251012.2+TSRA BR
00:55 UTC 1012.2+RA BR
00:56 UTC7979270° 22 kt271012.2+TSRA BR
01:00 UTC 1012.2+RA FG
01:05 UTC 1012.2+RA FG
01:10 UTC260° 15 kt1011.9+RA BR
01:13 UTC7878270° 16 kt221012.2+TSRA BR
01:15 UTC270° 16 kt1012.5+RA BR
01:20 UTC280° 15 kt1012.5+RA BR
01:25 UTC 1012.5+RA BR
01:30 UTC290° 13 kt1012.5+RA BR
01:35 UTC 1012.5+RA BR
01:39 UTC7676320° 12 kt1013.2+TSRA BR
01:40 UTC310° 12 kt1013.2+RA BR
01:45 UTC 1013.2+RA BR
01:50 UTC 1013.2+RA BR
01:53 UTC7575330° 11 kt221013.2+TSRA BR
01:55 UTC320° 11 kt1013.2+RA BR
02:00 UTC 1013.5+RA BR
02:05 UTC 1013.5+RA BR
02:07 UTC7575320° 12 kt231013.5+TSRA BR
02:10 UTC310° 6 kt1013.5+RA BR
02:15 UTC75750° 0 kt1013.5+TSRA BR
02:20 UTC130° 6 kt1013.2+RA BR
02:24 UTC7575190° 4 kt1013.2+TSRA BR
02:25 UTC210° 4 kt1013.2+RA BR
02:30 UTC260° 7 kt1013.2+RA BR
02:33 UTC7676270° 9 kt1013.2+TSRA BR
02:35 UTC290° 11 kt1013.2+RA BR
02:37 UTC7676310° 10 kt1013.2VCTS +RA BR
02:40 UTC320° 7 kt1012.9+RA BR
02:45 UTC7676320° 7 kt1012.9TSRA BR
02:50 UTC300° 6 kt1013.2-RA BR
02:53 UTC7676290° 6 kt1013.2TSRA BR
02:55 UTC290° 8 kt1013.2RA BR
03:00 UTC280° 11 kt1013.2RA BR
03:05 UTC290° 11 kt1012.9RA BR
03:08 UTC7676290° 10 kt1013.2RA BR
03:10 UTC290° 8 kt1013.2RA BR
03:15 UTC300° 8 kt1013.2-RA
03:16 UTC7777300° 8 kt1013.2VCTS -RA

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

The radar

The Tampa radar (KTBW), 29 km away, was scanning. The volume nearest the touchdown began at 01:18 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
00:45 UTCFLASH FLOOD4 Ese SamosetManatee, FLEMERGENCY MANAGER REPORTED FLOODED AND FLOATING CARS ON STATE ROAD 70 NEAR I-75. AT LEAST ONE WATER RESCUE WAS NEEDED.
01:21 UTCTORNADO2 Ese BradentonManatee, FLREPORT FROM LAST EVENING. DAMAGE AT A MANATEE COUNTY PUBLIC WORKS FACILITY. ALUMINUM DEBRIS AND TREES AND BRANCHES DOWNED.
01:45 UTCFLASH FLOOD3 Wnw BradentonManatee, FLAMATEUR RADIO OPERATOR NEAR MANATEE RIVER IN DOWNTOWN BRADENTON REPORTED 7 INCHES OF RAIN.
02:00 UTCFLASH FLOOD1 Wnw BradentonManatee, FLNWS EMPLOYEE REPORTS PARTS OF MANATEE AVE WEST IS UNDER ONE FOOT OF FLOWING WATER.
02:00 UTCFLASH FLOOD1 Wnw BradentonManatee, FLNWS EMPLOYEE REPORTS WATER IN HOMES OFF MANATEE AVE WEST AROUND 38TH STREET WEST

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

The other tornadoes of August 26, 2017

12 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 262:10 AM CDTEF0Wharton, TX1.430
August 262:12 AM CDTEF0Fort Bend, TX0.130$30,000
August 264:30 AM CDTEF0Harris, TX1.030$100,000
August 265:00 AM CDTEF1Fort Bend, TX0.950$1.3 million
August 268:05 AM CDTEF0Brazos, TX0.220
August 2612:22 PM CDTEF0Cameron Parish, LA1.725$7,000
August 263:50 PM CDTEF1Harris, TX0.950$500,000
August 263:20 PM MDTEF0Fall River, SD0.710
August 264:20 PM CDTEF0Harris, TX0.550$30,000
August 265:23 PM CDTEF0Wharton, TX0.530$50,000
August 268:15 PM CDTEF1Fort Bend, TX5.8100$2.0 million
August 2612:00 AM CDTEF0Harris, TX0.030$50,000

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.