EF1 tornado, Ochopee, Florida, September 9, 2017

1. EF065 to 85 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mphthis tornado

   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.

Rating

EF1

Date

September 9, 2017

Touchdown

12:20 PM EDT (16:20 UTC)

Lifted

12:23 PM EDT (16:23 UTC)

On the ground

3 minutes

Path length

0.3 miles (0.4 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

County

Collier County

Touchdown point

25.902, -81.327

Lift-off point

25.900, -81.333

Record number

1709091020-01

1 damage points were recorded along this path by NWS MFL, in the Damage Assessment Toolkit the survey teams carry.

• Mearured damage inside shop on this floor to be 56 inches. That is 43 inches above the Wilma water mark. Therefore it is estimated Irma surge was around 3.5 ft higher than Wilma at this point or 9.1 ft NAVD88 or so. 6 FT AGL relative to the parking lot. This has to be confirmed with USGS tide gage placed there prior to event as water mark was not clear cut.

Survey points are preliminary and are the raw material the published rating was built from. Source: NWS Damage Assessment Toolkit.

Major Hurricane Irma made landfall in Southwest Florida on Marco Island as a Category 3 hurricane around 330 PM EDT on September 10th. The storm traveled north through southwest Florida through the evening. Effects from Irma were felt across South Florida from September 9th through September 11th. Irma had reached Category 5 strength and a minimum central pressure of 914 MB east of the Bahamas, maintaining Category 5 intensity until landfall along the north coast of Cuba on September 9th. Irma made its first Florida landfall in the Lower Florida Keys early on September 10th as a Category 4 hurricane. ||The strength and size of Hurricane Irma allowed for impacts to be felt across all of South Florida. Irma brought widespread wind damage, heavy rainfall and storm surge to all areas. Hurricane-force sustained wind were measured in much of Collier County, as well as far southern and inland Miami-Dade County, with the possibility of additional hurricane-force sustained wind in more isolated areas over the remainder of South Florida where widespread tropical storm force sustained wind occurred. Gusts to hurricane force were felt over all of South Florida, with the maximum measured wind gust of 142 mph in Naples in Collier County. Widespread tree damage and some structural damage occurred across all of South Florida, with most structural damage on the minor side.||Irma brought a significant storm surge on both coasts of South Florida. Storm surge of 6 to 8 feet was observed in the Everglades City and Goodland areas of Collier County, with 3 to 5 feet from Marco Island to Naples. Along the east coast, observed storm surge values of 4 to 6 feet were noted along Biscayne Bay from south of Miami to Homestead, and 2 to 4 feet elsewhere along the east coast from Key Biscayne to Palm Beach.||Hurricane Irma brought widespread rainfall and some flooding across the region. From the period between 8 AM EDT September 9th and 8 AM EDT September 11th, 8 to 15 inches of rain were measured over interior portions of Southwest Florida, with estimated amounts of 16 to 20 inches in southwestern Hendry County. This rainfall near the end of a wet summer led to significant flooding over these areas. 5 to 10 inches of rain were noted elsewhere across South Florida, with areas of minor to moderate flooding. ||32 deaths were attributed to Irma in southern Florida, all but one indirect. The only direct death was an 86-year-old man who was knocked down by a gust of wind while opening the front door of his home in Broward County. Most of the deaths occurred during cleanup after the storm, as well as several as a result of carbon monoxide poisoning from misuse of generators. Initial and incomplete damage estimate across the area is estimated to be around $800 million, but in all likelihood will be much higher once damage assessments are completed. $222.5 million in damage came in from Collier County, and about $300 million from Palm Beach County. About $255 million came from the agricultural community in Miami-Dade County.||Total number of people who were at county evacuation shelters were as follows: Miami-Dade County - 31,092, Palm Beach County - 17,263, Collier County - 17,040, Broward County - 17,000, Hendry County - 3,000||Total number of customers without power were as follows: Miami-Dade County - 888,530, Broward County - 689,000, Palm Beach County- 566,240, Collier County - 197,630, Hendry County - 9,700, Glades County - 1,670.

NWS storm survey determined damage including leaning wood power poles along US 41 and SR 29 were due to a tornado. Time estimated by radar.

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

12 minutes of warning. NWS MFL issued a tornado warning for this county at 16:08 UTC, 12 minutes before the tornado touched down, in force until 16:30 UTC.

The county was under a tornado watch, issued at 16:10 UTC and running to 03:50 UTC.

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 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 12:52 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 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.

The Miami radar (KAMX), 97 km away, was scanning. The volume nearest the touchdown began at 16:20 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.

The live radar over the trackEvery 2017 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

5 more were confirmed in the United States that day.

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.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.