F1 tornado, Islamorada to Rock Harbor, Florida, November 4, 1998

1. F040 to 72 mph

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

2. F173 to 112 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. F2113 to 157 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. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 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

F1

Date

November 4, 1998

Touchdown

5:15 PM EST (22:15 UTC)

Path length

2.0 miles (3.2 km)

Path width

50 yards (46 m)

Deaths

0

Injuries

0

Property damage

$100,000

County

Monroe County

Touchdown point

24.920, -80.630

Lift-off point

24.920, -80.630

Record number

836

Tropical storm Mitch, after devastating portions of central America as a hurricane then dissipating over land, reformed over the Bay of Campeche and moved northeast across the Yucatan Peninsula, the southeast Gulf of Mexico and into south Florida. Casualties in south Florida included two drownings in a fishing boat that capsized near the Dry Tortugas and about 65 injuries, most of them minor, in the upper keys involving hurricane spawned tornadoes. Losses are estimated at $50 million, including $20 million in crop damage. Much of the property damage was caused by five tornadoes, one of which reached a maximum intensity of F2, in the upper Keys. A total of 646 dwellings were damaged in an area from Islamorada to north Key Largo. Other tornadoes were observed in Broward, Palm Beach, and Collier counties. Widespread rainfall totals across south Florida averaged 6 to 8 inches with local amounts of 13 inches. The storm surge of 2 to 4 feet along the Keys and southwest Florida coast, and 1 to 2 feet along the southeast coast, produced minor flooding, beach erosion and damage to marine structures and vessels. The maximum officially measured wind in south Florida was 52 knots (60 mph) with a peak wind of 57 knots (65 mph) at Fowey Rocks Light. The maximum wind on land was 35 knots (40 mph) with a peak wind of 48 knots (55 mph) at Key West International Airport. About 50,000 customers lost their electricity.

A tornado moved ashore from the Straits of Florida into the middle Keys near mile marker 80. It travelled in a northeast direction crossing to the west side of U.S. 1. Damage occurred to the roof of a motel and to trees, fences and power lines.

A tornado touched down just west of U.S. 1 near mile marker 98. Damage occurred to the roof of a house and to foliage.

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

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 Storm Prediction Center had this point in a Slight Risk. The outlook in force was issued at 10:24 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 live radar over the trackEvery 1998 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.