Tornadoes · United States · Florida · 1978

F2 tornado, Alachua County, Florida, May 4, 1978

This F2 tornado ran 12.8 miles across Alachua County on May 4, 1978, touching down at 6:30 AM EDT and reaching 300 yards wide. It killed nobody and injured 4, and did $500,000 to $5 million of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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 mph

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

  3. F2113 to 157 mphthis tornado

    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.

The record

Rating
F2
Date
May 4, 1978
Touchdown
6:30 AM EDT (10:30 UTC)
Path length
12.8 miles (20.6 km)
Path width
300 yards (274 m)
Deaths
0
Injuries
4
Property damage
$500,000 to $5 million
County
Alachua County
Touchdown point
29.570, -82.450
Lift-off point
29.680, -82.280
Record number
174

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.

Jacksonville, FL (KAYS), 00:00Z

10.5 hours before the tornado, 116 km from the path. May 4, 1978.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 00:00Z on 1978-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 264 joules per kilogram, CIN -112, lifted condensation level 671 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, Jacksonville, FL at 00:00Z on 1978-05-04The 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 183 square meters per square second, 0 to 6 km bulk shear 64 knots.19395878Sfc1 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
264 J/kg
Mixed-layer CIN
-112 J/kg
Surface CAPE
299 J/kg
Mixed-layer LCL
671 m above ground
0-6 km bulk shear
64 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
183 m²/s²
0-3 km storm-relative helicity
255 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4
0-3 km lapse rate
5.0 K/km

Open this sounding in Storm Lab

Jacksonville, FL (KAYS), 12:00Z

1.5 hours after it, 116 km from the path. May 4, 1978.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 12:00Z on 1978-05-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 7 joules per kilogram, CIN -495, lifted condensation level 1139 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, Jacksonville, FL at 12:00Z on 1978-05-04The 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 543 square meters per square second, 0 to 6 km bulk shear 74 knots.1939587897Sfc1 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
7 J/kg
Mixed-layer CIN
-495 J/kg
Surface CAPE
39 J/kg
Mixed-layer LCL
1139 m above ground
0-6 km bulk shear
74 kt
0-1 km bulk shear
38 kt
0-1 km storm-relative helicity
543 m²/s²
0-3 km storm-relative helicity
538 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

The surface observations

Gainesville Regional (GNV), 11 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
09:00 UTC7371140° 13 kt1003.4-TSRA
10:00 UTC7371140° 11 kt1003.7
11:00 UTC6868240° 10 kt1004.4
11:43 UTC320° 4 kt1004.7
12:00 UTC6767170° 8 kt1004.1
12:17 UTC270° 5 kt1004.7

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

This ground now

The live radar over the trackEvery 1978 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

The other tornadoes of May 4, 1978

14 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 43:10 AM EDTF0Bradford, FL0.113
May 45:30 AM EDTF0Dixie, FL0.113$5,000 to $50,000
May 49:00 AM EDTF0Saint Johns, FL0.113$5,000 to $50,000
May 411:00 AM EDTF0Saint Johns, FL0.210$500 to $5,000
May 411:45 AM EDTF0Pasco, FL0.113$500 to $5,000
May 411:47 AM EDTF3Pinellas, FL1.5200394$500,000 to $5 million
May 41:55 PM EDTF0Putnam, FL0.113$500 to $5,000
May 43:20 PM EDTF1Highlands, FL0.5502$500,000 to $5 million
May 43:50 PM EDTF0Osceola, FL0.1131$5,000 to $50,000
May 44:00 PM EDTF0Highlands, FL0.120$5,000 to $50,000
May 44:30 PM MDTF1Fall River, SD0.2200$500 to $5,000
May 46:50 PM EDTF2Clarendon, SC41.21501$50,000 to $500,000
May 45:50 PM CDTF0Sherman, TX11.360$50,000 to $500,000
May 47:00 PM EDTF1Kershaw, SC0.6100$500 to $5,000

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.