Tornadoes · United States · New York · 2005

F1 tornado, Glen Cove, New York, August 12, 2005

This F1 tornado ran 0.2 miles across Nassau County on August 12, 2005, touching down at 9:45 PM EDT and reaching 50 yards wide. It killed nobody, and did $140,000 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 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.

The record

Rating
F1
Date
August 12, 2005
Touchdown
9:45 PM EDT (01:45 UTC)
Path length
0.2 miles (0.3 km)
Path width
50 yards (46 m)
Deaths
0
Injuries
0
Property damage
$140,000
County
Nassau County
Touchdown point
40.870, -73.630
Lift-off point
40.870, -73.630
Record number
339

What the Weather Service recorded

A line of thunderstorms developed over the Lower Hudson Valley of NY on the evening of the 12th. As these thunderstorms progressed to the southeast, they produced wind damage. A brief tornado also touched down in Nassau County.

A weak and short-lived F1 tornado touched down around 945 pm EDT in Glen Cove. The tornado formed in a thunderstorm that formed on an outflow boundary produced by a line of thunderstorms over Long Island Sound. The tornado moved from northwest to southeast and was estimated to be on the ground for only a minute or two. However, it caused considerable damage to many of the large trees in the area. Many large trees in the neighborhood to the south of the Welwyn Preserve came down and did considerable damage to homes and property. Damage was reported as far southeast as North Shore University Hospital. There were no known injuries.

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 General Thunderstorms Risk. The outlook in force was issued at 00:46 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.

Brookhaven, NY (KOKX), 00:00Z

1.8 hours before the tornado, 64 km from the path. August 13, 2005.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 2005-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 575 joules per kilogram, CIN -54, lifted condensation level 1200 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, Brookhaven, NY at 00:00Z on 2005-08-13The 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 41 square meters per square second, 0 to 6 km bulk shear 34 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
575 J/kg
Mixed-layer CIN
-54 J/kg
Surface CAPE
2000 J/kg
Mixed-layer LCL
1200 m above ground
0-6 km bulk shear
34 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
81 m²/s²
Significant tornado parameter
0.1
Supercell composite
2.4
0-3 km lapse rate
6.0 K/km

Open this sounding in Storm Lab

Brookhaven, NY (KOKX), 12:00Z

10.2 hours after it, 64 km from the path. August 13, 2005.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 2005-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1693 joules per kilogram, CIN -85, lifted condensation level 1119 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, Brookhaven, NY at 12:00Z on 2005-08-13The 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 116 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
1693 J/kg
Mixed-layer CIN
-85 J/kg
Surface CAPE
1770 J/kg
Mixed-layer LCL
1119 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
18 kt
0-1 km storm-relative helicity
116 m²/s²
0-3 km storm-relative helicity
120 m²/s²
Significant tornado parameter
0.5
Supercell composite
1.3
0-3 km lapse rate
4.8 K/km

Open this sounding in Storm Lab

The radar

The Brookhaven radar (KOKX), 64 km away, was scanning. The volume nearest the touchdown began at 01:46 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
02:00 UTCTSTM WND DMGOyster BayNassau, NYFALLING LARGE LIMBS DOWNED SOME POWER LINES ACROSS A GOOD PORTION OF NORTHEASTERN NASSAU COUNTY

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

This ground now

The live radar over the trackEvery 2005 tornado in New YorkEvery tornado in New York since 1950Warnings in force in New York nowThe forecast where you are

The other tornadoes of August 12, 2005

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 122:24 PM EDTF0Allegany, NY0.510$10,000
August 122:45 PM EDTF1Steuben, NY1.0200$50,000
August 124:22 PM EDTF1Sullivan, PA0.730$10,000
August 125:10 PM EDTF0Bradford, PA1.0200$100,000
August 125:56 PM EDTF0Polk, FL0.540
August 124:40 PM MDTF2Campbell, WY1.5450213$5.0 million
August 127:05 PM MDTF0Converse, WY0.130

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.