Tornadoes · United States · New York · 1999

F2 tornado, Mattituck to New Suffolk, New York, August 8, 1999

From Mattituck to New Suffolk, this F2 tornado ran 4.0 miles across Suffolk County on August 8, 1999, touching down at 8:28 AM EDT and reaching 300 yards wide. It killed nobody and injured 1, and did $1.0 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
August 8, 1999
Touchdown
8:28 AM EDT (12:28 UTC)
Path length
4.0 miles (6.4 km)
Path width
300 yards (274 m)
Deaths
0
Injuries
1
Property damage
$1.0 million
County
Suffolk County
Touchdown point
41.000, -72.520
Lift-off point
41.000, -72.470
Record number
642

What the Weather Service recorded

A cluster of severe thunderstorms formed north of an approaching strong warm front and moved east-southeast, just north of the front.A severe thunderstorm produced a tornado along the south shore of the North Fork of Suffolk County on Long Island. The tornado touched down and lifted several times along a 4 mile path as it moved east-southeast from just southeast of Mattituck Air Base, across Marratooka Pt., Kimogener Pt. (of New Suffolk), Cutchogue Harbor, Central Nassau Pt., then lifted as it crossed Hog Neck Bay.The National Weather Service Survey showed that the tornado touched down first in southern sections of Mattituck. This was in the backyard area bounded to the west by Marratooka Road, to the north by Center Street, and to the south by Park Ave. Most damage at this location was to trees, where many tops were twisted off and several snapped off at 5 to 15 feet above the ground. This was estimated as F1 damage. The tornado "bounced" and continued east to the dirt road extension of Park Ave., where it lifted the roof off a cottage at #520. The roof of the building detached from the house and was carried about 115 feet to the northeast.The tornado continued east for about 1/2 mile, then touched down again at 10 Kimogenor Point. It ripped off the porch and part of the main roof of the house. It apparently developed a few separate vortices at this location. One twisted a 100 year old metal windmill over high tension power lines and did some significant damage to large trees. Another vortex slammed into the front porch at 2 Kimogenor Point. It ripped off the porch and a large section of the roof of the house. The lone inhabitant said he saw a "wall of water" heading toward his house and instinctively dove into the stone fireplace to protect himself as the storm hit. Winds were estimated over 100 mph over this part of the tornado's path.The tornado continued east along Jackson Ave. causing havoc with many mature trees in the area. The most significant damage occurred in the vicinity of Jackson Ave. and Fifth Street, where winds were estimated from 110 to 120 mph, due to the devastation to many large trees. This was the area where F2 damage was observed. This was also the widest path width, which was estimated at 300 yards.The tornado continued east along Jackson Ave. creating F1 damage then went over Cutchogue Harbor. Eyewitnesses from Nassau Point (Little Hog Neck) said they saw the tornado over the water just east of New Suffolk. They saw several suction vortices rotating around the main funnel. The tornado moved across Nassau Point, in the vicinity of Wunnaweta Pond, where it twisted and sheared off many trees that fell on and damaged houses. It bounced again and hit close to the ground near #6225 and #6325 Nassau Point Road. Many trees fell onto and damaged homes. These backyards were on top of a cliff overlooking Hogs Neck Bay. The tornado lifted before hitting these homes. This was the last indication of tornadic damage.The latest cost estimates of damage from the Southhold Supervisor's Office are in excess of $1 million dollars. One injury occurred as a person was struck by flying debris.

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

The warnings

0 minutes of warning. NWS OKX issued a tornado warning for this county at 12:28 UTC, 0 minutes before the tornado touched down, in force until 13:30 UTC.

Issued (UTC)ExpiredProductOffice
12:08 UTC12:55 UTCSevere Thunderstorm WarningOKX
12:28 UTC13:30 UTCTornado WarningOKX

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 Slight Risk. The outlook in force was issued at 05:42 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), 12:00Z

0.5 hours before the tornado, 34 km from the path. August 8, 1999.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 12:00Z on 1999-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 1164 joules per kilogram, CIN -26, lifted condensation level 747 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 1999-08-08The 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 153 square meters per square second, 0 to 6 km bulk shear 41 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
1164 J/kg
Mixed-layer CIN
-26 J/kg
Surface CAPE
1568 J/kg
Mixed-layer LCL
747 m above ground
0-6 km bulk shear
41 kt
0-1 km bulk shear
21 kt
0-1 km storm-relative helicity
153 m²/s²
0-3 km storm-relative helicity
177 m²/s²
Significant tornado parameter
0.8
Supercell composite
5.3
0-3 km lapse rate
6.4 K/km

Open this sounding in Storm Lab

Brookhaven, NY (KOKX), 00:00Z

11.5 hours after it, 34 km from the path. August 9, 1999.

Skew-T log-pSkew-T log-p diagram, Brookhaven, NY at 00:00Z on 1999-08-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 336 joules per kilogram, CIN -36, lifted condensation level 1137 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 1999-08-09The 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 26 square meters per square second, 0 to 6 km bulk shear 38 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
336 J/kg
Mixed-layer CIN
-36 J/kg
Surface CAPE
1033 J/kg
Mixed-layer LCL
1137 m above ground
0-6 km bulk shear
38 kt
0-1 km bulk shear
19 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
95 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7
0-3 km lapse rate
6.3 K/km

Open this sounding in Storm Lab

The radar

The Brookhaven radar (KOKX), 34 km away, was scanning. The volume nearest the touchdown began at 12:26 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.

This ground now

The live radar over the trackEvery 1999 tornado in New YorkEvery tornado in New York since 1950Warnings in force in New York nowThe forecast where you are

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.