Major Severe Thunderstorm and Tornado Outbreak, Sunday May 31, 1998
Violent F-3 Mechanicville-Stillwater Tornado


Reanalyzed March 25, 2016
Steve LaPointe
CBS6 Chief Meteorologist


Like a bomb went off, that's how the damage in the Viall Hill neighborhood in Stillwater (shown below) and surrounding areas was described after a fast moving violent tornado plowed through around 4:30pm on Sunday, May 31, 1998.

Newspaper photograph of the devastated Vial Hill area of Stillwater, June 1, 1998

The tornado was part of an almost unprecedented outbreak, in terms of areal coverage and duration, of severe thunderstorms and tornadoes throughout the Northeast which spanned from the mid afternoon through the early nighttime hours with multiple waves of violent storms moving across eastern New York and western New England. In total, twenty five tornadoes touched down in New York, Pennsylvania, Vermont, Connecticut and New Hampshire with nine of them in New York. For perspective, ten tornadoes, mostly brief weak ones, will touch down in New York during an entire average severe weather season. Additionally almost 180 reports of damaging straight line wind and just under forty reports of large damaging hail were recorded for the event, a number which only captures what was specifically reported for the purposes of National Weather Service warning verification, and does not necessarily represent all of the damaging wind and hail events which may have occurred. The graphic below highlights the distribution of severe weather reports for the outbreak.

Severe Wind, hail, and tornado reports for the May 31, 1998 Outbreak

The long track Mechanicville-Stillwater tornado, which went on to produce damage in Schaghticoke in Rensselaer County as well as in Bennington, VT, as well as the long track track tornado which went through Binghamton, were both rated violent at an F-3 intensity. Today's ranking would have the storm classified as an EF-3 on the enhanced fujita tornado intensity scale, with winds ranging from 136 to 165 mph.

(The EF scale was introduced on February 1, 2007 after studies showed it took winds of lower velocities than had earlier been thought to produce the types of damage observed with tornadoes. All historical tornadoes retain their rankings but have the associated lower velocities attached to them vs. what the original fujita tornado intensity scale had assigned. )

Damage from the storms was widespread throughout the local area with 60,000 Capital Region customers left without electricity and up to 150,000 without electricity regionally. Many areas remained in the dark for up to four days after the outbreak due to the extensive damage to major transmission line infrastructure. Damage was estimated to be from 65-70 million dollars in the Capital Region, mostly from the Mechanicville tornado. Fortunately, and perhaps as a by product of superior warnings by the Albany National Weather Service and Capital Region media outlets, no fatalities occurred in eastern New York or western New England as a direct result of the storms.

The Meteorology and Timeline
A strong cold front responsible for a widespread severe weather producing squall line across eastern New York and western New England on Friday, May 29, moved south of the region and stalled over southern Pennsylvania on Saturday, May 30. A weak bubble of Canadian high pressure, associated with very dry air, moved over New York and New England producing a beautiful Saturday weather wise. Dewpoint temperatures dropped from the muggy 60's on Friday into the upper 30's on Saturday with mostly clear skies.

Meanwhile, in South Dakota, a powerful westerly jet stream flow up to 150 mph above 30,000 feet contributed to a devastating tornado outbreak which resulted in the almost complete destruction of the town of Spencer. It was the most destructive tornado in South Dakota's history and second deadliest with six fatalities reported. The low pressure system responsible for the Spencer tornado had intensified and raced east to northern Michigan by 8:00 am Sunday morning, May 31. The counterclockwise flow around the cyclone pulled the stalled front over southern Pennsylvania north into the Berkshires through the early afternoon. Very warm humid air was now clashing with the cooler dry air over the Berkshires, resulting in an early round of several large, locally damaging thunderstorms which produced heavy rain, frequent lightning, and isolated damaging downburst winds along the warm front. Simultaneously, in the low pressure system's warm sector, a derecho (a highly organized complex of severe thunderstorms which produce widespread wind damage over long distances) was moving across eastern Michigan. The derecho produced convective wind gusts up to 100 mph across Michigan as well as isolated tornadoes. The first of what would be several tornado watch areas was issued early in the morning for much of western and northern New York to cover the severe weather threat with this derecho as it raced through Canada and moved into New York.

8am surface analysis - Intense low pressure with central pressure down to 992 mb (very strong for late May) was tracking north of the region dragging the convectively active warm front across the region.

8am Surface Analysis, May 31, 1998 

11am surface analysis - showing the eastward progress of the strong warm front through eastern New York. The Michigan derecho was in the process of moving into western New York at this time.

11am Surface Analysis, May 31, 1998

With western and northern New York under an early morning meteorological gun with strong and severe thunderstorms, sunshine was simultaneously breaking out across eastern New York and western New England with dewpoint temperatures rising quickly with the passage of the warm front. By early Sunday afternoon the dewpoint temperatures had reached sultry readings in the upper 60s and air temperatures had climbed into the 70s and low 80s. CAPE values (convective available potential energy) were in the process of climbing to a range of 2000 to 4000j/kg with a notable elevated mixed layer moving into the region behind the warm front. (An elevated mixed layer (EML) is a layer of warm dry air aloft which acts to cap or prevent thunderstorm development until a combination of upper level cooling and surface warming erodes the cap allowing for explosive development to occur. EML's are often a necessary ingredient for widespread violent severe weather outbreaks.

At the surface, winds increased from the south-southeast up to 30 mph in response to the strong low passing to the region's north. Upper air winds increased from the west to between 40 and 80 mph between the 5000' to 20,000' levels. The dramatic change in wind direction and speed with height created a highly wind sheared environment favorable for developing violent supercell thunderstorms (storms with rotating updrafts.)

Adding further to the favorable environment for violent thunderstorms was the configuration of two jet stream segments at the 30,000' to 40,000' levels. A powerful 100 to 150 mph jet streak stretched from the Great Lakes into the Ohio and Tennessee valleys putting the Northeast in its left exit region, or a region of strong atmospheric lift. A second powerful jet streak of 100 to 150 mph arched from NW to SE from Quebec to Maine, putting the Northeast in its right entrance region, also an area of strong lift. The combined effects of the diffluent flow aloft from this jet configuration over the capped highly unstable and strongly wind sheared environment set the stage for the widespread outbreak of tornadic thunderstorms. All that was needed was the trigger to set it all off.

By 1pm the initial line of severe thunderstorms (the Michigan derecho) was weakening, but still producing damaging straight line wind, as it moved into the western Adirondacks. The main tornado event triggered along the derecho's outflow boundary (a zone of rain cooled air, almost a mini cold front) which sagged south into the Mohawk valley and Capital Region.  The outflow zone acted as a convergence boundary which coupled with cooling aloft zipped open the cap and initiated the first round of violent afternoon storms and the supercell that went on to produce the Mechanicville-Stillwater tornado.  A PDS (particularly dangerous situation) tornado watch was issued by 2:30pm for all of eastern New York and western New England as the storms began erupting.

The first tornadic supercell formed on the outflow boundary in Montgomery County around 3:30pm. This storm rapidly intensified near Amsterdam and moved east at 50mph into Saratoga county producing the devastating tornado which moved through Mechanicville and Stillwater
. A tornado warning for Saratoga County was issued by the Albany NWS at 3:43pm. The tornado began doing damage on Usher's Road in Halfmoon at 4:20pm, racing into Mechanicville and Stillwater at its peak intensity through 4:30pm, then continued through Schaghticoke along Route 67 and into Bennington, VT finally dissipating over Shaftsbury, VT with the last of the damage occurring on Lower East Road at 5pm.

By 4:30pm, other rotating severe thunderstorms had explosively developed throughout the region with many areas being affected by frequent lightning, high wind, hail, and torrential rain. At 4:40 pm a second tornado (F-1 intensity) developed from a supercell at the Albany airport. A peak wind gust of 82 mph was recorded with the passage of that storm at 4:40pm with damage into the town of Colonie. From 3:30 pm to 7:00 pm almost every county in the WRGB coverage area in New York and New England experienced severe weather in the form of large hail, damaging straight line winds or tornadoes.


Albany airport weather observation at 4:46pm May 31, 1998

ALB SP 2046 AO2A 1 SCT 21 SCT E33 OVC 1/2TORNADO TR 68/63/2712G71/958/ WND 25V32 FUNNEL CLOUD B45 PK WND 32071/2040 TSB17RAB17 PRESRR FRQ LTGCG OHD TS OHD MOV E PCPN 0040=


Decoded
Albany special observation 4:46pm EDT
Cloud height information: scattered clouds at 100', 2100' and an estimated 3300' cloud base overcast
1/2 mile visibility, rain/thunderstorm with tornado in progress
Temperature: 68°
Dewpoint: 63°
Wind westerly at 12 knots, gusting to 71 knots
Altimeter: 29.58"
Funnel cloud began 45 minutes after the hour
Peak wind from the northwest at 71 knots at 4:40pm
Thunderstorm and rain began at 17 minutes after the hour
Pressure rising rapidly
Frequent lightning, cloud to ground overhead
Thunderstorm overhead moving to the east
0.40" of precipitation

Albany airport weather observation at 4:58pm, May 31, 1998

ALB SP 2058 A02A 1 SCT E24 OVC 1TRF 64/63/2219G60/963/ FUNNEL CLOUD E57 WSHFT 2042 PRESRR PCPN 0000=

Decoded
Albany special observation 4:58pm EDT
Cloud height information: scattered clouds at 100' and an estimated 2500 cloud base overcast
1 mile visibility, rain, thunderstorm, fog
Temperature: 64°
Dewpoint: 63°
Wind SW at 19knots, gusting to 60 knots
Altimeter: 29.63"
Funnel cloud ended at 57 minutes after the hour
Pressure rising rapidly


A short break from the violent weather developed in the Capital Region and western New England during the late afternoon and early evening before a second round of severe thunderstorms and tornadoes moved into the region from the west. The second round of storms produced more violent lightning and damaging straight line winds throughout the region including a tornado (F-2 Rating) which began doing damage on Palmer Road in East Schodack at approximately 7:15pm with the tornado lifting just east of Millers Corners in the town of Nassau. The NWS later determined that in addition to the tornadoes, widespread and significant damage from 50-80 mph straight line winds had occurred in Herkimer, Fulton, Montgomery, Schoharie, Greene, and Ulster counties.

The entire severe event finally ended locally by 10:30 pm with the passage of the cold front.

8pm surface analysis - showing the advancing cold front and pre-frontal trough as well as an intense 988 mb low over SE Canada. The cold front moved east of the region by 11pm ending the severe weather outbreak.

8pm Surface Analysis, May 31, 1998

The Albany National Weather Service issued approximately forty six severe weather warnings for eastern New York and western New England, most of them tornado warnings, the most tornado warnings the Albany National Weather Service forecast office had issued for a single event to date. Doppler radar indicated rotation in most of the storms which formed and moved across the local area, certainly a very rare type of severe weather outbreak for this part of the country. What was even more rare was the initial "High Risk" severe weather outlook from the Storm Prediction Center. It was the first and only (to date) "High Risk" ever issued in the Northeast.

Mechanicville-Stillwater Tornado Aftermath Photographs (Photographs by Steve LaPointe)

Click Here For the Full Gallery of Storm Damage Photographs

Tornado winds of up to165 mph produced extensive damage to the Viall Hill section of Mechanicville and Stillwater on May 31, 1998.  The photographs show the damage in the Viall Hill area as well as the Route 4/32 area.

The roof and many interior walls blown out of this home with the front lawn littered with debris from other homes

This structure was declared a complete loss with the roof and much of the second floor missing.

This home was in the direct path of the tornado and was completely destroyed.   Meteorologist survey tornado damage to rank the intensity of the storm.   Damage of the magnitude shown in this photograph indicates and F-3 borderline F-4 tornado on the Fujita tornado intensity scale.

Trees adjacent to this home were twisted apart and stripped of their foliage. An automobile was thrown through the air landing at the base of the trees in a pile of debris.

Only a shell remained of this structure with the roof gone and windows and walls blown out.

Winds of 165 mph stripped this home completely from its foundation reducing it and it's contents to debris.

Considerable damage occurred to these buildings facing the Hudson river as the tornado moved towards Rensselaer county.

This Ford Taurus was lifted and thrown several hundred yards landing in this yard.

This small section of the Viall Hill neighborhood was ground zero with the complete destruction of trees and several homes.

 

The table lists the tornado and damage reports, collected by WRGB and the National Weather Service, for the counties in the WRGB coverage area for this outbreak.

Town

County

State

Storm Report

Estimated Time

Fonda Montgomery NY Wind damage, Trees down 3:42 pm
Mohawk Herkimer NY Tornado on Showmaker Hill Road 3:45 pm
Milton Center Saratoga NY One inch diameter hail 4:15 pm
Stillwater Saratoga NY Major Tornado, massive destruction 4:20 pm
Mechanicville Saratoga NY Major Tornado 4:20 pm
Saratoga Springs Saratoga NY 1.75" diameter hail 4:20 pm
Cooperstown Otsego NY Wind damage 4:20 pm
Laurens Otsego NY Wind damage 4:20 pm
S. Washington County Washington NY Tornado 4:28 pm
N. Adams Berkshire MA Wind damage, 55 mph winds at airport 4:28 pm
Middleburgh Schoharie NY Wind damage, 60 mph wind gust 4:32 pm
Bethlehem Center Albany NY Wind damage 4:38 pm
Albany Airport Albany NY 82 mph wind gust and an F-1 Tornado 4:40 pm
Bennington Bennington VT Wind damage, Trees and wires down 4:45 pm
Colonie Albany NY Wind damage, Trees and wires down 4:50 pm
Schaghticoke Rensselaer NY Tornado 4:50 pm
Stuyvesant Columbia NY Wind damage, trees down 5:10 pm
Chatham Columbia NY .75" diameter hail 5:10 pm
Kinderhook Columbia NY Wind damage, trees down 5:10 pm
Pittsfield Berkshire MA Wall cloud and tornado over airport 5:27 pm
Stuyvesant Columbia NY Once inch diameter hail 5:31 pm
Nassau Rensselaer NY Wind damage 5:35 pm
Pittsfield Berkshire MA One inch diameter hail 5:45 pm
Unadilla Otsego NY Tornado 5:52 pm
Hartwick Otsego NY Wind damage, numerous trees down 6:22 pm
Milford Otsego NY F-2 Tornado, roofs blown off homes 6:22 pm
Mohawk Herkimer NY Wind damage, trees and power lines down 6:25 pm
Clarksville Albany NY Wind damage 6:30 pm
New Scotland Albany NY Wind damage 6:40 pm
Little Falls Herkimer NY Tornado 6:41 pm
Breakabeen Schoharie NY Wind damage, trees down 6:47 pm
Mechanicville Saratoga NY Wind damage 7:08 pm
Duanesburg Schenectady NY Wind damage, trees down 7:15 pm
East Schodack to Nassau Columbia NY Tornado 7:15 pm
Guilderland Center Albany NY Tornado 7:16 pm
Selkirk Albany NY Tornado, damage to industrial buildings 7:35 pm
Schoharie County Schoharie NY Wind damage county wide 7:35 pm
Greenwich Washington NY Wind damage 7:35 pm
Stephentown Rensselaer NY .75" diameter hail (Dime size) 7:42 pm
North Adams Berkshire MA 70 mph wind gust observed 7:55 pm
Great Barrington Berkshire MA .75" inch diameter hail 8:00 pm
Saugerties Ulster NY Wind damage 8:00 pm
Pittsfield Berkshire MA Tornado near Franklin Street 8:03 pm
Cairo Greene NY Tornado 8:15 pm
Catskill Greene NY .75" inch diameter hail 8:23 pm
Catskill Greene NY Tornado 8:24 pm
Pownal Bennington VT Wind damage 8:40 pm
Medusa Albany NY Wind damage 9:15 pm
Rhinebeck Dutchess NY Widespread wind damage 9:30 pm
New Milford Litchfield CT Wind damage, trees down 9:50 pm