Tuesday May 15, 2018
Supercell Outbreak - Saugerties EF1 Tornado
(Severe weather locally limited to Ulster, Dutchess, southern Columbia and Litchfield counties)

Albany Doppler radar base reflectivity image at 2:53pm Tuesday May 15, 2018: Tornado warned supercell thunderstorm over southern Columbia County.

Tornado warned supercell thunderstorm over southern Columbia County, May 15, 2018


A series of violent rotating thunderstorms (supercells) produced giant hail up to 2.75" in diameter (baseball sized,) damaging straight line wind gusts in excess of 90 mph and one tornado within a narrow axis locally which stretched from northern Delaware County through northern Ulster, southern Columbia, northern Dutchess, southern Berkshire, and northern Litchfield counties between 1:30 and 3:30pm. These storms ultimately merged and consolidated into a damaging line which went on to produce additional significant wind damage and tornadoes further south through central and southern Ulster and through much of Dutchess counties locally with significant severe weather across southern Massachusetts and Connecticut to the east, and across northern and eastern Pennsylvania and northern New Jersey to the west and south. It was a major outbreak which included 9 confirmed tornadoes, one in Wayne County Pennsylvania with four in southeast New York, with three of those occurring in Orange and Putnam counties plus an EF1 that moved from Woodstock through Saugerties in northern Ulster county lifting just east of the Hudson river in Tivoli in northwest Dutchess County. In Connecticut there were four tornadoes, two in northeast Litchfield County (spawned from the Saugerties supercell) and two in New Haven County. In addition to the nine tornadoes, the outbreak resulted in 478 severe wind reports and 131 reports of hail greater than one inch in diameter. Five fatalities were reported as a result of the storms in the Northeast with none of those occurring in the CBS6 coverage area.

Saugerties Tornado Report from the Albany National Weather Service Storm Damage Assessment

TORNADO REPORT

RATING: EF1: Max winds to 90 mph (ALB NWS indicates most of the damage along the path was EF0)

LOCATION: Woodstock to Saugerties to Tivoli

TIME: 2:20pm TO 2:35pm Tuesday May 15, 2018

MAX PATH WIDTH: Approximately 528 Feet

PATH LENGTH: 5 Miles

Notes from ALB NWS: The storm that produced the tornado also produced at least one microburst with winds up to 90 mph which sheared and uprooted many large trees and sheared a few power poles. Most of the damage was indirect from trees falling on homes and other structures as well as power lines.

Albany NWS Tornado Path Map

Tornado warned supercell thunderstorm over southern Columbia County, May 15, 2018

SET UP
A warm frontal passage during the morning put the region into a warm and humid air mass where dewpoints climbed into the mid 60s through the early afternoon with temperatures in the Capital Region peaking out in the mid and upper 70s. Much hotter conditions, however, developed in the mid Hudson valley with highs ranging from the mid to upper 80s. Strong wind fields aloft were in place with bulk shear values over 70 knots along with a plume of steep mid level lapse rates which supported upward moving air. Thunderstorm triggers aloft included a mid level jet core as well as a modest mid level short wave trough. At the surface triggers included an inbound cold front as well as an outflow boundary which was generated by a batch of downpours and rumbles which moved from west to east across most of the local area north of the mid Hudson valley during the mid to late morning.

That morning round of non-severe convection effectively stabilized the atmosphere in and around the Capital Region to a point where there was insufficient time for recovery before the fast afternoon arrival of clouds and the cold front which effectively shut down the potential thunderstorms across most of the local area.

However, with significant heating and moisture pooling maximized in the mid Hudson valley along and south of the outflow boundary which set-up across Delaware, northern Ulster, southern Columbia and southern Berkshire counties, the stage was set for explosive thunderstorm development in that region in an environment of 1500 to 2000 j/kg of CAPE (convective available potential energy, or thunderstorm fuel.) A tornado watch was issued for most of the region around 1:00pm due to the developing conditions. However, at approximately 3:30pm all counties except Greene, Columbia, Berkshire, Dutchess, Ulster and Litchfield counties were dropped from the watch when it was absolutely clear that no severe weather would develop north of the outflow boundary.

Initial Tornado Watch area, Tuesday May 15, 2018


Between 1pm and 1:30pm a discreet strong thunderstorm developed in Delaware County which would become the first supercell of the day, forming in an environment of backed low level flow which increased the turning of the wind with height allowing rotation in the storm to develop. This storm would be the first locally to intensify and move east producing severe weather along its path across northern Ulster, southern Greene (large hail) southern Columbia, northern Dutchess, southern Berkshire and northern Litchfield counties. This would also be the storm that went on to produce the Woodstock to Saugerties EF0 to EF1 tornado along with hail up to 2.75" in diameter (baseball sized) and damaging straight line wind in excess of 90 mph. The cell did split with a second storm forming and intensifying to its north into Greene County. This cell also went on to produce hail in Greene and northern Columbia counties but ultimately weakened as its inflow was disrupted by the large storms to its south. With convection to the north essentially shut down, the main axis of severe weather initiated and traveled along the outflow boundary with several storms rolling over the same communities across northern Ulster, southern Columbia, northern Dutchess, southern Berkshire and northern Litchfield counties through 3:30pm before storms from Pennsylvania and these merged into a major severe weather producing complex which traveled south into the mid Atlantic and east into southern New England.

Albany Doppler Radar Base Reflectivity: Approximately 2:33pm. First supercell over Saugerties at the time a tornado was in progress.
Tornado, large hail, and damaging straight line wind producing supercell over Saugerties, May 15, 2018

Albany Doppler radar base reflectivity image at approximately 3:02pm: Second supercell thunderstorm rolling through Saugerties, training along the outflow boundary just behind the first damaging storm. 1.30" of rain was measured by our WeatherNet 6 spotter in Saugerties, falling in short intervals from the two storms, which produced brief but significant urban and poor drainage flooding. Rainfall was intense to accumulate to this level considering the very fast 50-55 mph forward speed of the storms.

Second supercell over Saugerties, NY Tuesday May 15, 2018

Albany National Weather Service Straight Line Wind Damage (Macroburst) Report
I-84 Corridor in southern Dutchess County

Locations Impacted: Beacon/Wappingers Falls to East Fishkill/Hopewell Junction

EVENT: Macroburst (Large zone of straight line downdraft winds)

WIND INTENSITY: Ranged from 85 to 105 mph

PATH WIDTH: 3 Miles

PATH LENGTH: 8 Miles

ESTIMATE TIME: 4:20PM

Albany NWS Notes: The macroburst toppled/uprooted hundreds of trees. Some trees fell on structures with limited direct damage to structures due to the wind including a fallen chimney along with some siding torn off a few homes

Giant Hail in Clermont, Columbia County, Tuesday May 15, 2018 - Photograph contributed by Jenn Jordan Griffin via Facebook

Giant Hail in Clermont, Columbia County, Tuesday May 15, 2018 

Giant Hail in Canaan, CT, Litchfield County, Tuesday May 15, 2018 - Photograph by Sean Organ

Giant Hail in Canaan, CT, Litchfield County, Tuesday May 15, 2018 

Storm Prediction Center Storm Reports Graphic for Tuesday May 15, 2018 showing the locations of reported severe wind, wind damage, large hail, and tornadoes

Storm Reports for Tuesday May 15, 2018 


NWS Storm Reports for Tuesday May 15, 2018. Note, these reports are used to verify the NWS warnings which were issued for this event and therefore do not necessarily represent an accounting for all of the wind damage which may have occurred.

Town County Severe Weather Report Time
4 Miles NE of Woodstock Ulster Tree and wires blown down on Route 212 at Pine Lane blocking both lanes 2:25pm
1 Mile WNW of Saugerties Ulster EF1 Tornado: Maximum winds to 90 mph, traveled from Woodstock through Saugerties, lifting in Tivoli between 2:29pm and 2:35pm, 90 mph hour downburst also occurred, hundreds of trees down, some on houses 2:29pm
Germantown Columbia Tree and wires blown down on Viewmont Road 2:45pm
2 Miles SSW of Clermont Columbia 2.75" diameter hail (baseball sized) 2:45pm
4 Miles WNW of Saugerties Ulster Trees down blocking the southbound exit ramp of I-87 2:45pm
2 Miles ESE of Clermont Columbia Large tree blown down on wires 2:46pm
Woodstock Ulster 1.00" diameter hail (quarter sized), lasted 3-4 minutes 2:48pm
2 Miles E. of Clermont Columbia 1.75" diameter hail, (golf ball sized) 2:54pm
3 Miles SE of Niverville Columbia 1.50" diameter hail, (ping pong ball sized) 2:54pm
4 Miles ENE of Elizaville Columbia 2.00" diameter hail, car windows shattered on the Taconic State Parkway near the Gallatin Overlook 2:57pm
4 Miles SE of Livingston Columbia 2.00" diameter hail 3:00pm
3 Miles W. of Saugerties Ulster 1.00" diameter hail 3:00pm
Copake Columbia 1.00" diameter hail 3:05pm
2 Miles E. of Claryville Columbia 0.75" diameter hail 3:08pm
2 Miles E. of Claryville Columbia 0.75" diameter hail 3:08pm
2 Miles NE of Copake Columbia 0.88" diameter hail 3:10pm
Ancram Columbia 1.50" diameter hail 3:10pm
2 Miles SSW of Clermont Columbia Estimated 2.00" diameter hail 3:11pm
1 Mile N. of Canaan, CT Litchfield 1.50" diameter hail 3:13pm
4 Miles ENE of Elizaville Columbia 1.50" diameter hail, damage to cars 3:23pm
Elizaville Columbia 1.75" diameter hail, hail broke windows 3:23pm
1 Miles NW of Rosendale Ulster 0.90" diameter hail 3:30pm
Stone Ridge Ulster Wind Damage: Two trees blown down, also 1/2" diameter hail 3:31pm
Norfolk and Falls Village, CT Litchfield Wind damage, trees and wires blown down 3:33pm to 3:36pm
Livingston Columbia 2.00" diameter hail 3:40pm
Falls Village, CT Litchfield 1.75" diameter hail 3:41pm
Rosendale Village Ulster 1.00 diameter hail 3:41pm
Winsted, CT So. Litchfield EF1 Tornado - Estimated maximum winds of 95 mph 3:44pm
Winsted and New Hartford, CT So. Litchfield Wind damage, trees and wires down, 1.50" diameter hail 3:45pm to 4:00pm
Shawangunk Ulster Wind damage, trees blown down 4:00pm
4 Miles SE of Phoenicia Ulster 1.75" diameter hail 4:01pm
2 Miles NE of Beacon Dutchess Measured 78 mph wind gust 4:20pm
Wappingers Falls/Beacon to East Fishkill/Hopewell Junction Dutchess 85 mph to 105 mph macroburst downed hundreds of trees along an 8 mile path, 3 miles wide 4:20pm to 4:30pm
1 Mile E. of Shawangunk Ulster Trees and wires blown down 4:25pm
1 Mile NNE of Fish Kill through Fish Kill to Hopewell Junction Dutchess Large trees and wires down, damage to roof shingles, trees down on the Taconic State Parkway northbound lane 4:25pm-4:30pm
4 Miles SSW of New Milford, CT Litchfield Shingles torn off the roof of New Milford High School 4:50pm

WeatherNet 6 Storm Total Rainfall Reports - Tuesday May 15, 2018
(Rainfall is a daily total including rain from morning showers and rumbles)

Town
County
Rainfall Report
Town
County
Rainfall Report
Clarksburg, MA Berkshire 0.17" Canaan, CT Litchfield 1.10"
Becket, MA Berkshire 1.50"      
           
Glenmont Albany 0.25" Westmere Albany 0.25"
           
Taghkanic Columbia 1.50" Livingston Columbia 1.16"
Chatham Columbia 0.50" Ancramdale Columbia 1.25"
           
Arkville Delaware 1.20" Denver Delaware 1.00"
Margaretville Delaware 1.14" Roxbury Delaware 0.61"
           
Red Hook Dutchess 0.97" Poughkeepsie Dutchess 1.17"
           
Broadalbin Fulton 0.30" Perth Fulton 0.21"
Fish House Fulton 0.12"      
           
West Kill Greene 0.45" Cairo Greene 0.90"
Halcott Greene 0.39" Catskill Greene 0.25"
Greenville Greene 0.25"      
           
Wells Hamilton 0.24" Indian Lake Hamilton 1.00"
           
Amsterdam Montgomery 0.25" Fonda Montgomery 0.24"
Palatine Bridge Montgomery 0.15" Tribes Hill Montgomery 0.10"
           
Oneonta Otsego 0.20" to 0.28"      
           
Center Brunswick Rensselaer 0.21" Petersburg Rensselaer 0.39"
Speigletown Rensselaer 0.20"      
           
Saratoga Springs Saratoga 0.17" Galway Saratoga 0.22"
Lake Desolation Saratoga 0.18"      
           
Charlotteville Schoharie 0.30" Warnerville Schoharie 0.30"
Richmondville Schoharie 0.35" North Blenheim Schoharie 0.22"
           
Whiteport Ulster 0.75" Phoenicia Ulster 0.49"
Ulster Park Ulster 1.50" Saugerties Ulster 1.30"
Esopus Ulster 1.46" West Shokan Ulster 0.78"
           
Lake Luzerne Warren 0.10"      
           
Hebron Washington 0.15" Hudson Falls Washington 0.04"
           
Landgrove, VT Bennington 0.12" Woodford, VT Bennington 0.26"
West Arlington, VT Bennington 0.14" West Rutland, VT Rutland 0.17"