A significant severe weather outbreak developed across central New York as a storm system moved east from the Great Lakes.  First, showers and thunderstorms developed early in the evening on the 27th, as an upper level disturbance approached the region. Two of the more significant storms included one supercell that produced a tornado in Steuben county, and a bowing line segment that caused tree and structural damage across Steuben, Chemung and Schuyler counties. Elsewhere across central New York, storms caused scattered wind damage and heavy rain.
After a brief break in the late evening, mini super cells developed overnight ahead of a cold front. Several tornadoes and severe thunderstorms developed between about 1:30 a.m. and 6 a.m., with many reports of damage. Most of the tornadoes were EF1 and EF2. Significant flash flooding also transpired during the overnight hours.

Thunderstorm Wind in SULLIVAN, NEW YORK
From 28-APR-11 09:35:00 to 28-APR-11 09:35:00 (EST-5)
Location: GRAHAMSVILLE
Magnitude: 50.00 EG
Property damage: 1.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A tree was blown down.

Thunderstorm Wind in OTSEGO, NEW YORK
From 28-APR-11 04:40:00 to 28-APR-11 04:40:00 (EST-5)
Location: WEST ONEONTA
Magnitude: 60.00 EG
Property damage: 8.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Widely scattered trees were snapped and uprooted.

Flash Flood in TIOGA, NEW YORK
From 28-APR-11 03:00:00 to 28-APR-11 12:00:00 (EST-5)
Location: LITCHFIELD
Flood cause: Heavy Rain
Property damage: 3.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Major flash flooding occurred in several areas of the county during the overnight hours on the 28th, especially along the State Route 38 corridor.  The town of Owego had 1.5 million in damages to roads, five major stream crossings, ditches, culverts and road shoulders.  The Town of Newark Valley had $800,000 in damages, including 50 homes that were impacted, as well as road washouts and closures. Schools were closed in the town due to impassable roads.

Thunderstorm Wind in CHENANGO, NEW YORK
From 28-APR-11 03:00:00 to 28-APR-11 03:00:00 (EST-5)
Location: MC DONOUGH
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A significant swath of trees were blown down on Waldron Road.  These trees were all pointing to the southeast in a slightly divergent pattern.  This damage occurred simultaneously with a tornado track just to the east.

Thunderstorm Wind in BROOME, NEW YORK
From 28-APR-11 03:55:00 to 28-APR-11 04:00:00 (EST-5)
Location: CONKLIN
Magnitude: 50.00 EG
Property damage: 15.00K
Crop damage: 0.00K
Reported by: Newspaper

Trees were blown down in Conklin and the town of Binghamton.  Trees fell on a house in Conklin.

Thunderstorm Wind in TOMPKINS, NEW YORK
From 28-APR-11 00:45:00 to 28-APR-11 00:45:00 (EST-5)
Location: DANBY
Magnitude: 87.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

Straight line winds of nearly 100 mph produced significant tree damage. Trees fell on the roof of a house.  A home sustained significant damage as the roof was peeled up and strewn 30 yards.  Minor siding damage occurred to other houses nearby.  Hail (unknown size) also pummeled homes and cars.

Flash Flood in DELAWARE, NEW YORK
From 28-APR-11 09:00:00 to 28-APR-11 15:00:00 (EST-5)
Location: HALE EDDY
Flood cause: Heavy Rain
Property damage: 650.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Heavy rain caused flash flooding and damage to roads and culverts and storm drain systems.  Some of the harder hit areas included Hamden which experienced Bridge damage,  and the town of Deposit.

Flash Flood in CHEMUNG, NEW YORK
From 27-APR-11 21:00:00 to 28-APR-11 03:00:00 (EST-5)
Location: WAVERLY
Flood cause: Heavy Rain
Property damage: 400.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Several towns and villages experienced damage to roads and culverts due to heavy rain and flash flooding.  The town of Erin and Village of Millport both reported severe damage to roads and the highway system.  Damage was also reported in The towns of Ashland, Baldwin and City of Elmira.

Flash Flood in CHENANGO, NEW YORK
From 28-APR-11 04:07:00 to 28-APR-11 15:30:00 (EST-5)
Location: LAMBS CORNERS
Flood cause: Heavy Rain
Property damage: 500.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Chenango county experienced the majority of its flooding from a small stream.  About 40 structures were flooded county-wide, with most of those from the Canasawacta Creek at the Norwich city line coming out of its banks.  The creek, according to the IFLOWS stream gage operated by the City of Norwich, rose over 10 feet in under one hour during the morning of the 28th.  One privately owned bridge was lost along the creek.  The river stage at this point was of an equivalent magnitude as the June, 2006 regional flood of record, and well into the major flood category at this location.  Other roads in the county outside of the Norwich area were impacted, including one that was totally torn up and post flood resembled a stream bed.

Thunderstorm Wind in CHENANGO, NEW YORK
From 28-APR-11 04:13:00 to 28-APR-11 04:13:00 (EST-5)
Location: AFTON
Magnitude: 83.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A significant downburst wind event hit the Afton area.  Much of the damage was done to trees along the core path of the downburst, with scattered tree damage north and south of the core.  The majority of trees fell to the east-northeast, with a slightly divergent pattern detected.  Damage occurred to several homes from trees falling on the structures.  The heaviest damage occurred near power lines north of the intersection of Algerine Street and Route 7.  The path of tree damage was seen crossing Interstate 88, with uprooted and snapped trees.

Hail in CORTLAND, NEW YORK
From 27-APR-11 20:23:00 to 27-APR-11 20:23:00 (EST-5)
Location: CORTLAND
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm Wind in TOMPKINS, NEW YORK
From 28-APR-11 00:48:00 to 28-APR-11 00:48:00 (EST-5)
Location: ITHACA
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Trees were snapped off near the Ithaca/Danby town line, south of Ithaca College.

Thunderstorm Wind in STEUBEN, NEW YORK
From 27-APR-11 19:06:00 to 27-APR-11 19:10:00 (EST-5)
Location: PAINTED POST
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Large tree limbs were broken in the Painted Post area.

Flash Flood in BROOME, NEW YORK
From 28-APR-11 05:00:00 to 28-APR-11 12:00:00 (EST-5)
Location: TRACY CREEK
Flood cause: Heavy Rain
Property damage: 4.00M
Crop damage: 0.00K
Reported by: Emergency Manager

Broome county experienced significant flash flooding, especially along the route 26 corridor.  Route 26 was closed between Glen Aubrey and Whitney Point, with 18 houses cut off by flood waters.  Nanticoke Creek in the town of Maine flooded many homes, with water up to the first floor of some homes.  The county reported 3.5 million in public sector damages, not including an additional 0.6 million for roadway damages to Interstate 81 in the Binghamton area or damages to about a dozen homes along Route 26.  Close to 150 people were evacuated and two shelters were set up.

Thunderstorm Wind in CHEMUNG, NEW YORK
From 27-APR-11 19:13:00 to 27-APR-11 19:20:00 (EST-5)
Location: BIG FLATS
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Trees were blown down in Big Flats, Horseheads and Alpine.

Thunderstorm Wind in SCHUYLER, NEW YORK
From 27-APR-11 19:25:00 to 27-APR-11 19:30:00 (EST-5)
Location: CATHARINE
Magnitude: 60.00 EG
Property damage: 60.00K
Crop damage: 0.00K
Reported by: Public

Severe straight line winds caused significant damage to a barn and power lines. Trees were also blown down just north of Odessa.

Flash Flood in YATES, NEW YORK
From 27-APR-11 20:00:00 to 28-APR-11 04:00:00 (EST-5)
Location: BELLONA
Flood cause: Heavy Rain
Property damage: 800.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A total of seven towns and one village reported significant roadway damages.  In most cases, the damages were related to either shoulder wash-outs or significant debris buildup on roadways.  In one case, the road was fully washed out.  several other roads had deep, newly formed pot holes/voids.  In addition to roadway damage, there were several cases of mass wasting and sediment transport.  In the Town of Middlesex, one home had soil and debris build-up as high as the door knob level.  Another area along South Lake Road had the downward movement of an entire portion of a hillside with localized water damages to several homes.  A voluntary evacuation was in place for the area along South Lake Road.  Some of the harder hit areas included Barrington, Benton, Italy, Jerusalem, Middlesex, and Penn Yan.

Thunderstorm Wind in SCHUYLER, NEW YORK
From 27-APR-11 19:32:00 to 27-APR-11 19:32:00 (EST-5)
Location: MONTOUR FALLS
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Several large trees were blown down.

Thunderstorm Wind in BROOME, NEW YORK
From 27-APR-11 20:55:00 to 27-APR-11 20:55:00 (EST-5)
Location: KATTLEVILLE
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Trees and power lines were blown down across Route 79.

Thunderstorm Wind in OTSEGO, NEW YORK
From 27-APR-11 21:45:00 to 27-APR-11 21:45:00 (EST-5)
Location: GILBERTSVILLE
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: County Official

Trees were blown down in Gilbertsville.

Thunderstorm Wind in CHENANGO, NEW YORK
From 27-APR-11 21:30:00 to 27-APR-11 21:30:00 (EST-5)
Location: NEW BERLIN
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: County Official

Trees were blown down in south New Berlin.

Thunderstorm Wind in STEUBEN, NEW YORK
From 27-APR-11 19:00:00 to 27-APR-11 19:00:00 (EST-5)
Location: CAMPBELL
Magnitude: 60.00 EG
Property damage: 6.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Trees were blown down.

Thunderstorm Wind in TIOGA, NEW YORK
From 28-APR-11 00:50:00 to 28-APR-11 00:50:00 (EST-5)
Location: SPENCER
Magnitude: 60.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Numerous trees were blown down.

Tornado in CHENANGO, NEW YORK
From 28-APR-11 03:58:00 to 28-APR-11 04:00:00 (EST-5)
Location: COLUMBUS
Tornado F-scale: EF1
Property damage: 50.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado path began about 3 miles to the northwest of Columbus, NY off Barnard Road. Damage was primarily to trees which were uprooted and snapped. The upper story of a two story horse barn was torn off. This was the only structure identified that was damaged by the tornado. Debris and trees were blown to the left of the path. The remaining damage was to trees along the 0.9 mile path. The tornado weakened to EF0 after the first mile then strengthened back briefly to EF1 after crossing Kelly Road. The tornado then weakened again to EF0 and lifted after crossing Pope Hill Road before reaching the Madison county line.

Tornado in CHEMUNG, NEW YORK
From 28-APR-11 00:23:00 to 28-APR-11 00:25:00 (EST-5)
Location: ERIN
Tornado F-scale: EF2
Property damage: 575.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado started just west of the Erin Town Hall, south of Route 223.  It began just southwest of the local cemetery and tracked toward the northeast. Numerous pine trees were snapped off and uprooted in the cemetery.
Immediately to the west of the cemetery, a well-constructed barn was destroyed, with all four walls completely collapsed. The tornado tracked northeast and across Route 223. The tornado lofted debris into the yard across the street with debris from the destroyed barn impaled into the front lawn.  Debris also blew all the windows out of the front of the home, with some debris penetrating the siding and thrown into the home. At this site, all three vehicles were damaged with a beam from the destroyed barn impaled through the dashboard of one vehicle.  An 11,000 pound camper was flipped up over a five foot fence and toppled onto its side before coming to rest.
The tornado continued tracking to the northeast with damage to a barn roof and debris wrapped in trees.  A garage and mobile home were completely destroyed.  Heavy debris from the mobile home was strewn approximately 100 yards downstream from the site, with lighter material found several miles away.
The tornado tracked an additional one-half mile up the hill with numerous trees uprooted or snapped and two horses killed on the farm.  At this point, the tornado lifted and no additional damage was found.

Tornado in TOMPKINS, NEW YORK
From 28-APR-11 00:41:00 to 28-APR-11 00:45:00 (EST-5)
Location: NEWFIELD SKYHOOK ARP
Tornado F-scale: EF1
Property damage: 125.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The tornado touched down in a forest off of Jersey Hill Road, northwest of the town of Danby.  Numerous pine trees were uprooted and snapped in this forest.  The tornado tracked from southwest to northeast, snapping numerous pines as it crossed Comfort Road.  A metal outbuilding was completely collapsed and a barn across the street received roof damage, with debris lofted into the trees.
The tornado continued off to the northeast toward the intersection of Beardsley Lane and Danby Road.  One home sustained damage when a tree collapsed onto the roof and a window was blown out.  Surrounding homes saw numerous trees snapped or uprooted.  A small branch was propelled and impaled into a car windshield.
A homeowner at the intersection of Beardsley Lane and Danby Road had a working anemometer at the time of the tornado.  At 1:44 am, a wind gust to 90.3 mph was recorded.  No additional tornado damage was noted as the storm headed off to the northeast.

Tornado in STEUBEN, NEW YORK
From 27-APR-11 19:04:00 to 27-APR-11 19:09:00 (EST-5)
Location: CAMPBELL
Tornado F-scale: EF1
Property damage: 150.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado first touched down on a hillside just west of Hough Road, in the town of Campbell. As the tornado topped the crest of the hill and descended towards Hough Road, dozens of trees were either snapped off or uprooted, in a swath about 150 yards wide. Included in this grove of trees were numerous large healthy hardwoods. As the tornado crossed Hough Road, it damaged two homes and a storage barn. The houses sustained mostly roof and siding damage, while the barn (actually bolted to a foundation) was moved off of its cement padding, with heavy damage to the roof and two of the walls, with its shingles blown westward back across Hough Road and into a field. A large camper was also blown cross-wise about 6 inches. Several large pine trees were uprooted on these properties, and facing northeastward. The tornado was estimated to be EF1 strength at this location.
Farther northeast, sporadic tree snaps and uproots were noted, until an area of heavier damage was once again seen near Tannery Road, just west of the Cohocton River. Once again, a swath of trees were either snapper or uprooted, just behind a residence southwest of Tannery Road. Again, many large healthy trees were included in this group, including some hardwoods, with a chaotic damage pattern noted. An EF1 rating was estimated at this location. The tornado appeared to have lifted for a brief time, with little damage noted to the residence itself.
A short distance further to the northeast, the storm crossed Interstate 86, just east of Exit 41. Several tree uproots and snaps occurred on either side of the highway, with two large trees uprooted in the highway median.
Just northeast of Interstate 86, along County Route 415, more large trees were either uprooted or snapped. One tree temporarily blocked Route 415, and another nearly hit several trailer homes in the Seager Court Trailer Park, and blocked entry to the complex.
The storm then continued northeastward and up a large ridge. Near the ridge top, at the corner of Rumsey Road and Dug Road, a large section of trees were heavily damaged (snapped or uprooted). The center line of the damage appeared to be along Dug Road, with the trees pointed mainly in a westerly direction along the north side of Dug Road, and in an easterly direction along the south side. This damage pattern implied convergent rotation, with an EF1 rating again given at this location.
Little or no damage was found farther to the northeast.

Flash Flood in ONEIDA, NEW YORK
From 28-APR-11 05:00:00 to 28-APR-11 12:00:00 (EST-5)
Location: SAUQUOIT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Roads were flooded, with streams overflowing their bands in Utica and Sauquoit.  Basements were also flooded. In New Hartford and Washington Mills, many roads were impassable with three feet of water on roads.

Thunderstorm Wind in TOMPKINS, NEW YORK
From 28-APR-11 01:45:00 to 28-APR-11 01:45:00 (EST-5)
Location: GROTON
Magnitude: 60.00 EG
Property damage: 12.00K
Crop damage: 0.00K
Reported by: Newspaper

Thunderstorm winds blew down trees, poles and wires in the Groton area.  A roof was blown off a home.

Thunderstorm Wind in CHENANGO, NEW YORK
From 28-APR-11 04:20:00 to 28-APR-11 04:20:00 (EST-5)
Location: BAINBRIDGE
Magnitude: 60.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Trees were damaged, and there was structural damage between County Route 17 and Rounds Road.

Tornado in CHENANGO, NEW YORK
From 28-APR-11 02:58:00 to 28-APR-11 03:03:00 (EST-5)
Location: SMITHVILLE CENTER
Tornado F-scale: EF1
Property damage: 75.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

A tornado touched down in the early morning hours of April 28 about 4.5 miles south-southeast of McDonough and moved northeast cutting a path through heavy woods. The tornado passed just south of Lake Ludlow where a couple homes where damaged by the storm. The tornado path appeared to be its strongest and widest just south of the lake through the wooded area. It continued to the northeast where the path narrowed again and weakened. The tornado lifted a little less than 2 miles south of east McDonough.
A significant swath of trees were also blown down southwest of the tornado track on Waldron Road. These trees were all pointing to the southeast in a slightly divergent pattern and were associated with a significant downburst of wind.

Tornado in CHENANGO, NEW YORK
From 28-APR-11 02:20:00 to 28-APR-11 02:30:00 (EST-5)
Location: PHARSALIA
Tornado F-scale: EF2
Property damage: 625.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

The tornado touched down on county Route 7 in Pharsalia and produced EF1 damage to a few barns and some trees. The tornado traveled northeast approximately 8 miles before dissipating on Pigeon Hill Road in Pharsalia. Intensity for most of the path was estimated at EF1, however EF2 intensity was estimated along North Road and Center Road in Pharsalia. In those areas hundreds of large trees were snapped and uprooted leveling a dense forest. Over the hill a house trailer was lifted and demolished, a two story barn was demolished, a small pond had its water sucked out, and a jeep was moved several feet and hit with debris. Outbuildings were also destroyed.

Hail in ONONDAGA, NEW YORK
From 26-APR-11 16:05:00 to 26-APR-11 16:05:00 (EST-5)
Location: CICERO
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm Wind in ONEIDA, NEW YORK
From 28-APR-11 03:25:00 to 28-APR-11 03:25:00 (EST-5)
Location: UTICA
Magnitude: 60.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: County Official

Trees were blown down. Structural damage was also reported.

Thunderstorm Wind in DELAWARE, NEW YORK
From 28-APR-11 08:53:00 to 28-APR-11 08:53:00 (EST-5)
Location: COLCHESTER
Magnitude: 50.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Numerous trees were blown down throughout the county.