Alert archive / New York / Severe Thunderstorm Watches in 2011

Severe Thunderstorm Watch 244

April 27, 20115 states

The Storm Prediction Center issued this severe thunderstorm watch at Apr 27, 2011, 8:15 PM EDT for 5 states. It was in force for 8 hr.

The area

The outline as issued.

The facts

Issued: Apr 27, 2011, 8:15 PM EDT (00:15 UTC)
Expired: Apr 28, 2011, 4:00 AM EDT
In force: 8 hr
Issued by: the Storm Prediction Center
Largest hail expected: 1.5 in
Strongest gust expected: 60 kt

All 57 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Hunterdon County, NJ, Mercer County, NJ, Morris County, NJ, Passaic County, NJ, Somerset County, NJ, Sussex County, NJ, Warren County, NJ, Albany County, NY, Broome County, NY, Chenango County, NY, Clinton County, NY, Cortland County, NY, Delaware County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Onondaga County, NY, Orange County, NY, Otsego County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, St. Lawrence County, NY, Sullivan County, NY, Ulster County, NY, Warren County, NY, Berks County, PA, Bradford County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lackawanna County, PA, Lehigh County, PA, Luzerne County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA

The radar

The Binghamton radar (KBGM), 72 km from the middle of the area, began a volume at 00:15 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes: 20%
One or more EF2 to EF5 tornadoes: 5%
Ten or more severe wind reports: 30%
One or more gusts of 65 knots or more: 30%
Ten or more severe hail reports: 30%
One or more hailstones of 2 inches or more: 20%
Six or more combined severe hail and wind reports: 70%

Warnings issued inside it

31 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Apr 27, 8:22 PM EDT	Severe Thunderstorm Warning	BGM	Bradford	53 min
Apr 27, 8:33 PM EDT	Flash Flood Warning	BGM	Bradford	2 hr
Apr 27, 8:44 PM EDT	Severe Thunderstorm Warning	BGM	Cayuga, Chemung, Chenango, Cortland, Madison, Onondaga and 4 more	61 min
Apr 27, 9:02 PM EDT	Severe Thunderstorm Warning	BGM	Bradford, Susquehanna, Wyoming	43 min
Apr 27, 9:09 PM EDT	Severe Thunderstorm Warning	BGM	Luzerne, Susquehanna, Wyoming	51 min
Apr 27, 9:40 PM EDT	Severe Thunderstorm Warning	BGM	Broome, Chenango, Cortland, Tioga	41 min
Apr 27, 10:18 PM EDT	Severe Thunderstorm Warning	BGM	Chenango, Delaware, Madison, Oneida, Otsego	57 min
Apr 27, 10:26 PM EDT	Flash Flood Warning	BGM	Madison, Oneida	2 hr
Apr 27, 10:35 PM EDT	Severe Thunderstorm Warning	BGM	Delaware, Otsego	55 min
Apr 27, 10:36 PM EDT	Severe Thunderstorm Warning	BGM	Delaware	54 min
Apr 27, 11:09 PM EDT	Severe Thunderstorm Warning	ALY	Albany, Fulton, Montgomery, Saratoga, Schenectady, Schoharie	66 min
Apr 27, 11:29 PM EDT	Severe Thunderstorm Warning	ALY	Fulton, Hamilton, Herkimer, Saratoga, Warren	35 min
Apr 27, 11:37 PM EDT	Severe Thunderstorm Warning	BTV	Clinton, Franklin	38 min
Apr 28, 1:22 AM EDT	Severe Thunderstorm Warning	BGM	Cayuga, Chemung, Cortland, Tioga, Tompkins	53 min
Apr 28, 1:53 AM EDT	Tornado Warning	BGM	Cayuga, Cortland, Tompkins	52 min
Apr 28, 2:13 AM EDT	Severe Thunderstorm Warning	BGM	Bradford	47 min
Apr 28, 2:27 AM EDT	Tornado Warning	BGM	Cortland, Madison, Onondaga	33 min
Apr 28, 2:34 AM EDT	Severe Thunderstorm Warning	BGM	Chenango, Cortland, Madison	41 min
Apr 28, 2:43 AM EDT	Tornado Warning	BGM	Chenango, Cortland, Madison	47 min
Apr 28, 2:48 AM EDT	Severe Thunderstorm Warning	BGM	Broome, Chenango, Cortland, Tioga	27 min
Apr 28, 3:00 AM EDT	Flash Flood Warning	BGM	Bradford	10 hr
Apr 28, 3:08 AM EDT	Tornado Warning	BGM	Chenango, Madison, Oneida	37 min
Apr 28, 3:12 AM EDT	Tornado Warning	BGM	Chenango, Cortland	63 min
Apr 28, 3:29 AM EDT	Flash Flood Warning	BGM	Cortland, Tioga, Tompkins	10 hr
Apr 28, 3:40 AM EDT	Flash Flood Warning	BGM	Broome, Chenango, Madison, Oneida	10 hr
Apr 28, 3:41 AM EDT	Severe Thunderstorm Warning	BGM	Oneida	34 min
Apr 28, 3:45 AM EDT	Severe Thunderstorm Warning	BGM	Broome, Chenango, Cortland	45 min
Apr 28, 3:47 AM EDT	Tornado Warning	BGM	Madison, Oneida	28 min
Apr 28, 3:49 AM EDT	Tornado Warning	BGM	Chenango, Madison, Oneida	26 min
Apr 28, 3:51 AM EDT	Severe Thunderstorm Warning	BGM	Broome, Chenango, Tioga	54 min
Apr 28, 3:55 AM EDT	Tornado Warning	ALY	Hamilton, Herkimer	50 min

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Albany, NY (KALY), launched 00:00Z, 0.3 hours before the alert went out and 113 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 108 J/kg
Mixed-layer CIN: -95 J/kg
Mixed-layer LCL: 777 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 307 m²/s²
0-3 km storm-relative helicity: 401 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.8

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 28, 4:05 AM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	6 hr
Apr 28, 6:21 AM EDT	Mesoscale Discussion	SPC	Kent, New Castle	54 min
Apr 28, 9:45 AM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	6 hr
Apr 28, 10:44 AM EDT	Mesoscale Discussion	SPC	Kent, New Castle	61 min
Apr 28, 11:49 AM EDT	Mesoscale Discussion	SPC	Kent, New Castle	56 min
Apr 28, 2:00 PM EDT	Mesoscale Discussion	SPC	Kent, Sussex	60 min
Apr 28, 12:27 AM EDT	Mesoscale Discussion	SPC	Allegany, Frederick, Howard, Montgomery, Washington	63 min
Apr 28, 12:41 AM EDT	Tornado Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more	7 hr
Apr 28, 7:38 AM EDT	Tornado Watch	SPC	Anne Arundel, Baltimore, Calvert, Carroll, Charles, Dorchester and 10 more	7 hr
Apr 28, 2:41 PM EDT	Tornado Watch	SPC	Dorchester, Somerset, Wicomico, Worcester	6 hr
Apr 28, 6:33 PM EDT	Mesoscale Discussion	SPC	Dorchester, Saint Mary's, Somerset, Wicomico, Worcester	57 min
Apr 28, 3:32 AM EDT	Mesoscale Discussion	SPC	Hunterdon, Sussex, Warren	28 min
Apr 27, 9:03 PM EDT	Mesoscale Discussion	SPC	Cayuga, Chemung, Tioga, Tompkins	57 min
Apr 27, 10:45 PM EDT	Mesoscale Discussion	SPC	Albany, Broome, Chenango, Delaware, Essex, Franklin and 15 more	60 min
Apr 28, 2:20 AM EDT	Mesoscale Discussion	SPC	Broome, Chemung, Chenango, Cortland, Delaware, Fulton and 13 more	55 min
Apr 27, 11:50 PM EDT	Severe Thunderstorm Watch	SPC	Adams, Bedford, Blair, Cambria, Cameron, Centre and 26 more	7 hr

Nearby

Severe Thunderstorm Watches in New York, 2011 Severe Thunderstorm Watches in Pennsylvania, 2011 Severe Thunderstorm Watches in New Jersey, 2011 Every severe thunderstorm watch in 2011

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.