Alert archive / New York / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 253
The Storm Prediction Center issued this severe thunderstorm watch at Apr 28, 2011, 9:45 AM EDT for 8 states. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- Apr 28, 2011, 9:45 AM EDT (13:45 UTC)
- Expired
- Apr 28, 2011, 3:39 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 66 counties
Greater Bridgeport Planning Region, CT, Northwest Hills Planning Region, CT, Kent County, DE, New Castle County, DE, Sussex County, DE, Berkshire County, MA, Caroline County, MD, Cecil County, MD, Kent County, MD, Queen Anne's County, MD, Talbot County, MD, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Morris County, NJ, Ocean County, NJ, Passaic County, NJ, Salem County, NJ, Somerset County, NJ, Sussex County, NJ, Union County, NJ, Warren County, NJ, Albany County, NY, Bronx County, NY, Columbia County, NY, Dutchess County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Kings County, NY, Montgomery County, NY, Nassau County, NY, New York County, NY, Orange County, NY, Putnam County, NY, Queens County, NY, Rensselaer County, NY, Richmond County, NY, Rockland County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Westchester County, NY, Bucks County, PA, Chester County, PA, Delaware County, PA, Monroe County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, Bennington County, VT, Windham County, VT
The radar
The Albany radar (KENX), 77 km from the middle of the area, began a volume at 13:45 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
- 10%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
18 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 10:00 AM EDT | Severe Thunderstorm Warning | PHI | Berks, Bucks, Chester, Lehigh, Montgomery | 60 min |
| Apr 28, 10:13 AM EDT | Severe Thunderstorm Warning | ALY | Albany, Fulton, Greene, Montgomery, Schenectady, Schoharie and 1 more | 32 min |
| Apr 28, 10:25 AM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Morris, Sussex, Warren | 50 min |
| Apr 28, 10:41 AM EDT | Severe Thunderstorm Warning | ALY | Greene, Ulster | 34 min |
| Apr 28, 10:57 AM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Mercer, Middlesex, Somerset, Warren | 63 min |
| Apr 28, 10:58 AM EDT | Tornado Warning | PHI | Hunterdon, Warren | 32 min |
| Apr 28, 11:11 AM EDT | Severe Thunderstorm Warning | PHI | Hunterdon, Morris, Somerset, Sussex, Warren | 64 min |
| Apr 28, 11:22 AM EDT | Tornado Warning | PHI | Hunterdon, Morris, Sussex, Warren | 23 min |
| Apr 28, 11:37 AM EDT | Severe Thunderstorm Warning | PHI | Kent, New Castle | 53 min |
| Apr 28, 11:42 AM EDT | Flash Flood Warning | OKX | Bergen, Passaic | 2 hr |
| Apr 28, 11:43 AM EDT | Tornado Warning | OKX | Bergen, Essex, Passaic | 32 min |
| Apr 28, 11:45 AM EDT | Tornado Warning | PHI | Morris | 30 min |
| Apr 28, 11:47 AM EDT | Severe Thunderstorm Warning | ALY | Saratoga, Schenectady, Washington | 28 min |
| Apr 28, 12:06 PM EDT | Severe Thunderstorm Warning | OKX | Bergen, Essex, Passaic, Union | 24 min |
| Apr 28, 12:11 PM EDT | Severe Thunderstorm Warning | PHI | Bucks, Chester, Delaware, Montgomery | 31 min |
| Apr 28, 12:16 PM EDT | Severe Thunderstorm Warning | OKX | Bergen, Essex, Passaic | 29 min |
| Apr 28, 2:02 PM EDT | Severe Thunderstorm Warning | PHI | Atlantic, Burlington, Camden, Gloucester | 41 min |
| Apr 28, 2:27 PM EDT | Severe Thunderstorm Warning | PHI | Burlington, Monmouth, Ocean | 41 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 12:00Z, 1.8 hours before the alert went out and 97 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.
- Mixed-layer CAPE
- 354 J/kg
- Mixed-layer CIN
- -37 J/kg
- Mixed-layer LCL
- 613 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 258 m²/s²
- 0-3 km storm-relative helicity
- 254 m²/s²
- Significant tornado parameter
- 0.7
- Supercell composite
- 5.7
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 11:49 AM EDT | Mesoscale Discussion | SPC | 56 min | |
| Apr 27, 8:15 PM EDT | Severe Thunderstorm Watch | SPC | Kent, New Castle, Sussex | 8 hr |
| 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, 10:44 AM EDT | Mesoscale Discussion | SPC | Kent, New Castle | 61 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, 2011Severe Thunderstorm Watches in New Jersey, 2011Severe Thunderstorm Watches in Pennsylvania, 2011Every 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.