Alert archive / New York / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 795
The Storm Prediction Center issued this severe thunderstorm watch at Aug 21, 2011, 1:20 PM EDT for 6 states. It took effect at Aug 21, 2011, 1:25 PM EDT. It was in force for 8 hr.
The area
The outline as issued.
The facts
- Issued
- Aug 21, 2011, 1:20 PM EDT (17:20 UTC)
- In effect from
- Aug 21, 2011, 1:25 PM EDT
- Expired
- Aug 21, 2011, 9:00 PM EDT
- In force
- 8 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1.5 in
- Strongest gust expected
- 60 kt
All 62 counties
Capitol Planning Region, CT, Northeastern Connecticut Planning Region, CT, Northwest Hills Planning Region, CT, Berkshire County, MA, Essex County, MA, Franklin County, MA, Hampden County, MA, Hampshire County, MA, Middlesex County, MA, Worcester County, MA, Belknap County, NH, Carroll County, NH, Cheshire County, NH, Coos County, NH, Grafton County, NH, Hillsborough County, NH, Merrimack County, NH, Sullivan County, NH, Albany County, NY, Broome County, NY, Chenango County, NY, Columbia County, NY, Cortland County, NY, Delaware County, NY, Dutchess County, NY, Essex County, NY, Fulton County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Madison County, NY, Montgomery County, NY, Oneida County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Tioga County, NY, Ulster County, NY, Warren County, NY, Washington County, NY, Bradford County, PA, Lackawanna County, PA, Luzerne County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA, Addison County, VT, Bennington County, VT, Caledonia County, VT, Chittenden County, VT, Essex County, VT, Lamoille County, VT, Orange County, VT, Orleans County, VT, Rutland County, VT, Washington County, VT, Windham County, VT, Windsor County, VT
The radar
The Albany radar (KENX), 68 km from the middle of the area, began a volume at 17:22 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
- 60%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 30%
- One or more hailstones of 2 inches or more
- 10%
- Six or more combined severe hail and wind reports
- 95%
Warnings issued inside it
33 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 1:21 PM EDT | Tornado Warning | ALY | Dutchess | 39 min |
| Aug 21, 1:23 PM EDT | Severe Thunderstorm Warning | BTV | Caledonia, Essex, Franklin, Lamoille, Orleans, Washington | 82 min |
| Aug 21, 1:30 PM EDT | Severe Thunderstorm Warning | ALY | Northwest Hills Planning Region | 60 min |
| Aug 21, 1:34 PM EDT | Severe Thunderstorm Warning | BTV | Addison, Caledonia, Orange, Rutland, Washington, Windsor | 71 min |
| Aug 21, 1:39 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 66 min |
| Aug 21, 1:51 PM EDT | Severe Thunderstorm Warning | ALY | Berkshire | 54 min |
| Aug 21, 1:59 PM EDT | Severe Thunderstorm Warning | ALY | Northwest Hills Planning Region | 61 min |
| Aug 21, 2:11 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire | 49 min |
| Aug 21, 2:15 PM EDT | Severe Thunderstorm Warning | GYX | Merrimack, Sullivan | 45 min |
| Aug 21, 2:28 PM EDT | Severe Thunderstorm Warning | BOX | Cheshire, Hillsborough | 47 min |
| Aug 21, 2:56 PM EDT | Severe Thunderstorm Warning | GYX | Grafton, Merrimack, Sullivan | 49 min |
| Aug 21, 3:20 PM EDT | Severe Thunderstorm Warning | GYX | Coos, Grafton | 55 min |
| Aug 21, 3:30 PM EDT | Severe Thunderstorm Warning | GYX | Belknap, Carroll, Grafton, Merrimack, Rockingham, Strafford | 45 min |
| Aug 21, 3:40 PM EDT | Severe Thunderstorm Warning | BOX | Capitol Planning Region | 35 min |
| Aug 21, 4:00 PM EDT | Severe Thunderstorm Warning | GYX | Belknap, Carroll, Coos, Grafton, Merrimack, Strafford | 45 min |
| Aug 21, 4:26 PM EDT | Severe Thunderstorm Warning | BTV | Essex | 64 min |
| Aug 21, 4:36 PM EDT | Severe Thunderstorm Warning | GYX | Carroll, Coos, Strafford | 39 min |
| Aug 21, 4:50 PM EDT | Flash Flood Warning | ALY | Warren | 3 hr |
| Aug 21, 5:04 PM EDT | Flash Flood Warning | BTV | Essex | 4 hr |
| Aug 21, 5:48 PM EDT | Severe Thunderstorm Warning | ALY | Warren, Washington | 22 min |
| Aug 21, 5:58 PM EDT | Severe Thunderstorm Warning | BTV | Addison, Orange, Rutland, Washington, Windsor | 62 min |
| Aug 21, 5:59 PM EDT | Severe Thunderstorm Warning | BTV | Rutland, Windsor | 61 min |
| Aug 21, 6:01 PM EDT | Severe Thunderstorm Warning | BTV | Chittenden, Franklin, Lamoille, Orleans | 36 min |
| Aug 21, 6:08 PM EDT | Severe Thunderstorm Warning | ALY | Albany, Columbia, Greene, Rensselaer | 67 min |
| Aug 21, 6:09 PM EDT | Severe Thunderstorm Warning | ALY | Columbia, Greene, Ulster | 39 min |
| Aug 21, 6:25 PM EDT | Severe Thunderstorm Warning | ALY | Berkshire | 65 min |
| Aug 21, 6:43 PM EDT | Severe Thunderstorm Warning | BGM | Delaware, Otsego | 47 min |
| Aug 21, 7:01 PM EDT | Severe Thunderstorm Warning | BTV | Rutland, Windsor | 29 min |
| Aug 21, 7:06 PM EDT | Tornado Warning | ALY | Berkshire | 39 min |
| Aug 21, 7:19 PM EDT | Severe Thunderstorm Warning | GYX | Grafton, Sullivan | 41 min |
| Aug 21, 7:47 PM EDT | Flash Flood Warning | ALY | Berkshire | 3 hr |
| Aug 21, 7:53 PM EDT | Severe Thunderstorm Warning | BOX | Franklin | 23 min |
| Aug 21, 7:58 PM EDT | Severe Thunderstorm Warning | GYX | Belknap, Grafton, Merrimack, Sullivan | 47 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, 5.3 hours before the alert went out and 56 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
- 453 J/kg
- Mixed-layer CIN
- -97 J/kg
- Mixed-layer LCL
- 1024 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 114 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.6
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 21, 11:54 AM EDT | Mesoscale Discussion | SPC | 2 hr | |
| Aug 21, 12:52 PM EDT | Severe Thunderstorm Watch | SPC | Greater Bridgeport Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region | 8 hr |
| Aug 21, 3:05 PM EDT | Mesoscale Discussion | SPC | 55 min | |
| Aug 21, 7:12 PM EDT | Mesoscale Discussion | SPC | 63 min | |
| Aug 21, 4:34 PM EDT | Mesoscale Discussion | SPC | Berkshire | 116 min |
| Aug 21, 3:24 PM EDT | Severe Thunderstorm Watch | SPC | Belknap, Carroll, Coos, Grafton, Merrimack, Rockingham and 2 more | 6 hr |
Nearby
Severe Thunderstorm Watches in New York, 2011Severe Thunderstorm Watches in Vermont, 2011Severe Thunderstorm Watches in New Hampshire, 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.