Alert archive / New York / Severe Thunderstorm Watches in 2011
Severe Thunderstorm Watch 831
The Storm Prediction Center issued this severe thunderstorm watch at Sep 4, 2011, 3:26 AM EDT for 22 counties in New York. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Sep 4, 2011, 3:26 AM EDT (07:26 UTC)
- Expired
- Sep 4, 2011, 7:05 AM EDT
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 1 in
- Strongest gust expected
- 60 kt
All 22 counties
Allegany County, NY, Cattaraugus County, NY, Cayuga County, NY, Chautauqua County, NY, Erie County, NY, Genesee County, NY, Jefferson County, NY, Lewis County, NY, Livingston County, NY, Madison County, NY, Monroe County, NY, Niagara County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Orleans County, NY, Oswego County, NY, Seneca County, NY, Steuben County, NY, Wayne County, NY, Wyoming County, NY, Yates County, NY
The radar
The Buffalo radar (KBUF), 66 km from the middle of the area, began a volume at 07:27 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
- 2%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 5%
- Ten or more severe hail reports
- 20%
- One or more hailstones of 2 inches or more
- 5%
- Six or more combined severe hail and wind reports
- 70%
Warnings issued inside it
2 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 4:09 AM EDT | Severe Thunderstorm Warning | BUF | Erie, Niagara | 57 min |
| Sep 4, 4:41 AM EDT | Severe Thunderstorm Warning | BUF | Erie, Genesee, Monroe, Niagara, Orleans | 45 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
Buffalo Intl Airport, NY (KBUF), launched 00:00Z, 7.4 hours before the alert went out and 64 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
- 889 J/kg
- Mixed-layer CIN
- -92 J/kg
- Mixed-layer LCL
- 1459 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 86 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 3:07 AM EDT | Mesoscale Discussion | SPC | Allegany, Cattaraugus, Cayuga, Erie, Genesee, Livingston and 8 more | 83 min |
| Sep 4, 6:22 AM EDT | Mesoscale Discussion | SPC | Cayuga, Jefferson, Lewis, Oneida, Onondaga, Ontario and 4 more | 83 min |
| Sep 4, 1:33 PM EDT | Mesoscale Discussion | SPC | Broome, Chemung, Chenango, Cortland, Delaware, Fulton and 13 more | 87 min |
| Sep 4, 2:43 PM EDT | Severe Thunderstorm Watch | SPC | Albany, Broome, Cayuga, Chemung, Chenango, Clinton and 30 more | 8 hr |
| Sep 4, 6:06 PM EDT | Mesoscale Discussion | SPC | Albany, Broome, Cayuga, Chemung, Chenango, Clinton and 30 more | 54 min |
Nearby
Severe Thunderstorm Watches in New York, 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.