Alert archive / New York / Severe Thunderstorm Watches in 2009
Severe Thunderstorm Watch 280
The Storm Prediction Center issued this severe thunderstorm watch at May 9, 2009, 12:43 PM EDT for 48 counties in New York; 6 counties in Vermont. It was in force for 6 hr.
The area
The outline as issued.
The facts
- Issued
- May 9, 2009, 12:43 PM EDT (16:43 UTC)
- Expired
- May 9, 2009, 7:00 PM EDT
- In force
- 6 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
All 54 counties
Albany County, NY, Allegany County, NY, Broome County, NY, Cattaraugus County, NY, Cayuga County, NY, Chautauqua County, NY, Chemung County, NY, Chenango County, NY, Clinton County, NY, Columbia County, NY, Cortland County, NY, Delaware County, NY, Erie County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Genesee County, NY, Greene County, NY, Hamilton County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Livingston County, NY, Madison County, NY, Monroe County, NY, Montgomery County, NY, Niagara County, NY, Oneida County, NY, Onondaga County, NY, Ontario County, NY, Orleans County, NY, Oswego County, NY, Otsego County, NY, Rensselaer County, NY, Saratoga County, NY, Schenectady County, NY, Schoharie County, NY, Schuyler County, NY, Seneca County, NY, St. Lawrence County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Warren County, NY, Washington County, NY, Wayne County, NY, Wyoming County, NY, Yates County, NY, Addison County, VT, Bennington County, VT, Chittenden County, VT, Grand Isle County, VT, Rutland County, VT, Windham County, VT
The radar
The Ft Drum radar (KTYX), 90 km from the middle of the area, began a volume at 16:45 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
- 60%
- 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
- 80%
Warnings issued inside it
16 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 1:28 PM EDT | Severe Thunderstorm Warning | BUF | Jefferson | 46 min |
| May 9, 1:48 PM EDT | Severe Thunderstorm Warning | BUF | Jefferson, Lewis | 57 min |
| May 9, 1:55 PM EDT | Severe Thunderstorm Warning | BTV | St. Lawrence | 65 min |
| May 9, 2:12 PM EDT | Severe Thunderstorm Warning | BUF | Wayne | 40 min |
| May 9, 2:19 PM EDT | Severe Thunderstorm Warning | ALY | Hamilton, Herkimer | 56 min |
| May 9, 3:13 PM EDT | Severe Thunderstorm Warning | BGM | Chenango, Otsego | 47 min |
| May 9, 3:37 PM EDT | Severe Thunderstorm Warning | BTV | Essex, Franklin | 53 min |
| May 9, 3:52 PM EDT | Severe Thunderstorm Warning | ALY | Fulton, Hamilton, Herkimer | 53 min |
| May 9, 4:04 PM EDT | Severe Thunderstorm Warning | BGM | Oneida | 29 min |
| May 9, 4:29 PM EDT | Severe Thunderstorm Warning | ALY | Fulton, Hamilton, Saratoga, Warren | 61 min |
| May 9, 4:59 PM EDT | Severe Thunderstorm Warning | BTV | Addison, Orange, Rutland, Washington, Windsor | 50 min |
| May 9, 5:14 PM EDT | Severe Thunderstorm Warning | BGM | Broome, Delaware | 46 min |
| May 9, 5:43 PM EDT | Severe Thunderstorm Warning | ALY | Albany, Columbia, Rensselaer | 47 min |
| May 9, 5:54 PM EDT | Severe Thunderstorm Warning | ALY | Washington | 66 min |
| May 9, 6:22 PM EDT | Severe Thunderstorm Warning | ALY | Columbia, Rensselaer | 38 min |
| May 9, 6:57 PM EDT | Severe Thunderstorm Warning | ALY | Columbia | 63 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 12:00Z, 4.7 hours before the alert went out and 171 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
- 201 J/kg
- Mixed-layer CIN
- -22 J/kg
- Mixed-layer LCL
- 697 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 79 m²/s²
- 0-3 km storm-relative helicity
- 175 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 9, 11:52 AM EDT | Mesoscale Discussion | SPC | Albany, Allegany, Cayuga, Chenango, Cortland, Essex and 24 more | 83 min |
| May 9, 2:56 PM EDT | Mesoscale Discussion | SPC | Albany, Chenango, Delaware, Essex, Fulton, Greene and 9 more | 94 min |
| May 9, 6:47 PM EDT | Mesoscale Discussion | SPC | Columbia, Dutchess, Orange, Putnam, Rockland, Ulster and 1 more | 88 min |
| May 9, 3:40 PM EDT | Severe Thunderstorm Watch | SPC | Caledonia, Essex, Franklin, Lamoille, Orange, Orleans and 2 more | 6 hr |
Nearby
Severe Thunderstorm Watches in New York, 2009Severe Thunderstorm Watches in Vermont, 2009Every severe thunderstorm watch in 2009
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.