Alert archive / New York / Severe Thunderstorm Watches in 2021
Severe Thunderstorm Watch 303
The Storm Prediction Center issued this severe thunderstorm watch at Jun 21, 2021, 3:45 PM EDT for 4 states. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 21, 2021, 3:45 PM EDT (19:45 UTC)
- Expired
- Jun 21, 2021, 10:45 PM EDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 2 in
- Strongest gust expected
- 60 kt
Counties Northwest Hills Planning Region, CT, Berkshire County, MA, Albany County, NY, Columbia County, NY, Delaware County, NY, Dutchess County, NY, Greene County, NY, Otsego County, NY, Rensselaer County, NY, Schenectady County, NY, Schoharie County, NY, Sullivan County, NY, Ulster County, NY, Bradford County, PA, Lackawanna County, PA, Luzerne County, PA, Pike County, PA, Susquehanna County, PA, Wayne County, PA, Wyoming County, PA
The radar
The Binghamton radar (KBGM), 66 km from the middle of the area, began a volume at 19:46 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
- 20%
- Ten or more severe hail reports
- 40%
- One or more hailstones of 2 inches or more
- 30%
- Six or more combined severe hail and wind reports
- 90%
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 |
|---|---|---|---|---|
| Jun 21, 4:42 PM EDT | Severe Thunderstorm Warning | BGM | Bradford | 48 min |
| Jun 21, 5:18 PM EDT | Severe Thunderstorm Warning | BGM | Bradford | 42 min |
| Jun 21, 6:27 PM EDT | Severe Thunderstorm Warning | BGM | Bradford, Lackawanna, Luzerne, Susquehanna, Wyoming | 48 min |
| Jun 21, 6:56 PM EDT | Severe Thunderstorm Warning | BGM | Chenango, Otsego | 64 min |
| Jun 21, 7:09 PM EDT | Severe Thunderstorm Warning | BGM | Lackawanna, Luzerne, Susquehanna, Wayne, Wyoming | 66 min |
| Jun 21, 7:35 PM EDT | Severe Thunderstorm Warning | BGM | Delaware | 40 min |
| Jun 21, 7:47 PM EDT | Severe Thunderstorm Warning | BGM | Chenango, Delaware, Otsego | 39 min |
| Jun 21, 7:56 PM EDT | Severe Thunderstorm Warning | BGM | Sullivan | 64 min |
| Jun 21, 8:12 PM EDT | Severe Thunderstorm Warning | ALY | Greene, Schoharie | 51 min |
| Jun 21, 8:22 PM EDT | Severe Thunderstorm Warning | BGM | Delaware, Sullivan | 38 min |
| Jun 21, 8:37 PM EDT | Severe Thunderstorm Warning | ALY | Greene, Ulster | 53 min |
| Jun 21, 8:43 PM EDT | Severe Thunderstorm Warning | ALY | Montgomery, Saratoga, Schenectady | 62 min |
| Jun 21, 8:49 PM EDT | Severe Thunderstorm Warning | ALY | Albany, Schenectady, Schoharie | 30 min |
| Jun 21, 9:11 PM EDT | Severe Thunderstorm Warning | BGM | Sullivan | 19 min |
| Jun 21, 9:44 PM EDT | Severe Thunderstorm Warning | ALY | Albany, Rensselaer, Saratoga | 61 min |
| Jun 21, 9:49 PM EDT | Severe Thunderstorm Warning | ALY | Columbia, Dutchess, Greene, Ulster | 56 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
- Mesoscale Discussion 1046 Severe potential...watch likely
- Mesoscale Discussion 1048 Severe potential...severe thunderstorm watch likely
- Mesoscale Discussion 1049 Severe thunderstorm watch 300
- Mesoscale Discussion 1056 Severe thunderstorm watch 300...303
- Mesoscale Discussion 1059 Severe thunderstorm watch 300...303...304
The nearest sounding before it
Albany, NY (KALY), launched 12:00Z, 7.8 hours before the alert went out and 130 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
- 524 J/kg
- Mixed-layer CIN
- -118 J/kg
- Mixed-layer LCL
- 990 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 162 m²/s²
- 0-3 km storm-relative helicity
- 192 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.4
The text
As transmitted.
095
WWUS20 KWNS 211943
SEL3
SPC WW 211943
CTZ000-MAZ000-NYZ000-PAZ000-220300-
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 303
NWS Storm Prediction Center Norman OK
345 PM EDT Mon Jun 21 2021
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Western Connecticut
Western Massachusetts
Eastern New York
Northeast Pennsylvania
* Effective this Monday afternoon and evening from 345 PM until
1100 PM EDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
A tornado or two possible
SUMMARY...Thunderstorms over central PA/NY will spread eastward
across the watch area through early evening, posing a risk of
locally damaging wind gusts and large hail.
The severe thunderstorm watch area is approximately along and 50
statute miles north and south of a line from 55 miles southwest of
Binghamton NY to 20 miles east of Pittsfield MA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU3).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 299...WW 300...WW
301...WW 302...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 60 knots. A
few cumulonimbi with maximum tops to 500. Mean storm motion vector
26035.
...HartSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 21, 11:59 AM EDT | Mesoscale Discussion | SPC | Cattaraugus, Chautauqua | 91 min |
| Jun 21, 12:31 PM EDT | Mesoscale Discussion | SPC | Clinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 12 more | 89 min |
| Jun 21, 12:31 PM EDT | Severe Thunderstorm Watch | SPC | Allegany, Cattaraugus, Cayuga, Chautauqua, Erie, Genesee and 14 more | 7 hr |
| Jun 21, 1:11 PM EDT | Severe Thunderstorm Watch | SPC | Broome, Chemung, Chenango, Clinton, Cortland, Essex and 14 more | 10 hr |
| Jun 21, 3:35 PM EDT | Mesoscale Discussion | SPC | Clinton, Essex, Franklin, Fulton, Hamilton, Herkimer and 7 more | 85 min |
| Jun 21, 3:47 PM EDT | Mesoscale Discussion | SPC | Allegany, Livingston, Ontario, Steuben, Wayne, Yates | 58 min |
| Jun 21, 4:33 PM EDT | Severe Thunderstorm Watch | SPC | Orange | 6 hr |
| Jun 21, 6:50 PM EDT | Mesoscale Discussion | SPC | Albany, Broome, Chenango, Columbia, Cortland, Delaware and 23 more | 55 min |
| Jun 21, 1:51 PM EDT | Mesoscale Discussion | SPC | Adams, Bedford, Berks, Blair, Bradford, Bucks and 37 more | 114 min |
| Jun 21, 2:20 PM EDT | Severe Thunderstorm Watch | SPC | Adams, Bedford, Blair, Centre, Clinton, Columbia and 19 more | 6 hr |
| Jun 21, 6:15 PM EDT | Mesoscale Discussion | SPC | Bucks, Chester, Delaware, Lancaster, Montgomery, Philadelphia | 60 min |
Nearby
Severe Thunderstorm Watches in New York, 2021Severe Thunderstorm Watches in Pennsylvania, 2021Severe Thunderstorm Watches in Connecticut, 2021Every severe thunderstorm watch in 2021
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.