Alert archive / New York / Severe Thunderstorm Watches in 2021

Severe Thunderstorm Watch 432

August 12, 202123 counties in New York; 7 counties in Pennsylvania

The Storm Prediction Center issued this severe thunderstorm watch at Aug 12, 2021, 1:42 PM EDT for 23 counties in New York; 7 counties in Pennsylvania. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Aug 12, 2021, 1:42 PM EDT (17:42 UTC)
Expired
Aug 12, 2021, 8:00 PM EDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
1 in
Strongest gust expected
60 kt
All 30 counties

Albany County, NY, Broome County, NY, Chenango County, NY, Columbia County, NY, Cortland County, NY, Delaware 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

The radar

The Binghamton radar (KBGM), 67 km from the middle of the area, began a volume at 17:46 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
5%
One or more EF2 to EF5 tornadoes
2%
Ten or more severe wind reports
70%
One or more gusts of 65 knots or more
20%
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
90%

Warnings issued inside it

9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Aug 12, 1:51 PM EDTSevere Thunderstorm WarningALYAlbany, Montgomery, Saratoga, Schenectady, Schoharie54 min
Aug 12, 2:14 PM EDTSevere Thunderstorm Warning Considerable damage threatBGMLackawanna, Luzerne, Wyoming46 min
Aug 12, 2:42 PM EDTSevere Thunderstorm WarningALYAlbany, Rensselaer, Saratoga, Schenectady48 min
Aug 12, 2:59 PM EDTSevere Thunderstorm WarningBGMLackawanna, Luzerne, Pike, Wayne, Wyoming31 min
Aug 12, 3:12 PM EDTSevere Thunderstorm WarningALYAlbany, Columbia, Rensselaer18 min
Aug 12, 3:28 PM EDTSevere Thunderstorm WarningBGMLackawanna, Pike, Wayne47 min
Aug 12, 3:29 PM EDTSevere Thunderstorm WarningALYColumbia, Rensselaer61 min
Aug 12, 3:44 PM EDTSevere Thunderstorm WarningALYAlbany, Columbia, Greene46 min
Aug 12, 4:29 PM EDTSevere Thunderstorm WarningALYColumbia61 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, 5.7 hours before the alert went out and 119 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.

Skew-T log-pSkew-T log-p diagram, Albany, NY at 12:00Z on 2021-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 58 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Albany, NY at 12:00Z on 2021-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 62 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
58 J/kg
Mixed-layer CIN
-212 J/kg
Mixed-layer LCL
1178 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
62 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 12, 11:03 AM EDTMesoscale DiscussionSPCAlbany, Broome, Chenango, Clinton, Cortland, Delaware and 19 more2 hr
Aug 12, 12:19 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Blair, Butler, Cambria, Cameron and 20 more116 min
Aug 12, 1:11 PM EDTSevere Thunderstorm WatchSPCArmstrong, Bedford, Blair, Cambria, Cameron, Centre and 27 more9 hr
Aug 12, 3:17 PM EDTMesoscale DiscussionSPCAllegheny, Beaver, Butler, Crawford, Lawrence, Mercer and 1 more58 min
Aug 12, 3:48 PM EDTSevere Thunderstorm WatchSPCAllegheny, Armstrong, Beaver, Butler, Clarion, Crawford and 11 more6 hr
Aug 12, 6:22 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Blair, Butler, Cambria and 21 more83 min

Nearby

Severe Thunderstorm Watches in New York, 2021Severe Thunderstorm Watches in Pennsylvania, 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.