Alert archive / Pennsylvania / Severe Thunderstorm Watches in 2012

Severe Thunderstorm Watch 312

May 29, 20124 states

The Storm Prediction Center issued this severe thunderstorm watch at May 29, 2012, 10:27 AM EDT for 4 states. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
May 29, 2012, 10:27 AM EDT (14:27 UTC)
Expired
May 29, 2012, 3:49 PM EDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
2 in
Strongest gust expected
60 kt
All 65 counties

Allegany County, NY, Cattaraugus County, NY, Cayuga County, NY, Chautauqua County, NY, Jefferson County, NY, Lewis County, NY, Livingston County, NY, Monroe County, NY, Onondaga County, NY, Ontario County, NY, Oswego County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Wayne County, NY, Wyoming County, NY, Yates County, NY, Ashtabula County, OH, Belmont County, OH, Carroll County, OH, Columbiana County, OH, Coshocton County, OH, Guernsey County, OH, Harrison County, OH, Jefferson County, OH, Mahoning County, OH, Monroe County, OH, Muskingum County, OH, Noble County, OH, Portage County, OH, Stark County, OH, Trumbull County, OH, Tuscarawas County, OH, Allegheny County, PA, Armstrong County, PA, Beaver County, PA, Butler County, PA, Cambria County, PA, Cameron County, PA, Clarion County, PA, Clearfield County, PA, Crawford County, PA, Elk County, PA, Erie County, PA, Fayette County, PA, Forest County, PA, Greene County, PA, Indiana County, PA, Jefferson County, PA, Lawrence County, PA, McKean County, PA, Mercer County, PA, Potter County, PA, Somerset County, PA, Venango County, PA, Warren County, PA, Washington County, PA, Westmoreland County, PA, Brooke County, WV, Hancock County, WV, Marion County, WV, Marshall County, WV, Monongalia County, WV, Ohio County, WV, Wetzel County, WV

The radar

The Buffalo radar (KBUF), 98 km from the middle of the area, began a volume at 14:29 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
70%
One or more gusts of 65 knots or more
20%
Ten or more severe hail reports
70%
One or more hailstones of 2 inches or more
20%
Six or more combined severe hail and wind reports
90%

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
May 29, 10:32 AM EDTSevere Thunderstorm WarningCLEPortage43 min
May 29, 10:38 AM EDTSevere Thunderstorm WarningPBZMarshall, Wetzel37 min
May 29, 10:41 AM EDTSevere Thunderstorm WarningCLETrumbull49 min
May 29, 10:45 AM EDTSevere Thunderstorm WarningCLECrawford, Erie60 min
May 29, 10:47 AM EDTSevere Thunderstorm WarningCLEAshtabula43 min
May 29, 10:50 AM EDTSevere Thunderstorm WarningCLEMahoning55 min
May 29, 10:55 AM EDTSevere Thunderstorm WarningCLEStark26 min
May 29, 11:14 AM EDTSevere Thunderstorm WarningPBZMercer31 min
May 29, 11:20 AM EDTSevere Thunderstorm WarningPBZButler25 min
May 29, 11:22 AM EDTSevere Thunderstorm WarningCLETrumbull38 min
May 29, 11:24 AM EDTSevere Thunderstorm WarningBUFChautauqua66 min
May 29, 11:27 AM EDTSevere Thunderstorm WarningPBZMercer48 min
May 29, 11:37 AM EDTSevere Thunderstorm WarningCLECrawford, Erie38 min
May 29, 11:39 AM EDTSevere Thunderstorm WarningBUFErie, Wyoming51 min
May 29, 11:40 AM EDTSevere Thunderstorm WarningPBZColumbiana35 min
May 29, 11:47 AM EDTSevere Thunderstorm WarningCTPWarren58 min
May 29, 11:52 AM EDTSevere Thunderstorm WarningPBZMercer, Venango38 min
May 29, 11:54 AM EDTSevere Thunderstorm WarningPBZArmstrong, Butler, Clarion51 min
May 29, 12:11 PM EDTSevere Thunderstorm WarningBUFOswego64 min
May 29, 12:13 PM EDTSevere Thunderstorm WarningBUFLivingston, Ontario62 min
May 29, 12:19 PM EDTSevere Thunderstorm WarningCLECrawford11 min
May 29, 12:20 PM EDTSevere Thunderstorm WarningBUFGenesee, Livingston, Wyoming41 min
May 29, 12:32 PM EDTSevere Thunderstorm WarningPBZClarion, Forest, Venango58 min
May 29, 12:41 PM EDTSevere Thunderstorm WarningBGMSteuben, Yates64 min
May 29, 12:41 PM EDTSevere Thunderstorm WarningBUFCayuga, Oswego, Wayne44 min
May 29, 12:47 PM EDTSevere Thunderstorm WarningBUFOntario58 min
May 29, 12:49 PM EDTSevere Thunderstorm WarningBUFLivingston, Monroe, Ontario41 min
May 29, 1:14 PM EDTSevere Thunderstorm WarningBGMOneida, Onondaga61 min
May 29, 1:14 PM EDTSevere Thunderstorm WarningPBZAllegheny46 min
May 29, 1:17 PM EDTSevere Thunderstorm WarningBUFWayne58 min
May 29, 1:20 PM EDTSevere Thunderstorm WarningBUFLewis, Oswego55 min
May 29, 1:22 PM EDTSevere Thunderstorm WarningCTPCameron, Clearfield, Elk53 min
May 29, 1:23 PM EDTSevere Thunderstorm WarningBGMCayuga, Seneca67 min
May 29, 1:23 PM EDTSevere Thunderstorm WarningBGMChemung, Schuyler, Steuben67 min
May 29, 1:27 PM EDTSevere Thunderstorm WarningBUFAllegany, Cattaraugus, Livingston63 min
May 29, 1:27 PM EDTSevere Thunderstorm WarningPBZAllegheny, Armstrong, Butler, Westmoreland33 min
May 29, 1:36 PM EDTSevere Thunderstorm WarningCTPMcKean, Potter69 min
May 29, 1:39 PM EDTSevere Thunderstorm WarningPBZArmstrong, Indiana36 min
May 29, 1:47 PM EDTSevere Thunderstorm WarningBUFLewis, Oswego38 min
May 29, 1:51 PM EDTSevere Thunderstorm WarningBGMSchuyler, Seneca, Steuben, Yates35 min
May 29, 1:59 PM EDTSevere Thunderstorm WarningPBZArmstrong, Clarion, Indiana, Jefferson46 min
May 29, 2:05 PM EDTSevere Thunderstorm WarningBGMCayuga, Madison, Onondaga55 min
May 29, 2:05 PM EDTSevere Thunderstorm WarningBGMChemung, Cortland, Schuyler, Tioga, Tompkins55 min
May 29, 2:07 PM EDTSevere Thunderstorm WarningCTPCameron, Clinton, Elk, Potter38 min
May 29, 2:09 PM EDTSevere Thunderstorm WarningBGMCayuga, Cortland, Madison, Onondaga66 min
May 29, 2:12 PM EDTSevere Thunderstorm WarningCTPCambria, Clearfield, Elk63 min
May 29, 2:13 PM EDTSevere Thunderstorm WarningBGMCayuga, Cortland, Onondaga, Seneca62 min
May 29, 2:15 PM EDTSevere Thunderstorm WarningPBZIndiana, Jefferson30 min
May 29, 2:18 PM EDTSevere Thunderstorm WarningBUFOswego43 min
May 29, 2:27 PM EDTSevere Thunderstorm WarningBGMBroome, Chemung, Cortland, Schuyler, Tioga, Tompkins63 min
May 29, 2:35 PM EDTSevere Thunderstorm WarningBGMCayuga, Schuyler, Seneca, Steuben, Yates40 min
May 29, 2:43 PM EDTSevere Thunderstorm WarningCTPClinton, Lycoming, Potter62 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, 2.5 hours before the alert went out and 95 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, Buffalo Intl Airport, NY at 12:00Z on 2012-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1783 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, Buffalo Intl Airport, NY at 12:00Z on 2012-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 square meters per square second.19395878Sfc1 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
1783 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1124 m above ground
0-6 km bulk shear
37 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
128 m²/s²
Significant tornado parameter
0.5
Supercell composite
2.0

Open this sounding in Storm Lab

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 29, 11:43 AM EDTMesoscale DiscussionSPCAlbany, Broome, Cayuga, Chemung, Chenango, Columbia and 26 more62 min
May 29, 12:01 PM EDTMesoscale DiscussionSPCAlbany, Broome, Chemung, Chenango, Columbia, Cortland and 19 more59 min
May 29, 12:26 PM EDTTornado WatchSPCAlbany, Clinton, Columbia, Dutchess, Essex, Franklin and 13 more8 hr
May 29, 1:03 PM EDTSevere Thunderstorm WatchSPCBroome, Chemung, Chenango, Cortland, Delaware, Madison and 5 more8 hr
May 29, 1:25 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Cayuga, Chautauqua, Erie, Genesee and 13 more65 min
May 29, 1:52 PM EDTMesoscale DiscussionSPCAlbany, Clinton, Columbia, Essex, Franklin, Fulton and 8 more53 min
May 29, 2:13 PM EDTMesoscale DiscussionSPCBroome, Chemung, Chenango, Cortland, Delaware, Dutchess and 10 more62 min
May 29, 3:12 PM EDTMesoscale DiscussionSPCBroome, Cayuga, Chemung, Chenango, Cortland, Delaware and 12 more63 min
May 29, 3:26 PM EDTMesoscale DiscussionSPCAlbany, Clinton, Columbia, Essex, Franklin, Fulton and 11 more64 min
May 29, 4:40 PM EDTMesoscale DiscussionSPCBroome, Delaware, Otsego, Sullivan65 min
May 29, 5:54 PM EDTSevere Thunderstorm WatchSPCBronx, Kings, New York, Orange, Putnam, Queens and 3 more3 hr
May 29, 7:01 PM EDTMesoscale DiscussionSPCBronx, Kings, New York, Putnam, Richmond, Rockland and 1 more89 min
May 29, 7:21 PM EDTMesoscale DiscussionSPCDutchess54 min
May 29, 9:48 AM EDTMesoscale DiscussionSPCBelmont, Carroll, Columbiana, Coshocton, Fairfield, Guernsey and 18 more87 min
May 29, 4:22 PM EDTMesoscale DiscussionSPCBerkeley, Hampshire, Hardy, Jefferson, Morgan, Pendleton53 min
May 29, 4:33 PM EDTSevere Thunderstorm WatchSPCBerkeley, Grant, Hampshire, Hardy, Jefferson, Mineral and 2 more4 hr

Nearby

Severe Thunderstorm Watches in Pennsylvania, 2012Severe Thunderstorm Watches in New York, 2012Severe Thunderstorm Watches in Ohio, 2012Every severe thunderstorm watch in 2012

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.