Alert archive / Pennsylvania / Mesoscale Discussions in 2012

Mesoscale Discussion 1926

September 8, 201219 counties in New York; 24 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at Sep 8, 2012, 8:42 AM EDT for 19 counties in New York; 24 counties in Pennsylvania. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Sep 8, 2012, 8:42 AM EDT (12:42 UTC)
Expired
Sep 8, 2012, 10:15 AM EDT
In force
93 min
Issued by
the Storm Prediction Center
Chance of a watch
95%
All 43 counties

Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Herkimer County, NY, Jefferson County, NY, Lewis County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Oswego County, NY, Otsego County, NY, Schuyler County, NY, Seneca County, NY, Tioga County, NY, Tompkins County, NY, Wayne County, NY, Yates County, NY, Berks County, PA, Bradford County, PA, Carbon County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Juniata County, PA, Lackawanna County, PA, Lebanon County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wayne County, PA, Wyoming County, PA

The radar

The Binghamton radar (KBGM), 32 km from the middle of the area, began a volume at 12:42 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.

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Albany, NY (KALY), launched 12:00Z, 0.7 hours before the alert went out and 198 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 2012-09-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 113 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 2012-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 294 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
113 J/kg
Mixed-layer CIN
-168 J/kg
Mixed-layer LCL
869 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
294 m²/s²
0-3 km storm-relative helicity
397 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 8, 12:57 AM EDTMesoscale DiscussionSPCChautauqua2 hr
Sep 8, 10:03 AM EDTSevere Thunderstorm WatchSPCAllegany, Cattaraugus, Cayuga, Chemung, Franklin, Genesee and 16 more5 hr
Sep 8, 10:39 AM EDTMesoscale DiscussionSPCAlbany, Bronx, Columbia, Dutchess, Greene, Kings and 14 more2 hr
Sep 8, 11:18 AM EDTTornado WatchSPCBronx, Dutchess, Kings, Nassau, New York, Orange and 6 more10 hr
Sep 8, 11:38 AM EDTMesoscale DiscussionSPCAlbany, Broome, Chemung, Chenango, Cortland, Delaware and 18 more97 min
Sep 8, 12:40 PM EDTTornado WatchSPCAlbany, Broome, Chenango, Clinton, Columbia, Cortland and 22 more7 hr
Sep 8, 1:30 PM EDTMesoscale DiscussionSPCBronx, Dutchess, Kings, Nassau, New York, Putnam and 3 more60 min
Sep 8, 2:12 PM EDTMesoscale DiscussionSPCRichmond93 min
Sep 8, 2:46 PM EDTMesoscale DiscussionSPCAlbany, Clinton, Columbia, Delaware, Dutchess, Essex and 14 more59 min
Sep 8, 3:55 PM EDTMesoscale DiscussionSPCColumbia, Rensselaer, Washington65 min
Sep 8, 4:22 PM EDTMesoscale DiscussionSPCRichmond53 min
Sep 8, 6:17 PM EDTMesoscale DiscussionSPCSuffolk58 min
Sep 8, 5:00 AM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Bedford, Blair, Butler and 20 more60 min
Sep 8, 12:15 PM EDTSevere Thunderstorm WatchSPCAdams, Bedford, Berks, Blair, Bucks, Carbon and 29 more9 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2012Mesoscale Discussions in New York, 2012Every mesoscale discussion 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.