Alert archive / Pennsylvania / Mesoscale Discussions in 2003

Mesoscale Discussion 949

May 11, 200320 counties in New York; 30 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 11, 2003, 3:54 PM EDT for 20 counties in New York; 30 counties in Pennsylvania. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 11, 2003, 3:54 PM EDT (19:54 UTC)
Expired
May 11, 2003, 6:00 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 50 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, Ontario County, NY, Oswego County, NY, Schuyler County, NY, Seneca County, NY, Steuben County, NY, Tioga County, NY, Tompkins County, NY, Wayne County, NY, Yates County, NY, Adams County, PA, Bedford County, PA, Blair County, PA, Bradford County, PA, Centre County, PA, Clinton County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Luzerne County, PA, Lycoming County, PA, Mifflin County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Potter County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Tioga County, PA, Union County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 104 km from the middle of the area, began a volume at 19:56 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 nearest sounding before it

Buffalo Intl Airport, NY (KBUF), launched 12:00Z, 7.9 hours before the alert went out and 203 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 2003-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 281 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 2003-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 square meters per square second.1939587897117Sfc1 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
281 J/kg
Mixed-layer CIN
-165 J/kg
Mixed-layer LCL
850 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
107 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

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
May 11, 10:07 AM EDTMesoscale DiscussionSPCAllegany, Broome, Cayuga, Chemung, Chenango, Cortland and 19 more113 min
May 11, 10:30 AM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Erie, Genesee, Orleans and 1 more2 hr
May 11, 11:45 AM EDTTornado WatchSPCAllegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 2 more5 hr
May 11, 12:32 PM EDTMesoscale DiscussionSPCBroome, Cayuga, Chemung, Chenango, Cortland, Jefferson and 13 more118 min
May 11, 1:50 PM EDTTornado WatchSPCBroome, Cayuga, Chemung, Chenango, Cortland, Herkimer and 14 more5 hr
May 11, 2:52 PM EDTMesoscale DiscussionSPCAllegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston and 3 more113 min

Nearby

Mesoscale Discussions in Pennsylvania, 2003Mesoscale Discussions in New York, 2003Every mesoscale discussion in 2003

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.