Alert archive / Pennsylvania / Mesoscale Discussions in 2004

Mesoscale Discussion 559

May 2, 20045 states

The Storm Prediction Center issued this mesoscale discussion at May 2, 2004, 5:48 PM EDT for 5 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
May 2, 2004, 5:48 PM EDT (21:48 UTC)
Expired
May 2, 2004, 7:45 PM EDT
In force
117 min
Issued by
the Storm Prediction Center
All 51 counties

Baltimore County, MD, Carroll County, MD, Frederick County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Broome County, NY, Cayuga County, NY, Chemung County, NY, Chenango County, NY, Cortland County, NY, Lewis County, NY, Madison County, NY, Oneida County, NY, Onondaga County, NY, Oswego County, NY, Schuyler County, NY, Tioga County, NY, Tompkins County, NY, Adams County, PA, Bradford County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Lebanon County, PA, Lycoming County, PA, Montour County, PA, Northumberland County, PA, Perry County, PA, Schuylkill County, PA, Snyder County, PA, Sullivan County, PA, Susquehanna County, PA, Union County, PA, Wyoming County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Frederick County, VA, Loudoun County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 9.8 hours before the alert went out and 201 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, Washington/Dulle, VA at 12:00Z on 2004-05-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 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, Washington/Dulle, VA at 12:00Z on 2004-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 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
44 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
486 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
134 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 2, 1:21 PM EDTMesoscale DiscussionSPCAllegany, Frederick, Garrett, Washington114 min
May 2, 3:20 PM EDTSevere Thunderstorm WatchSPCAllegany, Frederick, Washington6 hr
May 2, 5:45 PM EDTSevere Thunderstorm WatchSPCCharles, Prince George's5 hr
May 2, 7:24 PM EDTMesoscale DiscussionSPCCharles, Prince George's2 hr
May 2, 6:54 PM EDTMesoscale DiscussionSPCDelaware, Orange, Sullivan, Ulster96 min

Nearby

Mesoscale Discussions in Pennsylvania, 2004Mesoscale Discussions in New York, 2004Mesoscale Discussions in Virginia, 2004Every mesoscale discussion in 2004

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.