Alert archive / Pennsylvania / Mesoscale Discussions in 2004

Mesoscale Discussion 917

May 26, 2004Carroll County, Maryland; 26 counties in Pennsylvania

The Storm Prediction Center issued this mesoscale discussion at May 26, 2004, 5:15 PM EDT for Carroll County, Maryland; 26 counties in Pennsylvania. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 26, 2004, 5:15 PM EDT (21:15 UTC)
Expired
May 26, 2004, 7:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 27 counties

Carroll County, MD, Adams County, PA, Berks County, PA, Bradford County, PA, Carbon County, PA, Chester County, PA, Columbia County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Juniata County, PA, Lackawanna County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh 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, Union County, PA, Wyoming County, PA, York County, PA

The radar

The State College radar (KCCX), 125 km from the middle of the area, began a volume at 21:17 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 9.3 hours before the alert went out and 137 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, Phillips Aaf/Abe, MD at 12:00Z on 2004-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 101 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, Phillips Aaf/Abe, MD at 12:00Z on 2004-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 square meters per square second.1939587897Sfc1 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
101 J/kg
Mixed-layer CIN
-148 J/kg
Mixed-layer LCL
719 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
71 m²/s²
Significant tornado parameter
-0.0
Supercell composite
-0.1

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 25, 9:50 PM EDTMesoscale DiscussionSPCCalvert, Caroline, Dorchester, Queen Anne's, Saint Mary's, Somerset and 3 more55 min
May 26, 12:55 PM EDTMesoscale DiscussionSPCAllegany, Garrett95 min
May 26, 5:45 PM EDTSevere Thunderstorm WatchSPCAnne Arundel, Baltimore, Calvert, Carroll, Cecil, Charles and 11 more5 hr

Nearby

Mesoscale Discussions in Pennsylvania, 2004Mesoscale Discussions in Maryland, 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; radar from the NEXRAD Level II archive.