Alert archive / Maryland / Mesoscale Discussions in 2004

Mesoscale Discussion 1418

June 25, 20046 states

The Storm Prediction Center issued this mesoscale discussion at Jun 25, 2004, 1:08 PM EDT for 6 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jun 25, 2004, 1:08 PM EDT (17:08 UTC)
Expired: Jun 25, 2004, 3:15 PM EDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 54 counties

Kent County, DE, New Castle County, DE, Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Talbot County, MD, Washington County, MD, Burlington County, NJ, Camden County, NJ, Gloucester County, NJ, Hunterdon County, NJ, Mercer County, NJ, Salem County, NJ, Somerset County, NJ, Adams County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Montgomery County, PA, Philadelphia County, PA, York County, PA, Arlington County, VA, City of Alexandria, VA, City of Fairfax, VA, City of Falls Church, VA, City of Manassas, VA, City of Manassas Park, VA, City of Winchester, VA, Clarke County, VA, Fairfax County, VA, Frederick County, VA, Loudoun County, VA, Prince William County, VA, Berkeley County, WV, Hampshire County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV

The radar

The Sterling radar (KLWX), 85 km from the middle of the area, began a volume at 17:10 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.

Severe Thunderstorm Watch 521Jun 25, 1:45 PM EDT

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.1 hours before the alert went out and 80 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 375 J/kg
Mixed-layer CIN: -86 J/kg
Mixed-layer LCL: 1108 m above ground
0-6 km bulk shear: 37 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.4

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.

Issued	Product	Office	Counties	Lasted
Jun 25, 1:45 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle	7 hr
Jun 25, 4:14 PM EDT	Mesoscale Discussion	SPC	New Castle	2 hr
Jun 24, 8:10 PM EDT	Severe Thunderstorm Watch	SPC	Allegheny, Armstrong, Beaver, Blair, Butler, Cambria and 26 more	5 hr
Jun 24, 10:28 PM EDT	Mesoscale Discussion	SPC	Allegheny, Armstrong, Beaver, Blair, Butler, Cambria and 23 more	2 hr
Jun 25, 12:34 PM EDT	Mesoscale Discussion	SPC	Accomack, Brunswick, Charles City, Dinwiddie, Gloucester, Greensville and 29 more	116 min

Nearby

Mesoscale Discussions in Maryland, 2004 Mesoscale Discussions in Virginia, 2004 Mesoscale Discussions in Pennsylvania, 2004 Every 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.