Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 902

May 25, 20046 states

The Storm Prediction Center issued this mesoscale discussion at May 25, 2004, 6:09 PM EDT for 6 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
May 25, 2004, 6:09 PM EDT (22:09 UTC)
Expired
May 25, 2004, 8:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 153 counties

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, Garrett 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, Salem County, NJ, Adams County, PA, Bedford County, PA, Berks County, PA, Blair County, PA, Bucks County, PA, Cambria County, PA, Chester County, PA, Cumberland County, PA, Dauphin County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Huntingdon County, PA, Juniata County, PA, Lancaster County, PA, Lebanon County, PA, Montgomery County, PA, Perry County, PA, Philadelphia County, PA, Somerset County, PA, York County, PA, Albemarle County, VA, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Carroll County, VA, Charlotte County, VA, Chesterfield County, VA, City of Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Covington, VA, City of Danville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Galax, VA, City of Harrisonburg, VA, City of Lexington, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, VA, City of Radford, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Cumberland County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Giles County, VA, Goochland County, VA, Grayson County, VA, Greene County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, Highland County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Loudoun County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Montgomery County, VA, Nelson County, VA, New Kent County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Richmond County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Smyth County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Wythe County, VA, Barbour County, WV, Berkeley County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mercer County, WV, Mineral County, WV, Monroe County, WV, Morgan County, WV, Pendleton County, WV, Pocahontas County, WV, Preston County, WV, Randolph County, WV, Summers County, WV, Tucker County, WV, Webster County, WV

The radar

The Sterling radar (KLWX), 74 km from the middle of the area, began a volume at 22:12 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.2 hours before the alert went out and 77 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 2004-05-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 19 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 2004-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 35 square meters per square second.193958Sfc1 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
19 J/kg
Mixed-layer CIN
-224 J/kg
Mixed-layer LCL
1534 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
35 m²/s²
0-3 km storm-relative helicity
46 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.

365 
ACUS11 KWNS 252209
SWOMCD
SPC MCD 252209 
NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-NCZ000-TNZ000-260015-

MESOSCALE DISCUSSION 0902
NWS STORM PREDICTION CENTER NORMAN OK
0509 PM CDT TUE MAY 25 2004

AREAS AFFECTED...S-CENTRAL/SERN PA...ERN WV PANHANDLE...MD...DC
METRO...NRN/WRN VA

CONCERNING...SEVERE THUNDERSTORM WATCH 287...

VALID 252209Z - 260015Z

CONTINUE WW.

AT 2145Z...CLUSTERS OF SEVERE THUNDERSTORMS WERE LOCATED ACROSS
S-CENTRAL PA/N-CENTRAL MD NEAR HGR...AND IN AN ARC FROM SHENANDOAH
COUNTY VA SSWWD ALONG THE VA/WV BORDER. EMBEDDED CELLS WERE TRACKING
GENERALLY ESEWD AT 20-25 KT.

AIR MASS IN ADVANCE OF ONGOING ACTIVITY WILL REMAIN VERY UNSTABLE
THROUGH THE NEXT FEW HOURS...WITH MID 60S TO NEAR 70 DEWPOINTS
CONTRIBUTING TO MUCAPE VALUES OF 3000-4000 J/KG. MESOSCALE COLD POOL
ASSOCIATED WITH SRN STORM CLUSTER SUGGESTS THAT THE THREAT FOR
DAMAGING WINDS MAY INCREASE THIS EVENING ACROSS CENTRAL VA. FURTHER
NORTH...SUPERCELL STORM NEAR WASHINGTON/FREDERICK COUNTY MD LINE
WILL CONTINUE ESEWD WITH THREAT OF LARGE HAIL AND PERHAPS ISOLATED
TORNADOES. AN ADDITIONAL WATCH MAY BE NEEDED EAST OF WW 287 FOR
PORTIONS OF ERN MD AND THE DELMARVA PENINSULA WITHIN AN HOUR OR SO.

..BANACOS.. 05/25/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PHI...AKQ...CTP...LWX...RAH...RNK...PBZ...RLX...MRX...

36507883 36528189 40597900 40577596 40437487 37827635

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 25, 7:25 PM EDTSevere Thunderstorm WatchSPCKent, New Castle, Sussex4 hr
May 25, 2:58 PM EDTMesoscale DiscussionSPCAllegany, Garrett, Washington92 min
May 25, 3:20 PM EDTSevere Thunderstorm WatchSPCAllegany, Carroll, Frederick, Garrett, Howard, Montgomery and 1 more6 hr
May 25, 12:54 PM EDTMesoscale DiscussionSPCAllegheny, Beaver, Crawford, Greene, Lawrence, Mercer and 1 more96 min
May 25, 1:30 PM EDTSevere Thunderstorm WatchSPCAllegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 6 more7 hr
May 25, 3:57 PM EDTMesoscale DiscussionSPCAllegheny, Armstrong, Beaver, Butler, Clarion, Fayette and 6 more63 min

Nearby

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