Alert archive / Virginia / Mesoscale Discussions in 2004

Mesoscale Discussion 2232

September 17, 2004Charles County, Saint Mary's County, Maryland; 14 counties in North Carolina; 58 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Sep 17, 2004, 12:33 PM EDT for Charles County, Saint Mary's County, Maryland; 14 counties in North Carolina; 58 counties in Virginia. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued
Sep 17, 2004, 12:33 PM EDT (16:33 UTC)
Expired
Sep 17, 2004, 2:30 PM EDT
In force
117 min
Issued by
the Storm Prediction Center
All 74 counties

Charles County, MD, Saint Mary's County, MD, Beaufort County, NC, Bertie County, NC, Camden County, NC, Chowan County, NC, Craven County, NC, Gates County, NC, Hertford County, NC, Martin County, NC, Northampton County, NC, Pamlico County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC, Albemarle County, VA, Amherst County, VA, Buckingham County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Charlottesville, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Franklin, VA, City of Fredericksburg, VA, City of Hampton, VA, City of Hopewell, VA, City of Manassas, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Richmond, VA, City of Suffolk, VA, City of Waynesboro, VA, City of Williamsburg, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Madison County, VA, Mathews County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northumberland County, VA, Orange County, VA, Powhatan County, VA, Prince George County, VA, Prince William County, VA, Richmond County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 36 km from the middle of the area, began a volume at 16:33 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

Roanoke, VA (KRNK), launched 12:00Z, 4.6 hours before the alert went out and 192 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, Roanoke, VA at 12:00Z on 2004-09-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 266 joules per kilogram.LCLEL10008507005003002001001 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, Roanoke, VA at 12:00Z on 2004-09-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 346 square meters per square second.19395878Sfc1 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
266 J/kg
Mixed-layer CIN
0 J/kg
Mixed-layer LCL
534 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
346 m²/s²
0-3 km storm-relative helicity
493 m²/s²
Significant tornado parameter
0.6
Supercell composite
3.6

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
Sep 17, 1:15 PM EDTTornado WatchSPCAnne Arundel, Calvert, Charles, Prince George's, Saint Mary's7 hr
Sep 17, 3:33 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Carroll, Frederick, Harford, Howard and 1 more117 min
Sep 17, 3:50 PM EDTTornado WatchSPCAnne Arundel, Baltimore, Carroll, Frederick, Harford, Howard and 3 more4 hr
Sep 17, 3:53 PM EDTMesoscale DiscussionSPCCalvert, Charles, Prince George's, Saint Mary's2 hr
Sep 17, 6:19 PM EDTMesoscale DiscussionSPCAnne Arundel, Baltimore, Calvert, Carroll, Charles, Frederick and 6 more116 min
Sep 17, 6:50 PM EDTTornado WatchSPCAnne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 14 more5 hr
Sep 16, 8:45 PM EDTTornado WatchSPCCabarrus, Cleveland, Gaston, Lincoln, Mecklenburg, Polk and 1 more6 hr
Sep 16, 11:42 PM EDTMesoscale DiscussionSPCGaston, Mecklenburg2 hr
Sep 17, 1:51 AM EDTMesoscale DiscussionSPCAlexander, Burke, Caldwell, Catawba, Cleveland, Gaston and 6 more84 min
Sep 17, 9:26 AM EDTMesoscale DiscussionSPCAlamance, Anson, Bladen, Caswell, Chatham, Cumberland and 24 more2 hr
Sep 17, 10:10 AM EDTTornado WatchSPCAlamance, Anson, Bladen, Brunswick, Caswell, Chatham and 37 more7 hr
Sep 17, 11:03 AM EDTMesoscale DiscussionSPCAlamance, Bertie, Caswell, Chatham, Cumberland, Durham and 26 more87 min
Sep 17, 1:37 PM EDTMesoscale DiscussionSPCAlamance, Bladen, Brunswick, Caswell, Chatham, Columbus and 29 more113 min
Sep 17, 4:01 PM EDTMesoscale DiscussionSPCBladen, Brunswick, Columbus, Cumberland, Duplin, Franklin and 6 more59 min
Sep 17, 4:35 PM EDTTornado WatchSPCBladen, Brunswick, Columbus, Duplin, Edgecombe, Franklin and 14 more3 hr
Sep 17, 7:23 PM EDTMesoscale DiscussionSPCDuplin, Edgecombe, Greene, Halifax, Lenoir, Nash and 4 more37 min

Nearby

Mesoscale Discussions in Virginia, 2004Mesoscale Discussions in North Carolina, 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.