Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 2384

September 18, 2003Saint Mary's County, Somerset County, Worcester County, Maryland; 10 counties in North Carolina; 22 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2003, 12:03 PM EDT for Saint Mary's County, Somerset County, Worcester County, Maryland; 10 counties in North Carolina; 22 counties in Virginia. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: Sep 18, 2003, 12:03 PM EDT (16:03 UTC)
Expired: Sep 18, 2003, 2:00 PM EDT
In force: 117 min
Issued by: the Storm Prediction Center

All 35 counties

Saint Mary's County, MD, Somerset County, MD, Worcester County, MD, Camden County, NC, Chowan County, NC, Currituck County, NC, Dare County, NC, Gates County, NC, Hyde County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Washington County, NC, Accomack County, VA, City of Chesapeake, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Gloucester County, VA, Isle of Wight County, VA, James City County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northampton County, VA, Northumberland County, VA, Richmond County, VA, Surry County, VA, Westmoreland County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 93 km from the middle of the area, began a volume at 16:06 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 nearest sounding before it

Wallops Is Stn, VA (KWAL), launched 12:00Z, 4.1 hours before the alert went out and 152 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: 173 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 484 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 229 m²/s²
0-3 km storm-relative helicity: 266 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.0

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.

Issued	Product	Office	Counties	Lasted
Sep 18, 4:04 AM EDT	Mesoscale Discussion	SPC	Dorchester, Somerset, Wicomico, Worcester	3 hr
Sep 18, 7:44 AM EDT	Mesoscale Discussion	SPC	Calvert, Dorchester, Saint Mary's, Somerset, Talbot, Wicomico and 1 more	2 hr
Sep 18, 8:25 AM EDT	Tornado Watch	SPC	Saint Mary's, Somerset, Worcester	12 hr
Sep 18, 4:03 PM EDT	Mesoscale Discussion	SPC	Saint Mary's, Somerset, Wicomico, Worcester	117 min
Sep 18, 6:44 PM EDT	Mesoscale Discussion	SPC	Calvert, Charles, Dorchester, Saint Mary's, Somerset	91 min

Nearby

Mesoscale Discussions in Virginia, 2003 Mesoscale Discussions in North Carolina, 2003 Mesoscale Discussions in Maryland, 2003 Every mesoscale discussion in 2003

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.