Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 1770

July 10, 2003Montgomery County, Maryland; 39 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2003, 10:37 PM EDT for Montgomery County, Maryland; 39 counties in Virginia. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued: Jul 10, 2003, 10:37 PM EDT (02:37 UTC)
Expired: Jul 11, 2003, 12:00 AM EDT
In force: 83 min
Issued by: the Storm Prediction Center

All 40 counties

Montgomery County, MD, Albemarle County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Bedford County, VA, Buckingham County, VA, Campbell County, VA, City of Alexandria, VA, City of Charlottesville, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, VA, City of Roanoke, VA, City of Salem, VA, City of Waynesboro, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Greene County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA

The radar

The Sterling radar (KLWX), 129 km from the middle of the area, began a volume at 02:36 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

Washington/Dulle, VA (KIAD), launched 00:00Z, 2.6 hours before the alert went out and 132 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: 712 J/kg
Mixed-layer CIN: -21 J/kg
Mixed-layer LCL: 664 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 151 m²/s²
0-3 km storm-relative helicity: 242 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 2.6

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.

Issued	Product	Office	Counties	Lasted
Jul 11, 12:45 PM EDT	Mesoscale Discussion	SPC	Brunswick, Charles City, Dinwiddie, Greensville, Henrico, Isle of Wight and 10 more	2 hr
Jul 11, 4:10 PM EDT	Severe Thunderstorm Watch	SPC	Brunswick, Charles City, Chesterfield, Dinwiddie, Gloucester, Greensville and 32 more	4 hr
Jul 11, 6:34 PM EDT	Mesoscale Discussion	SPC	Greensville, Isle of Wight, Northampton, Southampton, York, City of Chesapeake and 9 more	86 min
Jul 11, 7:05 PM EDT	Severe Thunderstorm Watch	SPC	Isle of Wight, City of Chesapeake, City of Franklin, City of Norfolk, City of Portsmouth, City of Suffolk and 1 more	6 hr

Nearby

Mesoscale Discussions in Virginia, 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.