Alert archive / Virginia / Mesoscale Discussions in 2009

Mesoscale Discussion 928

June 2, 20095 counties in Maryland; 9 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 2, 2009, 6:47 PM EDT for 5 counties in Maryland; 9 counties in Virginia. It was in force for 58 min.

The area

The outline as issued.

The facts

Issued: Jun 2, 2009, 6:47 PM EDT (22:47 UTC)
Expired: Jun 2, 2009, 7:45 PM EDT
In force: 58 min
Issued by: the Storm Prediction Center

Counties Calvert County, MD, Charles County, MD, Dorchester County, MD, Saint Mary's County, MD, Somerset County, MD, Caroline County, VA, City of Fredericksburg, VA, Essex County, VA, King George County, VA, Orange County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA

The radar

The Sterling radar (KLWX), 119 km from the middle of the area, began a volume at 22:49 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

Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 10.8 hours before the alert went out and 148 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1348 m above ground
0-6 km bulk shear: 30 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 63 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.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 2, 1:31 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 14 more	89 min
Jun 2, 1:58 PM EDT	Severe Thunderstorm Watch	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Cecil and 15 more	6 hr
Jun 2, 4:18 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Caroline, Cecil, Charles and 11 more	87 min

Nearby

Mesoscale Discussions in Virginia, 2009 Mesoscale Discussions in Maryland, 2009 Every mesoscale discussion in 2009

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.