Alert archive / Virginia / Mesoscale Discussions in 2016

Mesoscale Discussion 1328

July 19, 201648 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jul 19, 2016, 3:01 PM EDT for 48 counties in Virginia. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Jul 19, 2016, 3:01 PM EDT (19:01 UTC)
Expired
Jul 19, 2016, 4:00 PM EDT
In force
59 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 48 counties

Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Charlottesville, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Petersburg, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Fluvanna County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King William County, VA, Louisa County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nelson County, VA, New Kent County, VA, Nottoway County, VA, Orange County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Southampton County, VA, Spotsylvania County, VA, Surry County, VA, Sussex County, VA

The radar

The Norfolk radar (KAKQ), 111 km from the middle of the area, began a volume at 19:01 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, 7.0 hours before the alert went out and 146 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 2016-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 486 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, Roanoke, VA at 12:00Z on 2016-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
486 J/kg
Mixed-layer CIN
-115 J/kg
Mixed-layer LCL
1042 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 19, 3:32 PM EDTSevere Thunderstorm WatchSPCAmelia, Amherst, Appomattox, Bedford, Brunswick, Buckingham and 47 more5 hr
Jul 19, 6:17 PM EDTMesoscale DiscussionSPCAmelia, Appomattox, Brunswick, Campbell, Charles City, Charlotte and 36 more88 min

Nearby

Mesoscale Discussions in Virginia, 2016Every mesoscale discussion in 2016

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.