Alert archive / Virginia / Mesoscale Discussions in 2016

Mesoscale Discussion 883

June 12, 201610 counties in North Carolina; 51 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 12, 2016, 3:03 PM EDT for 10 counties in North Carolina; 51 counties in Virginia. It was in force for 87 min.

The area

The outline as issued.

The facts

Issued
Jun 12, 2016, 3:03 PM EDT (19:03 UTC)
Expired
Jun 12, 2016, 4:30 PM EDT
In force
87 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 61 counties

Bertie County, NC, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Hertford County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Tyrrell County, NC, Amelia County, VA, Brunswick County, VA, Buckingham County, VA, Charles City County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, 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 Virginia Beach, VA, City of Williamsburg, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greensville 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, Lancaster County, VA, Louisa County, VA, Lunenburg County, VA, Mathews County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA

The radar

The Norfolk radar (KAKQ), 13 km from the middle of the area, began a volume at 19:06 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, 7.1 hours before the alert went out and 184 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, Wallops Is Stn, VA at 12:00Z on 2016-06-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 374 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, Wallops Is Stn, VA at 12:00Z on 2016-06-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 125 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
374 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
1853 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
125 m²/s²
0-3 km storm-relative helicity
97 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

407 
ACUS11 KWNS 121903
SWOMCD
SPC MCD 121903 
VAZ000-NCZ000-122030-

MESOSCALE DISCUSSION 0883
NWS STORM PREDICTION CENTER NORMAN OK
0203 PM CDT SUN JUN 12 2016

AREAS AFFECTED...SERN VA...FAR NERN NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 121903Z - 122030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...STRONG TO DAMAGING WIND POTENTIAL MAY INCREASE THIS
AFTERNOON IN ASSOCIATION WITH DEVELOPING THUNDERSTORMS ALONG AND
AHEAD OF A SWD MOVING COLD FRONT. MARGINALLY SEVERE HAIL IS ALSO
POSSIBLE. PARTS OF SERN VA AND FAR NERN NC ARE BEING MONITORED FOR A
SEVERE THUNDERSTORM WATCH.

DISCUSSION...STRONG HEATING HAS OCCURRED ACROSS THE VA TIDEWATER
REGION INTO NERN NC...WITH TEMPERATURES IN THE LOWER-MID 90S F
OBSERVED. THE AIR MASS HAS DESTABILIZED ALONG/AHEAD OF A WEAKLY
CONVERGENT COLD FRONT MOVING SWD ACROSS CNTRL VA...AND MLCAPE VALUES
ARE ESTIMATED AT 1500-2000 J/KG. VISIBLE SATELLITE TRENDS SHOW A
PRE-FRONTAL MID-LEVEL CU BAND MOVING SEWD ACROSS THE VA TIDEWATER.
SFC-BASED CU HAVE BEEN SLOWLY INCREASING IN VERTICAL DEVELOPMENT AND
COVERAGE CLOSER TO THE COLD FRONT...AND ISOLATED TSTMS ARE STILL
EXPECTED TO EVOLVE WITHIN THE NEXT COUPLE HRS ACROSS PORTIONS OF
E-CNTRL AND SERN VA.

WITH THE STEEPENING OF LOW-LEVEL LAPSE RATES SUPPORTED BY STRONG
DIURNAL HEATING/MIXING...AND THE DEVELOPMENT OF FAVORABLE INVERTED-V
LOW-LEVEL THERMODYNAMIC PROFILES...THE POTENTIAL FOR STRONG
DOWNBURST WINDS ACCOMPANYING CONVECTION SHOULD INCREASE THIS
AFTERNOON. ADDITIONALLY...12Z SOUNDINGS AND MORE RECENT VWP DATA
BOTH SAMPLED 20-30 KT W-NWLY FLOW ABOVE 1 KM AGL...AND DOWNWARD
MOMENTUM TRANSFER WILL ENHANCE CONVECTIVE WIND GUST POTENTIAL. THE
HAIL THREAT MAY BE MORE LIMITED BY WARM TEMPERATURES AND POOR LAPSE
RATES ALOFT...BUT MAY STILL ACCOMPANY ANY ORGANIZED STORM GIVEN
30-40 KT OF EFFECTIVE SHEAR PRESENT.

..ROGERS/WEISS.. 06/12/2016

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AKQ...MHX...LWX...RAH...RNK...

LAT...LON   37897595 36907571 35957577 35817643 36057708 36447787
            36907833 37457883 37997900 38067770 37897595

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 12, 7:20 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Chowan, Currituck, Dare and 16 more85 min

Nearby

Mesoscale Discussions in Virginia, 2016Mesoscale Discussions in North Carolina, 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.