Alert archive / Virginia / Mesoscale Discussions in 2016

Mesoscale Discussion 948

June 16, 20164 states

The Storm Prediction Center issued this mesoscale discussion at Jun 16, 2016, 11:27 AM EDT for 4 states. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Jun 16, 2016, 11:27 AM EDT (15:27 UTC)
Expired: Jun 16, 2016, 12:30 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 55 counties

Allegany County, MD, Charles County, MD, Frederick County, MD, Garrett County, MD, Montgomery County, MD, Washington County, MD, Fayette County, PA, Greene County, PA, Albemarle County, VA, Arlington County, VA, Caroline 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 Harrisonburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Rockingham County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Marion County, WV, Mineral County, WV, Monongalia County, WV, Morgan County, WV, Pendleton County, WV, Preston County, WV, Taylor County, WV, Tucker County, WV

The radar

The Sterling radar (KLWX), 116 km from the middle of the area, began a volume at 15:27 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.

Severe Thunderstorm Watch 261Jun 16, 1:55 PM EDT

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 3.5 hours before the alert went out and 124 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: 248 J/kg
Mixed-layer CIN: -91 J/kg
Mixed-layer LCL: 689 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: -15 m²/s²
0-3 km storm-relative helicity: 17 m²/s²
Significant tornado parameter: -0.0
Supercell composite: -0.1

Open this sounding in Storm Lab

The text

As transmitted.

972 
ACUS11 KWNS 161527
SWOMCD
SPC MCD 161527 
VAZ000-MDZ000-DCZ000-WVZ000-PAZ000-161630-

MESOSCALE DISCUSSION 0948
NWS STORM PREDICTION CENTER NORMAN OK
1027 AM CDT THU JUN 16 2016

AREAS AFFECTED...SWRN PA / WRN MD / NRN AND ERN WV / NRN AND CNTRL
VA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 161527Z - 161630Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR THE
POSSIBILITY FOR A SEVERE THUNDERSTORM WATCH ACROSS PORTIONS OF THE
CNTRL APPALACHIANS AND OVER NRN VA E OF THE HIGHER TERRAIN.

DISCUSSION...SURFACE ANALYSIS INDICATES A STATIONARY FRONTAL ZONE
FROM THE DELMARVA NWWD NEAR THE POTOMAC RIVER INTO WRN PA.  THE
AIRMASS S OF THE BOUNDARY IS CONTINUING TO DESTABILIZE LATE THIS
MORNING WITH PATCHY CLOUD COVER.  N OF THE BOUNDARY...WEAK
CONVECTION AND ITS INCIPIENT CLOUD COVER OVER DE/NJ AND SERN PA HAVE
THWARTED DESTABILIZATION FARTHER N OVER CNTRL PA SEWD INTO DE/SRN
NJ.  

A BAND OF ELEVATED STORMS IS MOVING EWD ACROSS W-CNTRL PA AND WILL
MOVE INTO A MORE HOSTILE AIRMASS FOR VIGOROUS STORM DEVELOPMENT.  A
42-KT GUST WAS MEASURED AT KDUJ AROUND 15Z WITH THIS TSTM BAND. 
CURRENT THINKING IS ONLY A LOW RISK FOR WIND DAMAGE MAY EXIST WITH
THIS ACTIVITY IN THE SHORT TERM.  FARTHER SW...STORMS MAY BE
TRANSITIONING TO SURFACE-BASED...AND A CONTINUED RISK FOR ISOLD
LARGE HAIL MAY CONTINUE DURING THE NEXT FEW HOURS AS WELL AS AN
INCREASING THREAT FOR STRONG/LOW-END SEVERE GUSTS CAPABLE OF WIND
DAMAGE.  HOWEVER...THERE REMAINS UNCERTAINTY REGARDING ADDITIONAL
STORM DEVELOPMENT OVER NRN WV NEAR THE SWRN PA STORMS.  IF
ADDITIONAL STORMS DEVELOP...A SEVERE THUNDERSTORM WATCH WILL BE
CONSIDERED.  OTHERWISE...A SEVERE THUNDERSTORM WATCH WILL PROBABLY
NOT NEED TO BE CONSIDERED UNTIL LATER.

..SMITH/GOSS.. 06/16/2016

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

ATTN...WFO...AKQ...CTP...LWX...RNK...PBZ...RLX...

LAT...LON   39858023 39937961 39587747 38787683 37817724 37647849
            39628041 39858023

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 16, 1:08 PM EDT	Mesoscale Discussion	SPC	Allegany, Anne Arundel, Calvert, Carroll, Charles, Frederick and 7 more	97 min
Jun 16, 1:58 PM EDT	Severe Thunderstorm Watch	SPC	Allegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 9 more	8 hr
Jun 16, 4:20 PM EDT	Mesoscale Discussion	SPC	Allegany, Anne Arundel, Calvert, Carroll, Charles, Frederick and 6 more	55 min
Jun 16, 6:54 PM EDT	Mesoscale Discussion	SPC	Anne Arundel, Baltimore, Calvert, Carroll, Charles, Frederick and 7 more	96 min

Nearby

Mesoscale Discussions in Virginia, 2016 Mesoscale Discussions in West Virginia, 2016 Mesoscale Discussions in Maryland, 2016 Every 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.