Alert archive / Virginia / Mesoscale Discussions in 2015

Mesoscale Discussion 950

June 8, 201510 counties in Maryland; 26 counties in Virginia; Jefferson County, West Virginia

The Storm Prediction Center issued this mesoscale discussion at Jun 8, 2015, 7:07 PM EDT for 10 counties in Maryland; 26 counties in Virginia; Jefferson County, West Virginia. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued: Jun 8, 2015, 7:07 PM EDT (23:07 UTC)
Expired: Jun 8, 2015, 8:00 PM EDT
In force: 53 min
Issued by: the Storm Prediction Center
Chance of a watch: 95%

All 37 counties

Anne Arundel County, MD, Baltimore County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Albemarle County, VA, Arlington 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 Manassas, VA, City of Manassas Park, VA, City of Waynesboro, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier 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, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Jefferson County, WV

The radar

The Sterling radar (KLWX), 49 km from the middle of the area, began a volume at 23:09 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 279Jun 8, 7:20 PM EDT

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 11.1 hours before the alert went out and 50 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: 1040 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 252 m²/s²
0-3 km storm-relative helicity: 249 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.

235 
ACUS11 KWNS 082307
SWOMCD
SPC MCD 082307 
MDZ000-DCZ000-VAZ000-WVZ000-090000-

MESOSCALE DISCUSSION 0950
NWS STORM PREDICTION CENTER NORMAN OK
0607 PM CDT MON JUN 08 2015

AREAS AFFECTED...NRN VA AND CENTRAL/NRN MD

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY 

VALID 082307Z - 090000Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A NEW SEVERE TSTM WATCH WILL BE COORDINATED AND ISSUED
SHORTLY FOR NRN VA INTO CENTRAL/NRN MD INCLUDING THE BALTIMORE AND
WASHINGTON D.C. METRO AREAS FOR A THREAT OF DAMAGING WINDS SPREADING
FROM WEST TO EAST ACROSS THIS REGION.

DISCUSSION...BANDS OF STORMS WILL CONTINUE TO MOVE FROM WEST TO EAST
ACROSS NRN VA AND CENTRAL/NRN MD THIS EVENING INTO AN ENVIRONMENT
THAT REMAINS MODERATELY UNSTABLE.  ALTHOUGH DEEP-LAYER SHEAR TENDS
TO DECREASE WITH SRN EXTENT...SUFFICIENT SHEAR WILL FAVOR A
CONTINUED THREAT FOR STRONG/DAMAGING WINDS AS HAVE ALREADY BEEN
OBSERVED AT KFDK WITH A WIND GUST OF 51 KT AT 2235Z.

..PETERS/EDWARDS.. 06/08/2015

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

ATTN...WFO...PHI...AKQ...LWX...

LAT...LON   37967919 39717752 39687612 39037635 38347687 38007764
            37817864 37967919

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 8, 1:10 PM EDT	Mesoscale Discussion	SPC	Allegany, Garrett	2 hr
Jun 8, 1:31 PM EDT	Mesoscale Discussion	SPC	Washington	119 min
Jun 8, 2:34 PM EDT	Tornado Watch	SPC	Allegany, Anne Arundel, Baltimore, Carroll, Charles, Frederick and 6 more	5 hr
Jun 8, 2:40 PM EDT	Severe Thunderstorm Watch	SPC	Garrett	6 hr
Jun 8, 4:46 PM EDT	Mesoscale Discussion	SPC	Baltimore, Carroll, Frederick, Harford, Howard, Montgomery and 3 more	59 min
Jun 8, 7:24 PM EDT	Severe Thunderstorm Watch	SPC	Anne Arundel, Baltimore, Carroll, Charles, Harford, Howard and 3 more	2 hr
Jun 8, 1:08 PM EDT	Mesoscale Discussion	SPC	Lee	97 min
Jun 8, 4:24 PM EDT	Mesoscale Discussion	SPC	Bland, Buchanan, Dickenson, Lee, Russell, Scott and 6 more	96 min
Jun 8, 6:24 PM EDT	Mesoscale Discussion	SPC	Amherst, Appomattox, Bedford, Bland, Buckingham, Campbell and 27 more	96 min

Nearby

Mesoscale Discussions in Virginia, 2015 Mesoscale Discussions in Maryland, 2015 Mesoscale Discussions in West Virginia, 2015 Every mesoscale discussion in 2015

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.