Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 1244

June 22, 20127 states

The Storm Prediction Center issued this mesoscale discussion at Jun 22, 2012, 6:42 PM EDT for 7 states. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued: Jun 22, 2012, 6:42 PM EDT (22:42 UTC)
Expired: Jun 22, 2012, 7:45 PM EDT
In force: 63 min
Issued by: the Storm Prediction Center

All 158 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Cecil County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Harford County, MD, Howard County, MD, Kent County, MD, Montgomery County, MD, Prince George's County, MD, Queen Anne's County, MD, Saint Mary's County, MD, Somerset County, MD, Talbot County, MD, Washington County, MD, Wicomico County, MD, Worcester County, MD, Atlantic County, NJ, Bergen County, NJ, Burlington County, NJ, Camden County, NJ, Cape May County, NJ, Cumberland County, NJ, Essex County, NJ, Gloucester County, NJ, Hudson County, NJ, Hunterdon County, NJ, Mercer County, NJ, Middlesex County, NJ, Monmouth County, NJ, Ocean County, NJ, Salem County, NJ, Somerset County, NJ, Union County, NJ, Bronx County, NY, Kings County, NY, Nassau County, NY, New York County, NY, Queens County, NY, Richmond County, NY, Suffolk County, NY, Westchester County, NY, Adams County, PA, Bucks County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Montgomery County, PA, Philadelphia County, PA, York County, PA, Accomack County, VA, Albemarle County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta 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 Alexandria, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Danville, VA, City of Emporia, VA, City of Fairfax, VA, City of Falls Church, VA, City of Franklin, VA, City of Fredericksburg, VA, City of Hampton, VA, City of Harrisonburg, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Manassas, VA, City of Manassas Park, VA, City of Martinsville, 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 Staunton, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Waynesboro, VA, City of Williamsburg, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Gloucester County, VA, Goochland County, VA, Greene County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, Isle of Wight County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Louisa County, VA, Lunenburg County, VA, Madison County, VA, Mathews County, VA, Mecklenburg County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Page County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Rockingham County, VA, Shenandoah County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Warren County, VA, Westmoreland County, VA, York County, VA, Berkeley County, WV, Jefferson County, WV

The radar

The Sterling radar (KLWX), 58 km from the middle of the area, began a volume at 22:45 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.7 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: 243 J/kg
Mixed-layer CIN: -153 J/kg
Mixed-layer LCL: 1563 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: -24 m²/s²
0-3 km storm-relative helicity: 115 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.2

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

655 
ACUS11 KWNS 222242
SWOMCD
SPC MCD 222242 
RIZ000-CTZ000-NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-NCZ000-DCZ000-WVZ000-222345-

MESOSCALE DISCUSSION 1244
NWS STORM PREDICTION CENTER NORMAN OK
0542 PM CDT FRI JUN 22 2012

AREAS AFFECTED...MUCH OF VA...MD...NJ...SERN PA...NY METRO AND LONG
ISLAND...SRN NEW ENGLAND

CONCERNING...SEVERE THUNDERSTORM WATCH 417...418...

VALID 222242Z - 222345Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
417...418...CONTINUES.

SUMMARY...SEVERE THUNDERSTORMS CAPABLE OF DMGG WINDS AND HAIL ARE
EXPECTED TO PROGRESS OFFSHORE OF PORTIONS OF NEW ENGLAND...NY AND
NJ...WHILE STORMS FARTHER S WILL SLOWLY WEAKEN AFTER DARK.

DISCUSSION...SEVERAL LINES OF CONVECTION CONTINUE ACROSS PORTIONS OF
THE MID-ATLANTIC AND NORTHEAST...ALONG A CONGLOMERATION OF
BOUNDARIES INCLUDING A SEWD SAGGING COLD FRONT...A PREFRONTAL
TROUGH...SEA BREEZES...AND A SERIES OF OUTFLOWS. CONVECTION APPEARS
TO BE WEAKENING SIGNIFICANTLY ACROSS PORTIONS OF SRN NEW
ENGLAND...WHERE RAIN-COOLING HAS EFFECTIVELY STABILIZED MUCH OF THE
AREA. THE COLD FRONT IS EXPECTED THE QUICKLY PROGRESS OFFSHORE OF
SRN NEW ENGLAND...NY AND NJ...AND THE WW MAY BE CANCELLED FOLLOWING
ITS PASSAGE. FARTHER S ACROSS MD AND VA...ALTHOUGH NOCTURNAL COOLING
WILL BEGIN TO GRADUALLY STABILIZE THE BOUNDARY LAYER...THE AMBIENT
HOT AND MOIST AIR MASS MAY SOMEWHAT DELAY STRONGER CONVECTIVE
INHIBITION IN ADVANCE OF THE COLD FRONT...ALLOWING STRONG TO SEVERE
SURFACE-BASED STORMS TO CONTINUE FOR A FEW HOURS AFTER DARK.

..HURLBUT.. 06/22/2012

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

ATTN...WFO...BOX...OKX...PHI...AKQ...CTP...LWX...RNK...

LAT...LON   36538004 36818005 36997957 37467939 38007941 38137947
            38947868 39507809 39957706 40147587 41597294 41677171
            40727261 40457379 38957457 37997514 36537589 36538004

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 22, 12:18 PM EDT	Mesoscale Discussion	SPC		2 hr
Jun 22, 1:41 PM EDT	Severe Thunderstorm Watch	SPC	Greater Bridgeport Planning Region, Capitol Planning Region, Northwest Hills Planning Region, Lower Connecticut River Valley Planning Region, Naugatuck Valley Planning Region, Southeastern Connecticut Planning Region and 1 more	7 hr
Jun 22, 4:33 PM EDT	Mesoscale Discussion	SPC		87 min
Jun 22, 2:12 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	7 hr
Jun 22, 4:10 PM EDT	Mesoscale Discussion	SPC	Kent, Sussex	2 hr

Nearby

Mesoscale Discussions in Virginia, 2012 Mesoscale Discussions in Maryland, 2012 Mesoscale Discussions in New Jersey, 2012 Every mesoscale discussion in 2012

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.