Alert archive / Virginia / Mesoscale Discussions in 2007

Mesoscale Discussion 1313

June 28, 20079 states

The Storm Prediction Center issued this mesoscale discussion at Jun 28, 2007, 7:30 PM EDT for 9 states. It was in force for 60 min.

The area

The outline as issued.

The facts

Issued: Jun 28, 2007, 7:30 PM EDT (23:30 UTC)
Expired: Jun 28, 2007, 8:30 PM EDT
In force: 60 min
Issued by: the Storm Prediction Center

All 223 counties

Kent County, DE, New Castle County, DE, Sussex County, DE, Allegany County, MD, 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, Alleghany County, NC, Ashe County, NC, Caldwell County, NC, Caswell County, NC, Forsyth County, NC, Granville County, NC, Guilford County, NC, Northampton County, NC, Person County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Warren County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, 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, Morris County, NJ, Ocean County, NJ, Passaic 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, Adams County, PA, Bedford County, PA, Berks County, PA, Bucks County, PA, Chester County, PA, Cumberland County, PA, Delaware County, PA, Franklin County, PA, Fulton County, PA, Lancaster County, PA, Montgomery County, PA, Philadelphia County, PA, York County, PA, Johnson County, TN, Accomack County, VA, Albemarle County, VA, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Arlington County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Carroll 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 Colonial Heights, VA, City of Covington, 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 Galax, VA, City of Hampton, VA, City of Harrisonburg, VA, City of Hopewell, VA, City of Lexington, 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 Radford, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Suffolk, VA, City of Waynesboro, VA, City of Williamsburg, VA, City of Winchester, VA, Clarke County, VA, Craig County, VA, Culpeper County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Floyd County, VA, Fluvanna County, VA, Franklin County, VA, Frederick County, VA, Giles County, VA, Gloucester County, VA, Goochland County, VA, Grayson County, VA, Greene County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, Henry County, VA, Highland 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, Montgomery County, VA, Nelson County, VA, New Kent County, VA, Northampton County, VA, Northumberland County, VA, Nottoway County, VA, Orange County, VA, Page County, VA, Patrick County, VA, Pittsylvania County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Prince William County, VA, Pulaski County, VA, Rappahannock County, VA, Richmond County, VA, Roanoke County, VA, Rockbridge County, VA, Rockingham County, VA, Shenandoah County, VA, Smyth County, VA, Southampton County, VA, Spotsylvania County, VA, Stafford County, VA, Surry County, VA, Sussex County, VA, Tazewell County, VA, Warren County, VA, Washington County, VA, Westmoreland County, VA, Wythe County, VA, York County, VA, Berkeley County, WV, Fayette County, WV, Grant County, WV, Greenbrier County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, McDowell County, WV, Mercer County, WV, Mineral County, WV, Monroe County, WV, Morgan County, WV, Nicholas County, WV, Pendleton County, WV, Pocahontas County, WV, Raleigh County, WV, Summers County, WV, Wyoming County, WV

The radar

The Sterling radar (KLWX), 77 km from the middle of the area, began a volume at 23:33 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, 11.5 hours before the alert went out and 79 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: 145 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 1265 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 59 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 282331
SWOMCD
SPC MCD 282330 
NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-NCZ000-DCZ000-WVZ000-TNZ000-290030-

MESOSCALE DISCUSSION 1313
NWS STORM PREDICTION CENTER NORMAN OK
0630 PM CDT THU JUN 28 2007

AREAS AFFECTED...SRN-SERN PA/NJ/DE/MD/MUCH OF VA/PARTS OF ERN AND
SERN WV/NRN NC

CONCERNING...SEVERE THUNDERSTORM WATCH 461...

VALID 282330Z - 290030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 461
CONTINUES.

ISOLATED STRONG WIND GUSTS AND SOME HAIL REMAIN A THREAT ACROSS THE
REMAINING PART OF WW 461...WHICH IS S AND SW OF A LINE FROM BEDFORD
COUNTY PA TO NRN NJ.  GIVEN THAT MUCH OF THE ACTIVITY S OF PA IS
DIURNALLY DRIVEN...SEVERE WEATHER THREAT MAY BEGIN TO WANE AFTER
SUNSET.

REGIONAL RADARS INDICATED A BROKEN LINE OF TSTMS EXTENDING SWWD FROM
THE VICINITY OF NYC THROUGH SERN TO SOUTH CENTRAL PA AND THEN
THROUGH NRN WV INTO THE OH VALLEY.  ADDITIONAL TSTMS...MORE WIDELY
SCATTERED...CONTINUE TO DEVELOP S OF THE PRIMARY CONVECTIVE LINE
FROM SRN WV EWD ACROSS MUCH OF VA AND NRN NC.  MODERATE INSTABILITY
EXTENDS FROM LONG ISLAND/NJ/FAR SERN PA INTO VA/NC WHICH WILL
SUPPORT ADDITIONAL TSTM DEVELOPMENT FOR THE NEXT SEVERAL HOURS.

STRONGEST WLY MID LEVEL WINDS EXTEND FROM PA TO SRN NEW ENGLAND
WHICH SUGGESTS GREATEST SEVERE THREAT DURING THE EARLY EVENING
SHOULD BE FROM SERN PA/NJ INTO LONG ISLAND WHERE EFFECTIVE BULK
SHEAR AT 30-35 KT WILL SUPPORT ADDITIONAL STORM ORGANIZATION.  COLD
POOLS SHOULD ALSO LOCALLY ENHANCE WIND GUST POTENTIAL.

FARTHER S INTO VA...WEAK MID LEVEL WINDS/SHEAR WILL RESULT IN MORE
PULSE STORMS THROUGH THE EARLY EVENING...WITH GREATEST SEVERE THREAT
EXPECTED TO BE OVER SERN VA INTO THE DELMARVA WHERE INSTABILITY
REMAINS MODERATE.

..PETERS.. 06/28/2007

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

ATTN...WFO...OKX...PHI...AKQ...CTP...LWX...RAH...RNK...PBZ...RLX...GSP...MRX...

37027541 36417731 36007984 35968168 36238206 37188199
38268095 38487993 39337933 40407858 40237763 40367616
41097444 40867358 39727363

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 27, 10:03 PM EDT	Mesoscale Discussion	SPC	New Castle	57 min
Jun 28, 12:52 PM EDT	Mesoscale Discussion	SPC	Kent, New Castle, Sussex	83 min
Jun 28, 2:07 PM EDT	Severe Thunderstorm Watch	SPC	Kent, New Castle, Sussex	8 hr
Jun 28, 2:54 PM EDT	Severe Thunderstorm Watch	SPC	Bergen, Essex, Hudson, Passaic, Union	6 hr
Jun 28, 4:04 PM EDT	Mesoscale Discussion	SPC	Bergen, Essex, Hudson, Hunterdon, Middlesex, Morris and 5 more	86 min
Jun 28, 12:37 AM EDT	Mesoscale Discussion	SPC	Clinton	53 min

Nearby

Mesoscale Discussions in Virginia, 2007 Mesoscale Discussions in Maryland, 2007 Mesoscale Discussions in New Jersey, 2007 Every mesoscale discussion in 2007

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.