Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 876

May 9, 200363 counties in Virginia; 9 counties in West Virginia

The Storm Prediction Center issued this mesoscale discussion at May 9, 2003, 12:53 PM EDT for 63 counties in Virginia; 9 counties in West Virginia. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
May 9, 2003, 12:53 PM EDT (16:53 UTC)
Expired
May 9, 2003, 3:30 PM EDT
In force
3 hr
Issued by
the Storm Prediction Center
All 72 counties

Albemarle County, VA, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Augusta County, VA, Bath County, VA, Bedford County, VA, Botetourt County, VA, Buckingham County, VA, Campbell County, VA, Caroline County, VA, Charles City County, VA, Chesterfield County, VA, City of Buena Vista, VA, City of Charlottesville, VA, City of Colonial Heights, VA, City of Covington, VA, City of Fredericksburg, VA, City of Hopewell, VA, City of Lexington, VA, City of Lynchburg, VA, City of Petersburg, VA, City of Richmond, VA, City of Roanoke, VA, City of Salem, VA, City of Staunton, VA, City of Waynesboro, VA, City of Williamsburg, VA, Craig County, VA, Cumberland County, VA, Dinwiddie County, VA, Essex County, VA, Fluvanna County, VA, Gloucester County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, Henrico County, VA, Highland County, VA, James City County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Louisa County, VA, Mathews County, VA, Middlesex County, VA, Nelson County, VA, New Kent County, VA, Nottoway County, VA, Orange County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Richmond County, VA, Roanoke County, VA, Rockbridge County, VA, Spotsylvania County, VA, Surry County, VA, Sussex County, VA, Westmoreland County, VA, York County, VA, Fayette County, WV, Greenbrier County, WV, Monroe County, WV, Nicholas County, WV, Pocahontas County, WV, Raleigh County, WV, Summers County, WV, Webster County, WV, Wyoming County, WV

The radar

The Roanoke radar (KFCX), 135 km from the middle of the area, began a volume at 16:54 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.

The nearest sounding before it

Roanoke, VA (KRNK), launched 12:00Z, 4.9 hours before the alert went out and 74 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, Roanoke, VA at 12:00Z on 2003-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 59 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, Roanoke, VA at 12:00Z on 2003-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 153 square meters per square second.19395878Sfc1 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
59 J/kg
Mixed-layer CIN
-186 J/kg
Mixed-layer LCL
982 m above ground
0-6 km bulk shear
47 kt
0-1 km storm-relative helicity
153 m²/s²
0-3 km storm-relative helicity
199 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.

729 
ACUS11 KWNS 091654
SWOMCD
SPC MCD 091653 
VAZ000-MDZ000-WVZ000-091930-

MESOSCALE DISCUSSION 0876
NWS STORM PREDICTION CENTER NORMAN OK
1153 AM CDT FRI MAY 09 2003

AREAS AFFECTED...WV AND VA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 091653Z - 091930Z

...THUNDERSTORMS WILL DEVELOP/MOVE EWD ACROSS WV/VA THIS AFTERNOON. 
WW MAY BE REQUIRED...

REGIONAL RADAR DATA SUGGESTS SLOWER-MOVING PORTION OF MCS WILL SAG
SWD ACROSS WV AND CENTRAL VA THIS AFTERNOON.  WLY LOW-MID LEVEL
TRAJECTORIES SHOULD MAINTAIN AT LEAST WEAK WARM ADVECTION ACROSS
THIS REGION MAINTAINING CURRENT BAND OF CLOUDINESS/PRECIPITATION. 
ALONG SRN PORTION OF THIS GRADIENT...BOUNDARY LAYER WILL CONTINUE TO
WARM/DESTABILIZE WITH SBCAPES EXPECTED TO INCREASE ABOVE 2000 J/KG. 
GIVEN DEEP WLY COMPONENT AND SUFFICIENT CLOUD LAYER SHEAR...DAMAGING
WINDS MAY ACCOMPANY STRONGER STORMS ALONG SRN PERIPHERY...IN
ADDITION TO LARGE HAIL.

..DARROW.. 05/09/2003

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

ATTN...WFO...AKQ...LWX...RNK...RLX...

38528067 38257672 37337604 36877714 37168021 37758202

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 9, 2:05 PM EDTTornado WatchSPCAlbemarle, Alleghany, Amelia, Amherst, Appomattox, Augusta and 58 more6 hr
May 9, 3:55 PM EDTMesoscale DiscussionSPCAlbemarle, Alleghany, Amelia, Amherst, Appomattox, Bath and 78 more2 hr
May 9, 4:15 PM EDTTornado WatchSPCBrunswick, Greensville, Halifax, Lunenburg, Mecklenburg, Southampton and 6 more6 hr
May 9, 7:35 PM EDTSevere Thunderstorm WatchSPCBuchanan, Dickenson, Lee, Russell, Scott, Washington and 2 more5 hr
May 9, 5:36 PM EDTMesoscale DiscussionSPCBraxton, Calhoun, Gilmer, Jackson, Lewis, Pleasants and 4 more114 min
May 9, 6:00 PM EDTSevere Thunderstorm WatchSPCBoone, Braxton, Cabell, Calhoun, Clay, Doddridge and 21 more5 hr

Nearby

Mesoscale Discussions in Virginia, 2003Mesoscale Discussions in West Virginia, 2003Every mesoscale discussion in 2003

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.