Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 352

March 29, 20034 states

The Storm Prediction Center issued this mesoscale discussion at Mar 29, 2003, 12:01 PM EST for 4 states. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued: Mar 29, 2003, 12:01 PM EST (17:01 UTC)
Expired: Mar 29, 2003, 1:30 PM EST
In force: 89 min
Issued by: the Storm Prediction Center

All 56 counties

Baltimore County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Frederick County, MD, Howard County, MD, Montgomery County, MD, Prince George's County, MD, Washington County, MD, Adams County, PA, Cumberland County, PA, Dauphin County, PA, Franklin County, PA, Lancaster County, PA, Lebanon County, PA, Perry County, PA, York County, PA, Albemarle County, VA, Amherst County, VA, Arlington County, VA, Buckingham 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 Manassas, VA, City of Manassas Park, VA, City of Waynesboro, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Cumberland County, VA, Fairfax County, VA, Fauquier County, VA, Fluvanna County, VA, Frederick County, VA, Goochland County, VA, Greene County, VA, Hanover County, VA, King George County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Nelson County, VA, Orange County, VA, Page County, VA, Powhatan County, VA, Prince William County, VA, Rappahannock County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Berkeley County, WV, Jefferson County, WV

The nearest sounding before it

Washington/Dulle, VA (KIAD), launched 12:00Z, 5.0 hours before the alert went out and 24 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: 1 J/kg
Mixed-layer CIN: -71 J/kg
Mixed-layer LCL: 529 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 278 m²/s²
0-3 km storm-relative helicity: 284 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.

980 
ACUS11 KWNS 291702
SWOMCD
SPC MCD 291701 
PAZ000-MDZ000-VAZ000-DCZ000-WVZ000-291830-

MESOSCALE DISCUSSION 0352
NWS STORM PREDICTION CENTER NORMAN OK
1101 AM CST SAT MAR 29 2003

AREAS AFFECTED...CENTRAL/NRN VA...MD...SOUTH CENTRAL/SERN PA

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 291701Z - 291830Z

BROKEN LINE OF CONVECTION IS EXPECTED TO DEVELOP IN LEE OF THE
APPALACHIANS IN THE NEXT 2-3 HOURS.  WW MAY BE REQUIRED FOR
PORTIONS OF CENTRAL/NRN VA INTO CENTRAL PA.



LATEST SURFACE ANALYSIS PLACES A COLD FRONT FROM CENTRAL PA SWWD
INTO FAR WRN VA TO ALONG THE VA/WV BORDER.  THE AIR MASS EAST OF
THIS FRONT HAS BEEN SLOWLY DESTABILIZING THROUGH THE MORNING...
ESPECIALLY IN THE VALLEYS OF WRN VA INTO SOUTH CENTRAL PA WHERE
MOSTLY CLEAR SKIES HAVE ALLOWED SURFACE TEMPERATURES TO RISE INTO
THE UPPER 60S TO MIDDLE 70S.  DESPITE CLOUDINESS FURTHER EAST...
MLCAPE VALUES ARE EXPECTED TO BE AROUND 1000 J/KG BY THIS
AFTERNOON IN ADVANCE OF THE COLD FRONT.  DEEP CONVERGENCE WITH
THE COLD FRONT WILL RESULT IN A BROKEN LINE OF THUNDERSTORMS AS
THE FRONT MOVES INTO THE UNSTABLE AIR MASS BETWEEN 18-21Z. 
SUFFICIENT DEEP LAYER SHEAR WILL SUPPORT ORGANIZED STORMS WITH
DAMAGING WINDS AND HAIL BEING THE PRIMARY THREATS.

..PETERS.. 03/29/2003

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

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

39727798 40667721 40437608 38667678 37497751 37277843
37597944

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 29, 4:33 PM EST	Mesoscale Discussion	SPC	Charles	117 min
Mar 29, 12:44 PM EST	Mesoscale Discussion	SPC	Greensville, Isle of Wight, James City, Southampton, Surry, Sussex and 4 more	91 min

Nearby

Mesoscale Discussions in Virginia, 2003 Mesoscale Discussions in Maryland, 2003 Mesoscale Discussions in Pennsylvania, 2003 Every 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.