Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 853

May 8, 20035 states

The Storm Prediction Center issued this mesoscale discussion at May 8, 2003, 2:48 PM EDT for 5 states. It was in force for 117 min.

The area

The outline as issued.

The facts

Issued: May 8, 2003, 2:48 PM EDT (18:48 UTC)
Expired: May 8, 2003, 4:45 PM EDT
In force: 117 min
Issued by: the Storm Prediction Center

All 65 counties

Sussex County, DE, Allegany County, MD, Anne Arundel County, MD, Baltimore County, MD, Calvert County, MD, Caroline County, MD, Carroll County, MD, Charles County, MD, City of Baltimore, MD, Dorchester County, MD, Frederick County, MD, Garrett 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, Adams County, PA, Bedford County, PA, Fayette County, PA, Franklin County, PA, Fulton County, PA, Greene County, PA, Somerset County, PA, Washington County, PA, Arlington County, VA, Caroline County, VA, City of Alexandria, 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 Winchester, VA, Clarke County, VA, Culpeper County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, King George County, VA, Loudoun County, VA, Madison County, VA, Orange County, VA, Page County, VA, Prince William County, VA, Rappahannock County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Berkeley County, WV, Grant County, WV, Hampshire County, WV, Hardy County, WV, Jefferson County, WV, Mineral County, WV, Morgan County, WV, Preston County, WV

The radar

The Sterling radar (KLWX), 15 km from the middle of the area, began a volume at 18:49 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, 6.8 hours before the alert went out and 21 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: 203 J/kg
Mixed-layer CIN: -52 J/kg
Mixed-layer LCL: 820 m above ground
0-6 km bulk shear: 56 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 88 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.

713 
ACUS11 KWNS 081848
SWOMCD
SPC MCD 081848 
DEZ000-MDZ000-VAZ000-PAZ000-DCZ000-WVZ000-OHZ000-082045-

MESOSCALE DISCUSSION 0853
NWS STORM PREDICTION CENTER NORMAN OK
0148 PM CDT THU MAY 08 2003

AREAS AFFECTED...SRN PA...ERN VA AND MUCH OF MD

CONCERNING...SEVERE THUNDERSTORM WATCH 301...

VALID 081848Z - 082045Z

ISOLATED SEVERE THUNDERSTORMS WILL CONTINUE TO MOVE SEWD AND OUT OF
WW 301 INTO SERN VA AND THE SRN DELMARVA PENINSULA OVER THE NEXT
HOUR. WE WILL MONITOR THIS AREA FOR THE POTENTIAL FOR ANOTHER
WATCH...BUT LIMITED AREAL COVERAGE MAY PRECLUDE ANOTHER WATCH
ISSUANCE.

AIRMASS OVER ERN 2/3RDS OF THE WW 301 CONTINUES TO REMAIN COOL AND
STABLE AND THUS THE SEVERE THREAT APPEARS TO BE MINIMAL OVER THIS
AREA THROUGH THE REMAINDER OF THE WATCH TIME. OVER THE WRN 1/3 OF 
WW 301...SFC TEMPERATURES HAVE WARMED INTO THE UPPER 70S/LOWER 80S.
THIS AIRMASS WAS SUPPORTING 1000-1500 J/KG OF MLCAPE. LOW LEVEL MASS
CONVERGENCE ALONG AN INVERTED TROUGH TO THE NORTHWEST OF A SFC LOW
OFF THE SERN VA COAST WILL ALLOW FOR CONTINUE PROPAGATION OF
CONVECTION INTO SERN VA AND THE SRN DELMARVA. REGIONAL VWP/S OVER
SERN VA/SRN DELMARVA SUPPORT SUFFICIENT SHEAR FOR AN ISOLATED SEVERE
STORMS.

..CROSBIE.. 05/08/2003

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

ATTN...WFO...PHI...AKQ...CTP...LWX...PBZ...

38007776 40248079 40237740 38007444

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 8, 12:55 PM EDT	Severe Thunderstorm Watch	SPC	Sussex	5 hr
May 8, 4:46 PM EDT	Mesoscale Discussion	SPC	Allegany, Charles, Garrett, Saint Mary's	59 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; radar from the NEXRAD Level II archive.