Alert archive / Virginia / Mesoscale Discussions in 2003

Mesoscale Discussion 2292

August 27, 20035 states

The Storm Prediction Center issued this mesoscale discussion at Aug 27, 2003, 6:56 PM EDT for 5 states. It was in force for 64 min.

The area

The outline as issued.

The facts

Issued
Aug 27, 2003, 6:56 PM EDT (22:56 UTC)
Expired
Aug 27, 2003, 8:00 PM EDT
In force
64 min
Issued by
the Storm Prediction Center
All 52 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, Wicomico County, MD, Worcester County, MD, Camden County, NJ, Cumberland County, NJ, Gloucester County, NJ, Salem County, NJ, Adams County, PA, Accomack County, VA, 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, Culpeper County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Greene County, VA, King George County, VA, Madison County, VA, Northumberland County, VA, Orange County, VA, Prince William County, VA, Richmond County, VA, Spotsylvania County, VA, Stafford County, VA, Westmoreland County, VA

The radar

The Sterling radar (KLWX), 39 km from the middle of the area, began a volume at 22:58 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

Washington/Dulle, VA (KIAD), launched 12:00Z, 10.9 hours before the alert went out and 31 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, Washington/Dulle, VA at 12:00Z on 2003-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 483 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, Washington/Dulle, VA at 12:00Z on 2003-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 66 square meters per square second.193958Sfc1 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
483 J/kg
Mixed-layer CIN
-236 J/kg
Mixed-layer LCL
1264 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
66 m²/s²
0-3 km storm-relative helicity
71 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.

566 
ACUS11 KWNS 272256
SWOMCD
SPC MCD 272256 
NJZ000-DEZ000-MDZ000-VAZ000-PAZ000-DCZ000-280000-

MESOSCALE DISCUSSION 2292
NWS STORM PREDICTION CENTER NORMAN OK
0556 PM CDT WED AUG 27 2003

AREAS AFFECTED...NRN/ERN VA...SERN PA...MD...DE...SRN NJ

CONCERNING...SEVERE THUNDERSTORM WATCH 902...

VALID 272256Z - 280000Z

A NEW WW MAY BE NEEDED EAST OF WW 902 AS INTENSIFYING LINE OF
STRONG-SEVERE THUNDERSTORMS EXTENDING FROM VA NWD INTO NRN MD AND
FAR SCENTRAL PA CONTINUES MOVING EWD.

STRONG COLD POOL WITH PRESSURE RISES AROUND 5 MB/2 HRS SHOULD
SUPPORT STRONG INFLOW INTO CONVECTIVE LINE. CONVECTIVE LINE WILL
CONTINUE TO MOVE ESEWD FROM 35-40 KTS OVER THE NEXT FEW
HOURS...WHICH WILL TAKE THE SEVERE THREAT TO THE NERN EDGE OF WW 902
BY 2330Z. CURRENT OBSERVATIONS AND OBJECTIVE ANALYSIS FIELDS AHEAD
OF CONVECTIVE LINE INDICATE THAT THE INTENSITY OF THE LINE SHOULD
MAINTAIN ITSELF AND POSSIBLY STRENGTHEN AS IT PROGRESSES EWD THROUGH
THE REMAINDER OF NRN/ERN VA CENTRAL/SRN MD WHERE AN AXIS OF MLCAPES
FROM 2500-3500 J/KG EXISTS. SOME UNCERTAINTY REMAINS WITH HOW LONG
THE SEVERE THREAT WITH THIS LINE WILL LAST WITH ONSET OF NOCTURNAL
BOUNDARY LAYER COOLING AND EFFECTS OF COOLER OCEAN WATER.

..CROSBIE.. 08/27/2003

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

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

38137883 39027764 39907726 39837479 37667533

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 27, 9:23 AM EDTMesoscale DiscussionSPCKent, Sussex2 hr
Aug 27, 7:30 PM EDTSevere Thunderstorm WatchSPCKent, New Castle, Sussex4 hr
Aug 26, 9:20 PM EDTSevere Thunderstorm WatchSPCAllegany, Garrett6 hr
Aug 26, 10:18 PM EDTMesoscale DiscussionSPCAllegany, Garrett57 min
Aug 27, 12:22 AM EDTMesoscale DiscussionSPCCharles53 min
Aug 27, 6:11 AM EDTMesoscale DiscussionSPCAllegany, Garrett, Washington2 hr
Aug 27, 9:40 AM EDTSevere Thunderstorm WatchSPCHarford5 hr
Aug 27, 10:35 AM EDTSevere Thunderstorm WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more5 hr
Aug 27, 2:10 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 8 more65 min
Aug 27, 3:09 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Frederick and 7 more66 min
Aug 27, 3:30 PM EDTSevere Thunderstorm WatchSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 9 more7 hr
Aug 27, 5:03 PM EDTMesoscale DiscussionSPCAllegany, Anne Arundel, Baltimore, Calvert, Carroll, Charles and 10 more87 min
Aug 27, 11:48 AM EDTMesoscale DiscussionSPCAdams, Allegheny, Beaver, Bedford, Cambria, Columbia and 18 more87 min
Aug 27, 2:05 PM EDTSevere Thunderstorm WatchSPCFayette, Greene, Washington, Westmoreland5 hr

Nearby

Mesoscale Discussions in Virginia, 2003Mesoscale Discussions in Maryland, 2003Mesoscale Discussions in New Jersey, 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.