Alert archive / Virginia / Mesoscale Discussions in 2004
Mesoscale Discussion 1321
The Storm Prediction Center issued this mesoscale discussion at Jun 17, 2004, 7:37 PM EDT for 7 states. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Jun 17, 2004, 7:37 PM EDT (23:37 UTC)
- Expired
- Jun 17, 2004, 8:30 PM EDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
All 104 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, Washington County, MD, Wicomico County, MD, Atlantic 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, Salem County, NJ, Somerset County, NJ, Union County, NJ, Warren County, NJ, Kings County, NY, Nassau County, NY, New York County, NY, Queens County, NY, Richmond County, NY, Adams County, PA, Berks County, PA, Bucks County, PA, Carbon County, PA, Chester County, PA, Delaware County, PA, Lancaster County, PA, Lebanon County, PA, Lehigh County, PA, Montgomery County, PA, Northampton County, PA, Philadelphia County, PA, York County, PA, Arlington County, VA, Caroline County, VA, Charles City County, VA, City of Alexandria, VA, City of Colonial Heights, VA, City of Fairfax, VA, City of Falls Church, VA, City of Fredericksburg, VA, City of Hopewell, VA, City of Manassas, VA, City of Manassas Park, VA, City of Petersburg, VA, City of Richmond, VA, City of Winchester, VA, Clarke County, VA, Culpeper County, VA, Essex County, VA, Fairfax County, VA, Fauquier County, VA, Frederick County, VA, Hanover County, VA, Henrico County, VA, King and Queen County, VA, King George County, VA, King William County, VA, Lancaster County, VA, Loudoun County, VA, Louisa County, VA, Madison County, VA, Middlesex County, VA, New Kent County, VA, Northumberland County, VA, Orange County, VA, Prince George County, VA, Prince William County, VA, Rappahannock County, VA, Richmond County, VA, Shenandoah County, VA, Spotsylvania County, VA, Stafford County, VA, Warren County, VA, Westmoreland County, VA, Berkeley County, WV, Jefferson County, WV
The radar
The Philadelphia radar (KDIX), 113 km from the middle of the area, began a volume at 23:36 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
Phillips Aaf/Abe, MD (KAPG), launched 12:00Z, 11.6 hours before the alert went out and 57 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.
- Mixed-layer CAPE
- 456 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 655 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 16 m²/s²
- 0-3 km storm-relative helicity
- 55 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
087 ACUS11 KWNS 172337 SWOMCD SPC MCD 172337 NYZ000-NJZ000-PAZ000-DEZ000-MDZ000-VAZ000-DCZ000-WVZ000-180030- MESOSCALE DISCUSSION 1321 NWS STORM PREDICTION CENTER NORMAN OK 0637 PM CDT THU JUN 17 2004 AREAS AFFECTED...ERN PA/NJ/DE/MD/PORTIONS OF NRN-ERN VA CONCERNING...SEVERE THUNDERSTORM WATCH 488... VALID 172337Z - 180030Z DAMAGING WINDS REMAIN THE PRIMARY THREAT WITH STORMS MOVING EWD ACROSS THE VALID PORTIONS OF WW 488. VAD WINDS FROM PA/NJ SWD ACROSS MD INDICATE 40-50 KT OF WLY MID-LEVEL FLOW WILL CONTINUE TO SUPPORT DEEP LAYER SHEAR VALUES FOR AN ORGANIZED SEVERE THREAT. DAMAGING WINDS SHOULD BE THE PRIMARY THREAT WITH ONGOING STORMS AND ANY NEW STORMS THAT DEVELOP ACROSS THIS REGION IN THE NEXT FEW HOURS. DEEP UNI-DIRECTIONAL WLY FLOW FROM JUST OFF THE SURFACE WILL FAVOR LINE SEGMENTS...WITH REGIONAL RADARS SHOWING A SMALL BOW ECHO MOVING ESE AT 40 KT INTO CENTRAL NJ POSING THE GREATEST WIND DAMAGE POTENTIAL ATTM. A GREATER THREAT FOR SUPERCELLS IS EXPECTED ACROSS THE SRN PORTIONS OF WW 488 FROM MD/ERN VA AND EWD TO THE COAST DURING THE NEXT 2-3 HOURS AS THIS REGION REMAINS CLOSER TO STRONGER INSTABILITY /MLCAPE 2000-3000 J/KG/. A CLUSTER OF STRONG TO SEVERE STORMS MOVING ESEWD INTO THE ERN WV PANHANDLE WILL POSE A SEVERE THREAT ACROSS SWRN PORTION OF WW 488...IF THEY CAN MAINTAIN THEIR INTENSITY AS THEY MOVE INTO FAR NRN VA BETWEEN 00-01Z. ..PETERS.. 06/17/2004 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...OKX...PHI...AKQ...CTP...LWX... 41047557 40787356 39727278 37077736 39167882 40507646
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 17, 2:35 PM EDT | Severe Thunderstorm Watch | SPC | Kent, New Castle, Sussex | 6 hr |
| Jun 17, 4:22 PM EDT | Mesoscale Discussion | SPC | Kent, New Castle | 83 min |
| Jun 17, 12:05 PM EDT | Mesoscale Discussion | SPC | Allegheny, Armstrong, Beaver, Blair, Bradford, Butler and 33 more | 115 min |
| Jun 17, 1:45 PM EDT | Severe Thunderstorm Watch | SPC | Allegheny, Armstrong, Beaver, Bedford, Blair, Bradford and 40 more | 6 hr |
Nearby
Mesoscale Discussions in Virginia, 2004Mesoscale Discussions in Maryland, 2004Mesoscale Discussions in New Jersey, 2004Every mesoscale discussion in 2004
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.