Alert archive / Virginia / Mesoscale Discussions in 2003
Mesoscale Discussion 2385
The Storm Prediction Center issued this mesoscale discussion at Sep 18, 2003, 4:03 PM EDT for 4 counties in Maryland; 6 counties in North Carolina; 18 counties in Virginia. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Sep 18, 2003, 4:03 PM EDT (20:03 UTC)
- Expired
- Sep 18, 2003, 6:00 PM EDT
- In force
- 117 min
- Issued by
- the Storm Prediction Center
All 28 counties
Saint Mary's County, MD, Somerset County, MD, Wicomico County, MD, Worcester County, MD, Camden County, NC, Chowan County, NC, Currituck County, NC, Gates County, NC, Pasquotank County, NC, Perquimans County, NC, Accomack County, VA, City of Chesapeake, VA, City of Hampton, VA, City of Newport News, VA, City of Norfolk, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Gloucester County, VA, Isle of Wight County, VA, Lancaster County, VA, Mathews County, VA, Middlesex County, VA, Northampton County, VA, Northumberland County, VA, York County, VA
The radar
The Norfolk radar (KAKQ), 80 km from the middle of the area, began a volume at 20:06 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
Wallops Is Stn, VA (KWAL), launched 12:00Z, 8.1 hours before the alert went out and 115 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
- 173 J/kg
- Mixed-layer CIN
- -2 J/kg
- Mixed-layer LCL
- 484 m above ground
- 0-6 km bulk shear
- 44 kt
- 0-1 km storm-relative helicity
- 229 m²/s²
- 0-3 km storm-relative helicity
- 266 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 1.0
The text
As transmitted, in the capitals the NWS used until 2016.
698 ACUS11 KWNS 182004 SWOMCD SPC MCD 182003 MDZ000-VAZ000-NCZ000-182200- MESOSCALE DISCUSSION 2385 NWS STORM PREDICTION CENTER NORMAN OK 0303 PM CDT THU SEP 18 2003 AREAS AFFECTED...NERN NC...ERN VA AND SRN MD CONCERNING...SEVERE THUNDERSTORM WATCH 925... VALID 182003Z - 182200Z TORNADO THREAT CONTINUES TO BE LIMITED. THOUGH AN ISOLATED TORNADO OR TWO WILL REMAIN POSSIBLE THE REST OF THE AFTERNOON FROM NERN NC THROUGH ERN VA AND SRN MD...IT APPEARS OVERALL THREAT WILL REMAIN MARGINAL. THIS AFTERNOON THE CENTER OF HURRICANE ISABEL HAS MOVED INLAND ONTO THE COASTAL PLAINS OF ERN NC. VERY STRONG LOW LEVEL SHEAR WITH LARGE LOW LEVEL HODOGRAPHS REMAINS N OF THE CENTER AS FAR N AS SRN MD. HOWEVER...THE DENSE OVERCAST AND WIDESPREAD RAIN HAS LIMITED FURTHER DESTABILIZATION. THE LOW LEVEL FLOW CONTINUES TO VEER TO ELY FROM NERN NC NWD THROUGH COASTAL VA AND SOME MID LEVEL DRY AIR IS BEGINNING TO ENTRAIN INTO THE NERN QUADRANT OF THE STORM. THIS MAY CONTRIBUTE TO SOME DESTABILIZATION...ESPECIALLY ACROSS ERN VA INTO SRN MD THROUGH EARLY EVENING WHERE RADAR HAS SHOWN A TENDENCY FOR A FEW DISCRETE CELLS TO DEVELOP. HOWEVER... ONSET OF NOCTURNAL COOLING WILL TEND TO OFFSET THE EFFECTS OF ANY LOW LEVEL THETA-E ADVECTION...AND AS A RESULT THERMODYNAMIC PROFILES WILL REMAIN VERY MARGINAL. ..DIAL.. 09/18/2003 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...MHX...LWX... 35977660 36747687 38287662 38407539 37887512 36217558
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 18, 4:04 AM EDT | Mesoscale Discussion | SPC | Dorchester, Somerset, Wicomico, Worcester | 3 hr |
| Sep 18, 7:44 AM EDT | Mesoscale Discussion | SPC | Calvert, Dorchester, Saint Mary's, Somerset, Talbot, Wicomico and 1 more | 2 hr |
| Sep 18, 8:25 AM EDT | Tornado Watch | SPC | Saint Mary's, Somerset, Worcester | 12 hr |
| Sep 18, 12:03 PM EDT | Mesoscale Discussion | SPC | Saint Mary's, Somerset, Worcester | 117 min |
| Sep 18, 6:44 PM EDT | Mesoscale Discussion | SPC | Calvert, Charles, Dorchester, Saint Mary's, Somerset | 91 min |
Nearby
Mesoscale Discussions in Virginia, 2003Mesoscale Discussions in North Carolina, 2003Mesoscale Discussions in Maryland, 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.