Alert archive / Virginia / Mesoscale Discussions in 2011
Mesoscale Discussion 199
The Storm Prediction Center issued this mesoscale discussion at Mar 6, 2011, 8:04 PM EST for 18 counties in North Carolina; 27 counties in Virginia. It was in force for 56 min.
The area
The outline as issued.
The facts
- Issued
- Mar 6, 2011, 8:04 PM EST (01:04 UTC)
- Expired
- Mar 6, 2011, 9:00 PM EST
- In force
- 56 min
- Issued by
- the Storm Prediction Center
All 45 counties
Beaufort County, NC, Bertie County, NC, Camden County, NC, Chowan County, NC, Edgecombe County, NC, Gates County, NC, Greene County, NC, Halifax County, NC, Hertford County, NC, Martin County, NC, Nash County, NC, Northampton County, NC, Pasquotank County, NC, Perquimans County, NC, Pitt County, NC, Tyrrell County, NC, Washington County, NC, Wilson County, NC, Brunswick County, VA, Charles City County, VA, Chesterfield County, VA, City of Chesapeake, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Franklin, VA, City of Hampton, VA, City of Hopewell, VA, City of Newport News, VA, City of Norfolk, VA, City of Petersburg, VA, City of Poquoson, VA, City of Portsmouth, VA, City of Suffolk, VA, City of Virginia Beach, VA, City of Williamsburg, VA, Dinwiddie County, VA, Greensville County, VA, Isle of Wight County, VA, James City County, VA, Northampton County, VA, Prince George County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, York County, VA
The radar
The Norfolk radar (KAKQ), 86 km from the middle of the area, began a volume at 01:07 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
Newport, NC (KMHX), launched 00:00Z, 1.1 hours before the alert went out and 162 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
- 336 J/kg
- Mixed-layer CIN
- -11 J/kg
- Mixed-layer LCL
- 514 m above ground
- 0-6 km bulk shear
- 55 kt
- 0-1 km storm-relative helicity
- 314 m²/s²
- 0-3 km storm-relative helicity
- 317 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 2.2
The text
As transmitted, in the capitals the NWS used until 2016.
836 ACUS11 KWNS 070104 SWOMCD SPC MCD 070104 VAZ000-NCZ000-070200- MESOSCALE DISCUSSION 0199 NWS STORM PREDICTION CENTER NORMAN OK 0704 PM CST SUN MAR 06 2011 AREAS AFFECTED...SERN VA CONCERNING...TORNADO WATCH 41... VALID 070104Z - 070200Z THE SEVERE WEATHER THREAT FOR TORNADO WATCH 41 CONTINUES. STRONGLY FORCED SQUALL LINE...LIKELY DRIVEN BY/CORRELATED WITH UPPER VORT...IS PROGRESSING NEWD ACROSS NRN PORTIONS OF WW41 AT ROUGHLY 35KT. A NARROW WEDGE OF YET TO BE OVERTURNED MODIFIED WARM SECTOR REMAINS OVER EXTREME SERN VA WHERE A FEW HUNDRED J/KG MUCAPE EXISTS. JUST DOWNSTREAM...00Z SOUNDING FROM WAL EXHIBITS COOL/STABLE BOUNDARY LAYER AND IN THE ABSENCE OF SIGNIFICANT RECOVERY OVER THIS REGION THE APPROACHING SQUALL LINE SHOULD GRADUALLY WEAKEN. IN THE SHORT TERM...ISOLATED TORNADOES MAY YET STILL DEVELOP ALONG STRONGLY FORCED CONVECTIVE LINE...PRIMARILY OVER SERN VA. ..DARROW.. 03/07/2011 ...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT... ATTN...WFO...AKQ...MHX...RAH... LAT...LON 35437805 37397785 37407583 35447610 35437805
Nearby
Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in North Carolina, 2011Every mesoscale discussion in 2011
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.