Alert archive / Virginia / Mesoscale Discussions in 2012
Mesoscale Discussion 446
The Storm Prediction Center issued this mesoscale discussion at Apr 4, 2012, 1:31 PM EDT for 5 states. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- Apr 4, 2012, 1:31 PM EDT (17:31 UTC)
- Expired
- Apr 4, 2012, 3:00 PM EDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
All 168 counties
Bell County, KY, Breathitt County, KY, Clay County, KY, Elliott County, KY, Estill County, KY, Floyd County, KY, Harlan County, KY, Jackson County, KY, Johnson County, KY, Knott County, KY, Knox County, KY, Lawrence County, KY, Lee County, KY, Leslie County, KY, Letcher County, KY, Madison County, KY, Magoffin County, KY, Martin County, KY, Menifee County, KY, Morgan County, KY, Owsley County, KY, Perry County, KY, Pike County, KY, Powell County, KY, Wolfe County, KY, Alamance County, NC, Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Beaufort County, NC, Bertie County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Chowan County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gates County, NC, Granville County, NC, Greene County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Hertford County, NC, Iredell County, NC, Johnston County, NC, Lee County, NC, Lincoln County, NC, Martin County, NC, Mecklenburg County, NC, Mitchell County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Pitt County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Washington County, NC, Watauga County, NC, Wayne County, NC, Wilkes County, NC, Wilson County, NC, Yadkin County, NC, Yancey County, NC, Carter County, TN, Claiborne County, TN, Greene County, TN, Hancock County, TN, Hawkins County, TN, Johnson County, TN, Sullivan County, TN, Unicoi County, TN, Washington County, TN, Alleghany County, VA, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Bland County, VA, Botetourt County, VA, Brunswick County, VA, Buchanan County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, Chesterfield County, VA, City of Bristol, VA, City of Buena Vista, VA, City of Colonial Heights, VA, City of Covington, VA, City of Danville, VA, City of Emporia, VA, City of Franklin, VA, City of Galax, VA, City of Hopewell, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Newport News, VA, City of Norton, VA, City of Petersburg, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, City of Suffolk, VA, City of Williamsburg, VA, Craig County, VA, Cumberland County, VA, Dickenson County, VA, Dinwiddie County, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Greensville County, VA, Halifax County, VA, Henry County, VA, Isle of Wight County, VA, Lee County, VA, Lunenburg County, VA, Mecklenburg County, VA, Montgomery County, VA, Nottoway County, VA, Patrick County, VA, Pittsylvania County, VA, Prince Edward County, VA, Prince George County, VA, Pulaski County, VA, Roanoke County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Southampton County, VA, Surry County, VA, Sussex County, VA, Tazewell County, VA, Washington County, VA, Wise County, VA, Wythe County, VA, Boone County, WV, Lincoln County, WV, Logan County, WV, McDowell County, WV, Mercer County, WV, Mingo County, WV, Monroe County, WV, Raleigh County, WV, Summers County, WV, Wayne County, WV, Wyoming County, WV
The radar
The Roanoke radar (KFCX), 76 km from the middle of the area, began a volume at 17:33 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
Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 5.5 hours before the alert went out and 96 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
- 94 J/kg
- Mixed-layer CIN
- -189 J/kg
- Mixed-layer LCL
- 1161 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 167 m²/s²
- 0-3 km storm-relative helicity
- 146 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted, in the capitals the NWS used until 2016.
902
ACUS11 KWNS 041731
SWOMCD
SPC MCD 041731
NCZ000-VAZ000-WVZ000-TNZ000-KYZ000-041900-
MESOSCALE DISCUSSION 0446
NWS STORM PREDICTION CENTER NORMAN OK
1231 PM CDT WED APR 04 2012
AREAS AFFECTED...ERN KY...SRN WV...SRN/WRN VA...NRN/WRN NC...FAR
NERN TN
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 041731Z - 041900Z
SCATTERED THUNDERSTORMS ARE FORECAST TO DEVELOP DURING THE NEXT FEW
HRS ACROSS ERN KY...SRN WV...SRN/WRN VA...NRN/WRN NC AND FAR NERN
TN. THREAT FOR DAMAGING WINDS AND LARGE HAIL WILL ACCOMPANY THIS
ACTIVITY. AREA IS BEING MONITORED FOR A WW.
SURFACE ANALYSIS AT 17Z SHOWS A COLD FRONT SETTLING SWD INTO THE
CNTRL APPALACHIANS AND MID-ATLANTIC REGION. SURFACE AIRMASS ALONG
AND S OF THE FRONT IS WARMING INTO THE 70S...WHICH IS AIDING IN
RAPID BOUNDARY LAYER DESTABILIZATION. IN ADDITION...A MIDLEVEL
DISTURBANCE LOCATED OVER THE LWR OH VALLEY IS APPROACHING THE
REGION. ASCENT ASSOCIATED WITH THIS FEATURE COMBINED WITH
DESTABILIZING BOUNDARY LAYER AND DEVELOPMENT OF MODERATE INSTABILITY
WILL FAVOR AN INCREASE IN THUNDERSTORM COVERAGE ALONG/AHEAD OF THE
FRONT DURING THE AFTERNOON. AREA RESIDES ALONG THE SRN FRINGE OF
STRONGER MIDLEVEL W-NWLYS...WHICH YIELDS SUFFICIENT DEEP-LAYER WLY
SHEAR FOR E-SEWD MOVING MULTICELL CLUSTERS AND LINE SEGMENTS. THESE
STORMS MAY POSE A THREAT FOR DAMAGING WIND GUSTS AND LARGE
HAIL...AREA WILL CONTINUE TO BE MONITORED FOR A WW.
..GARNER.. 04/04/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...LWX...RAH...RNK...RLX...GSP...MRX...
JKL...LMK...
LAT...LON 35148082 36498371 37768453 38338297 37257647 35417652
35148082SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 4, 2:27 PM EDT | Severe Thunderstorm Watch | SPC | Alamance, Anson, Beaufort, Bertie, Camden, Chatham and 47 more | 6 hr |
Nearby
Mesoscale Discussions in Virginia, 2012Mesoscale Discussions in North Carolina, 2012Mesoscale Discussions in Kentucky, 2012Every mesoscale discussion in 2012
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.