Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 194

March 1, 201221 counties in North Carolina; 19 counties in Tennessee; 13 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 1, 2012, 12:20 AM EST for 21 counties in North Carolina; 19 counties in Tennessee; 13 counties in Virginia. It was in force for 85 min.

The area

The outline as issued.

The facts

Issued: Mar 1, 2012, 12:20 AM EST (05:20 UTC)
Expired: Mar 1, 2012, 1:45 AM EST
In force: 85 min
Issued by: the Storm Prediction Center

All 53 counties

Alexander County, NC, Alleghany County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Caldwell County, NC, Davie County, NC, Forsyth County, NC, Haywood County, NC, Iredell County, NC, Madison County, NC, McDowell County, NC, Mitchell County, NC, Stokes County, NC, Surry County, NC, Swain County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Anderson County, TN, Blount County, TN, Carter County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hancock County, TN, Hawkins County, TN, Jefferson County, TN, Johnson County, TN, Knox County, TN, Loudon County, TN, Roane County, TN, Sevier County, TN, Sullivan County, TN, Unicoi County, TN, Union County, TN, Washington County, TN, Carroll County, VA, City of Bristol, VA, City of Galax, VA, City of Radford, VA, Floyd County, VA, Grayson County, VA, Patrick County, VA, Pulaski County, VA, Russell County, VA, Scott County, VA, Smyth County, VA, Washington County, VA, Wythe County, VA

The radar

The Knoxville radar (KMRX), 80 km from the middle of the area, began a volume at 05:22 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

Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 5.3 hours before the alert went out and 236 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 62 J/kg
Mixed-layer CIN: -165 J/kg
Mixed-layer LCL: 686 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 271 m²/s²
0-3 km storm-relative helicity: 241 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

712 
ACUS11 KWNS 010521
SWOMCD
SPC MCD 010520
NCZ000-VAZ000-TNZ000-010645-

MESOSCALE DISCUSSION 0194
NWS STORM PREDICTION CENTER NORMAN OK
1120 PM CST WED FEB 29 2012

AREAS AFFECTED...NORTHEAST TN/WESTERN VA/FAR WESTERN NC

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 010520Z - 010645Z

AN ISOLATED TORNADO AND/OR WIND DAMAGE THREAT MAY CONTINUE ON AN
ISOLATED BASIS EARLY IN THE OVERNIGHT ACROSS FAR WESTERN
VA/NORTHEAST TN/WESTERN NC. CONVECTIVE TRENDS ARE BEING MONITORED
FOR A POSSIBLE WATCH...ALTHOUGH THE EXTENT/DURATION OF THE SEVERE
THREAT SEEMS QUESTIONABLE.

STORMS HAVE INTENSIFIED IN CLOSE PROXIMITY TO AN EASTWARD ADVANCING
COLD FRONT ON THE WINDWARD SIDE OF THE APPALACHIANS...WITH THE BRUNT
OF THIS ACTIVITY OCCURRING EARLY IN THE OVERNIGHT ACROSS NORTHEAST
TN/FAR WESTERN VA. AHEAD OF THE COLD FRONT...A RELATIVELY MOIST
LOW-LEVEL SOUTHWESTERLY INFLUX CONTINUES...WITH SURFACE TEMPERATURES
REMAINING STEADY OR EVEN INCREASING A FEW DEGREES OVER THE PAST FEW
HOURS IN THE WAKE OF EARLIER CONVECTION. GIVEN ADEQUATE INSTABILITY
AND A HIGHLY SHEARED ENVIRONMENT /MORRISTOWN WSR-88D VWP IS
INDICATIVE OF AN IMPLIED 200-350 M2 PER S2 OF 0-1 KM SRH/...A FEW
SUPERCELLS INCLUDING A BRIEF TORNADO WILL REMAIN POSSIBLE ESPECIALLY
IN THE SHORT-TERM EASTWARD TOWARD THE SPINE OF THE APPALACHIANS. THE
PERSISTENCE/EVOLUTION OF THIS CONVECTION FARTHER EAST /OF THE
APPALACHIANS SPINE/ INTO THE REMAINDER OF THE CAROLINAS/SOUTHERN VA
OVERNIGHT IS UNCERTAIN...BUT A SEVERE THREAT CANNOT BE RULED OUT
THROUGH THE EARLY MORNING HOURS.

..GUYER.. 03/01/2012

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

ATTN...WFO...RAH...RNK...RLX...GSP...MRX...OHX...

LAT...LON   35968483 37108199 37158014 35967993 35288339 35968483

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 1, 3:21 AM EST	Mesoscale Discussion	SPC	Beaufort, Bertie, Camden, Chatham, Chowan, Craven and 28 more	54 min
Feb 29, 8:33 PM EST	Mesoscale Discussion	SPC	Anderson, Campbell, Claiborne, Grainger, Hancock, Hawkins and 6 more	57 min

Nearby

Mesoscale Discussions in North Carolina, 2012 Mesoscale Discussions in Tennessee, 2012 Mesoscale Discussions in Virginia, 2012 Every 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.