Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 347

March 24, 20127 counties in North Carolina; 11 counties in Virginia

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 2:54 PM EDT for 7 counties in North Carolina; 11 counties in Virginia. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued: Mar 24, 2012, 2:54 PM EDT (18:54 UTC)
Expired: Mar 24, 2012, 4:00 PM EDT
In force: 66 min
Issued by: the Storm Prediction Center

Counties Caswell County, NC, Forsyth County, NC, Guilford County, NC, Rockingham County, NC, Stokes County, NC, Surry County, NC, Yadkin County, NC, Appomattox County, VA, Bedford County, VA, Campbell County, VA, City of Danville, VA, City of Martinsville, VA, Floyd County, VA, Franklin County, VA, Halifax County, VA, Henry County, VA, Patrick County, VA, Pittsylvania County, VA

The radar

The Roanoke radar (KFCX), 53 km from the middle of the area, began a volume at 18:56 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

Roanoke, VA (KRNK), launched 12:00Z, 6.9 hours before the alert went out and 58 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: 250 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 519 m above ground
0-6 km bulk shear: 45 kt
0-1 km storm-relative helicity: 45 m²/s²
0-3 km storm-relative helicity: -13 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

237 
ACUS11 KWNS 241855
SWOMCD
SPC MCD 241854
VAZ000-NCZ000-242000-

MESOSCALE DISCUSSION 0347
NWS STORM PREDICTION CENTER NORMAN OK
0154 PM CDT SAT MAR 24 2012

AREAS AFFECTED...SWRN VA...NWRN NC

CONCERNING...SEVERE THUNDERSTORM WATCH 105...

VALID 241854Z - 242000Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 105
CONTINUES.

LOCALIZED TORNADO THREAT MAY DEVELOP ALONG THE JUXTAPOSITION OF A
REMNANT OUTFLOW BOUNDARY ACROSS SRN VA AND DIFFERENTIAL HEATING ZONE
ACROSS NRN NC. LOW-LEVEL SRH IS LIKELY ENHANCED WITHIN THIS
CORRIDOR...WHICH HAS SUPPORTED DEVELOPMENT OF A DISCRETE SUPERCELL
ALONG THE CARROLL COUNTY VA AND SURRY COUNTY NC BORDER. LARGE HAIL
/POTENTIALLY SIGNIFICANT/ AND ISOLATED DAMAGING WINDS SHOULD REMAIN
THE PRIMARY THREAT. BUT PORTIONS OF WW 105 ARE BEING MONITORED FOR A
POSSIBLE UPGRADE TO A TORNADO WATCH.

..GRAMS.. 03/24/2012

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

ATTN...WFO...AKQ...RAH...RNK...

LAT...LON   36818069 37028033 37237986 37397922 37477884 37287865
            36797881 36407912 36087966 36028014 36098057 36248079
            36818069

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Mar 24, 12:03 PM EDT	Mesoscale Discussion	SPC	Alamance, Alexander, Alleghany, Anson, Cabarrus, Caswell and 20 more	117 min
Mar 24, 12:46 PM EDT	Severe Thunderstorm Watch	SPC	Alamance, Alexander, Alleghany, Anson, Ashe, Avery and 33 more	7 hr
Mar 24, 2:31 PM EDT	Mesoscale Discussion	SPC	Alexander, Alleghany, Ashe, Avery, Burke, Caldwell and 4 more	59 min
Mar 24, 3:38 PM EDT	Tornado Watch	SPC	Alamance, Anson, Caswell, Chatham, Cumberland, Davidson and 30 more	7 hr
Mar 24, 4:16 PM EDT	Mesoscale Discussion	SPC	Cabarrus, Davidson, Davie, Forsyth, Iredell, Mecklenburg and 6 more	59 min
Mar 24, 6:03 PM EDT	Mesoscale Discussion	SPC	Beaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 24 more	2 hr
Mar 24, 6:43 PM EDT	Tornado Watch	SPC	Caswell, Rockingham	4 hr
Mar 24, 6:58 PM EDT	Mesoscale Discussion	SPC	Alexander, Alleghany, Burke, Cabarrus, Caldwell, Catawba and 9 more	92 min
Mar 24, 7:34 PM EDT	Mesoscale Discussion	SPC	Alamance, Anson, Caswell, Chatham, Cumberland, Durham and 23 more	116 min
Mar 24, 3:02 PM EDT	Severe Thunderstorm Watch	SPC	Albemarle, Alleghany, Amherst, Appomattox, Augusta, Bath and 13 more	5 hr

Nearby

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