Alert archive / North Carolina / Mesoscale Discussions in 2011

Mesoscale Discussion 261

March 23, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Mar 23, 2011, 4:48 PM EDT for 4 states. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Mar 23, 2011, 4:48 PM EDT (20:48 UTC)
Expired
Mar 23, 2011, 5:45 PM EDT
In force
57 min
Issued by
the Storm Prediction Center
All 98 counties

Alamance County, NC, Alexander County, NC, Alleghany County, NC, Anson County, NC, Ashe County, NC, Avery County, NC, Buncombe County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Caswell County, NC, Catawba County, NC, Chatham County, NC, Clay County, NC, Cleveland County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Graham County, NC, Granville County, NC, Guilford County, NC, Harnett County, NC, Haywood County, NC, Henderson County, NC, Iredell County, NC, Jackson County, NC, Lee County, NC, Lincoln County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mecklenburg County, NC, Mitchell County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Orange County, NC, Person County, NC, Polk County, NC, Randolph County, NC, Rockingham County, NC, Rowan County, NC, Rutherford County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Swain County, NC, Transylvania County, NC, Union County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Watauga County, NC, Wilkes County, NC, Yadkin County, NC, Yancey County, NC, Cherokee County, SC, Chester County, SC, Greenville County, SC, Lancaster County, SC, Pickens County, SC, Spartanburg County, SC, York County, SC, Carter County, TN, Cocke County, TN, Johnson County, TN, Sevier County, TN, Unicoi County, TN, Amelia County, VA, Amherst County, VA, Appomattox County, VA, Bedford County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Carroll County, VA, Charlotte County, VA, City of Danville, VA, City of Galax, VA, City of Lynchburg, VA, City of Martinsville, VA, City of Roanoke, VA, Cumberland County, VA, Dinwiddie County, VA, Floyd County, VA, Franklin County, VA, Grayson County, VA, Halifax County, VA, Henry County, VA, Lunenburg County, VA, Mecklenburg County, VA, Nottoway County, VA, Patrick County, VA, Pittsylvania County, VA, Prince Edward County, VA

The radar

The Roanoke radar (KFCX), 139 km from the middle of the area, began a volume at 20:51 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, 8.8 hours before the alert went out and 86 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-pSkew-T log-p diagram, Greensboro/Hi Pt, NC at 12:00Z on 2011-03-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Greensboro/Hi Pt, NC at 12:00Z on 2011-03-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 square meters per square second.1939587897Sfc1 km3 km6 km9 kmRMLM
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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1642 m above ground
0-6 km bulk shear
57 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
119 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.

015 
ACUS11 KWNS 232048
SWOMCD
SPC MCD 232048 
VAZ000-NCZ000-SCZ000-TNZ000-GAZ000-232145-

MESOSCALE DISCUSSION 0261
NWS STORM PREDICTION CENTER NORMAN OK
0348 PM CDT WED MAR 23 2011

AREAS AFFECTED...ERN TN...NRN SC...NC...VA

CONCERNING...TORNADO WATCH 56...

VALID 232048Z - 232145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 56 CONTINUES.

A SEVERE THREAT SHOULD DEVELOP EWD ACROSS WRN-CNTRL NC AND SRN VA
OVER THE NEXT FEW HOURS. LARGE HAIL AND WIND DAMAGE WILL BE POSSIBLE
WITH THE STRONGER CELLS. A WW IS BEING CONSIDERED FOR THE AREA AND
MAY BE ISSUED LATE THIS AFTERNOON.

A CLUSTER OF THUNDERSTORMS CURRENTLY EXTENDING FROM FAR WRN VA SWWD
INTO ERN TN WILL CONTINUE TO MOVE EWD ACROSS THE SRN APPALACHIAN
MTNS THIS AFTERNOON. ALTHOUGH THE ATMOSPHERE IN THE SRN APPALACHIANS
IS ONLY WEAKLY UNSTABLE...DEEP LAYER SHEAR SHOULD CONTINUE TO
STRENGTHEN AS AN 80 TO 95 KT MID-LEVEL JET APPROACHES FROM THE WEST.
THIS COMBINED WITH COLD TEMPS ALOFT WILL PROVIDE SUPPORT FOR A HAIL
THREAT WITH THE MORE INTENSE CORES. AS THE MID-LEVEL JET MOVES INTO
THE REGION FROM THE WEST...BOUNDARY LAYER FLOW IS ALSO FORECAST TO
INCREASE AS A 40 TO 50 KT LOW-LEVEL JET DEVELOPS. THIS MAY BE ENOUGH
FOR AN ISOLATED WIND DAMAGE THREAT ESPECIALLY IF THE STORMS CAN
ORGANIZE INTO A LINE.

..BROYLES.. 03/23/2011

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

ATTN...WFO...AKQ...LWX...RAH...RNK...CAE...GSP...MRX...

LAT...LON   34638080 34788266 35118405 35568406 35998329 37038038
            37787913 37317742 36117782 35457852 34638080

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 23, 3:38 PM EDTMesoscale DiscussionSPCAlleghany, Ashe, Avery, Caldwell, Mitchell, Watauga and 2 more37 min
Mar 23, 3:45 PM EDTTornado WatchSPCAlexander, Alleghany, Ashe, Avery, Buncombe, Burke and 21 more6 hr
Mar 23, 6:04 PM EDTSevere Thunderstorm WatchSPCAlamance, Bertie, Chatham, Davidson, Durham, Edgecombe and 16 more7 hr
Mar 23, 7:10 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Anson, Ashe, Avery and 53 more65 min
Mar 23, 2:40 PM EDTMesoscale DiscussionSPCAnderson, Bedford, Benton, Bledsoe, Campbell, Cannon and 62 more65 min
Mar 23, 5:06 PM EDTTornado WatchSPCBedford, Benton, Cannon, Carroll, Cheatham, Chester and 50 more6 hr
Mar 23, 12:02 PM EDTMesoscale DiscussionSPCBuchanan, Dickenson88 min
Mar 23, 1:13 PM EDTTornado WatchSPCBuchanan, Dickenson7 hr
Mar 23, 3:54 PM EDTMesoscale DiscussionSPCAlbemarle, Alleghany, Amherst, Appomattox, Augusta, Bath and 51 more96 min
Mar 23, 4:13 PM EDTSevere Thunderstorm WatchSPCAlbemarle, Arlington, Augusta, Clarke, Culpeper, Fairfax and 27 more5 hr

Nearby

Mesoscale Discussions in North Carolina, 2011Mesoscale Discussions in Virginia, 2011Mesoscale Discussions in South 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.