Alert archive / North Carolina / Mesoscale Discussions in 2012
Mesoscale Discussion 344
The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 12:03 PM EDT for 4 states. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Mar 24, 2012, 12:03 PM EDT (16:03 UTC)
- Expired
- Mar 24, 2012, 2:00 PM EDT
- In force
- 117 min
- Issued by
- the Storm Prediction Center
All 61 counties
Alamance County, NC, Alexander County, NC, Alleghany County, NC, Anson County, NC, Cabarrus County, NC, Caswell County, NC, Catawba County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Gaston County, NC, Guilford County, NC, Iredell County, NC, Lincoln County, NC, Mecklenburg County, NC, Montgomery County, NC, Randolph County, NC, Richmond County, NC, Rockingham County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Wilkes County, NC, Yadkin County, NC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Edgefield County, SC, Fairfield County, SC, Greenwood County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lexington County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, Union County, SC, York County, SC, Bland County, VA, Carroll County, VA, City of Danville, VA, City of Galax, VA, City of Martinsville, VA, City of Radford, VA, City of Roanoke, VA, City of Salem, VA, Floyd County, VA, Franklin County, VA, Giles County, VA, Grayson County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Pulaski County, VA, Roanoke County, VA, Smyth County, VA, Wythe County, VA, Mercer County, WV
The radar
The Greer radar (KGSP), 130 km from the middle of the area, began a volume at 16:05 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, 4.1 hours before the alert went out and 119 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
- 226 J/kg
- Mixed-layer CIN
- -8 J/kg
- Mixed-layer LCL
- 526 m above ground
- 0-6 km bulk shear
- 24 kt
- 0-1 km storm-relative helicity
- 167 m²/s²
- 0-3 km storm-relative helicity
- 153 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 0.5
The text
As transmitted, in the capitals the NWS used until 2016.
245
ACUS11 KWNS 241603
SWOMCD
SPC MCD 241603
NCZ000-VAZ000-SCZ000-WVZ000-241800-
MESOSCALE DISCUSSION 0344
NWS STORM PREDICTION CENTER NORMAN OK
1103 AM CDT SAT MAR 24 2012
AREAS AFFECTED...LEE OF THE SRN APPALACHIANS TO THE VA/NC/SC
PIEDMONT
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 241603Z - 241800Z
SEVERE POTENTIAL WILL INCREASE THIS AFTERNOON WITH SEVERAL
SUPERCELLS EXPECTED WITHIN AN ARCING BAND OF SEMI-DISCRETE TSTMS.
PRIMARY INITIAL THREAT WILL BE LARGE HAIL...WITH EVENTUAL THREATS
FOR DAMAGING WINDS AND A FEW TORNADOES. THE PROBABILITY OF A WW
ISSUANCE IS 95 PERCENT.
15Z SURFACE ANALYSIS A SERIES OF WEAK CYCLONES ALONG A FRACTURED
COLD FRONT ACROSS WRN VA INTO THE WRN CAROLINAS SWWD INTO CNTRL GA.
AN ARCING BAND OF TCU/SMALL CBS RUNNING ALONG THIS AXIS SHOULD SERVE
AS THE FOCUS FOR ROBUST TSTM DEVELOPMENT BY MID-AFTERNOON GIVEN
FURTHER HEATING AND AS LARGE-SCALE ASCENT INCREASES DOWNSTREAM OF
UPPER-LEVEL IMPULSE SHIFTING SEWD ACROSS THE TN VALLEY.
CONVECTION-ALLOWING AND OPERATIONAL MODEL GUIDANCE ARE CONSISTENT
WITH ADVERTISING THIS SCENARIO.
EVIDENCE OF BACKING MID-LEVEL WINDS HAVE BEEN NOTED IN 12Z GSO/RNK
RAOBS ALONG WITH CURRENT FCX/RAH VWP DATA. THIS WEAKNESS IN THE
HODOGRAPH MAY LIMIT SUPERCELL STRUCTURES INITIALLY. HOWEVER...WITH
TIME MODEL GUIDANCE INDICATE SWLY WIND PROFILES WILL BECOME MORE
UNIDIRECTIONAL AND RESULT IN STRONG EFFECTIVE SHEAR AROUND 40 KT.
WITH MLCAPE EXPECTED TO INCREASE TO BETWEEN 1000-2000 J/KG...THREAT
FOR SUPERCELLS PRODUCING LARGE HAIL WILL EXIST. SOMEWHAT STRONGER
LOW-LEVEL SWLYS AMIDST MORE BACKED NEAR-SURFACE FLOW IS EXPECTED TO
BE MAINTAINED FARTHER E ACROSS THE PIEDMONT AND SHOULD AID IN THE
POTENTIAL FOR A FEW TORNADOES LATER THIS AFTERNOON.
..GRAMS.. 03/24/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...RAH...ILM...RNK...RLX...CAE...GSP...
LAT...LON 35278152 36158132 36888165 37368140 37598084 37548044
37077948 36207925 34607989 33868072 33668137 33688190
34068243 34428217 35278152SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| 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, 2:54 PM EDT | Mesoscale Discussion | SPC | Caswell, Forsyth, Guilford, Rockingham, Stokes, Surry and 1 more | 66 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, 12:29 PM EDT | Mesoscale Discussion | SPC | Beaufort, Colleton, Hampton, Jasper | 61 min |
| Mar 24, 1:53 PM EDT | Severe Thunderstorm Watch | SPC | Aiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 32 more | 7 hr |
| Mar 24, 7:21 PM EDT | Mesoscale Discussion | SPC | Aiken, Bamberg, Barnwell, Berkeley, Calhoun, Charleston and 17 more | 84 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 North Carolina, 2012Mesoscale Discussions in Virginia, 2012Mesoscale Discussions in South Carolina, 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.