Alert archive / North Carolina / Mesoscale Discussions in 2012
Mesoscale Discussion 355
The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 7:34 PM EDT for 29 counties in North Carolina; 29 counties in Virginia. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Mar 24, 2012, 7:34 PM EDT (23:34 UTC)
- Expired
- Mar 24, 2012, 9:30 PM EDT
- In force
- 116 min
- Issued by
- the Storm Prediction Center
All 58 counties
Alamance County, NC, Anson County, NC, Caswell County, NC, Chatham County, NC, Cumberland County, NC, Durham County, NC, Edgecombe County, NC, Franklin County, NC, Granville County, NC, Greene County, NC, Halifax County, NC, Harnett County, NC, Hoke County, NC, Johnston County, NC, Lee County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, Northampton County, NC, Orange County, NC, Person County, NC, Richmond County, NC, Sampson County, NC, Scotland County, NC, Vance County, NC, Wake County, NC, Warren County, NC, Wayne County, NC, Wilson County, NC, Amelia County, VA, Appomattox County, VA, Brunswick County, VA, Buckingham County, VA, Campbell County, VA, Charles City County, VA, Charlotte County, VA, Chesterfield County, VA, City of Colonial Heights, VA, City of Emporia, VA, City of Hopewell, VA, City of Petersburg, VA, City of Richmond, VA, Cumberland County, VA, Dinwiddie County, VA, Goochland County, VA, Greensville County, VA, Halifax County, VA, Hanover County, VA, Henrico County, VA, King William County, VA, Lunenburg County, VA, Mecklenburg County, VA, New Kent County, VA, Nottoway County, VA, Powhatan County, VA, Prince Edward County, VA, Prince George County, VA, Sussex County, VA
The radar
The Raleigh/Durham radar (KRAX), 73 km from the middle of the area, began a volume at 23:37 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, 11.6 hours before the alert went out and 109 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.
886
ACUS11 KWNS 242334
SWOMCD
SPC MCD 242334
VAZ000-NCZ000-250130-
MESOSCALE DISCUSSION 0355
NWS STORM PREDICTION CENTER NORMAN OK
0634 PM CDT SAT MAR 24 2012
AREAS AFFECTED...PORTIONS CENTRAL/ERN NC...CENTRAL/SRN VA.
CONCERNING...TORNADO WATCH 108...109...
VALID 242334Z - 250130Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 108...109...CONTINUES.
CONTINUE WWS ALONG AND E OF PRIMARY QUASI-LINEAR CONVECTIVE
SYSTEM...QLCS...THAT WAS EVIDENT AT 2315Z ALONG ARC FROM LYH-DAN-HBI
THEN SSWWD OVER CENTRAL NC. MAIN THREAT APPEARS TO BE DAMAGING
GUSTS...THOUGH ISOLATED SVR HAIL STILL IS POSSIBLE FROM RELATIVELY
DISCRETE CELLS AND NWD/LEFT-MOVERS. TORNADO THREAT PERSISTS FROM
VARIETY OF POSSIBLE QLCS CIRCULATIONS RELATED TO EMBEDDED
SUPERCELL/BOW STRUCTURES OR LEADING-EDGE MISOVORTICES.
AT 23Z...QUASISTATIONARY FRONTAL ZONE WAS DRAWN FROM CAPE CHARLES VA
AREA WNWWD NEAR LKU AND CHO. REMNANT OUTFLOW BOUNDARY WAS ESTIMATED
FROM LAST VIS IMAGERY AND AVAILABLE SFC DATA OVER
ORANGE...BUCKINGHAM AND APPOMATTOX COUNTIES VA...INTERSECTING NRN
PORTION OF QLCS INVOF PERSISTENT AND OCCASIONALLY SUPERCELLULAR
APPOMATTOX COUNTY TSTM. THIS BOUNDARY APPEARS TO BE GETTING MORE
DIFFUSE...BUT STILL MAY SUPPLY ENHANCED LOW-LEVEL SHEAR/VORTICITY IN
SUPPORT OF SVR POTENTIAL. AIR MASS SE OF THIS BOUNDARY...S OF FRONT
AND E OF QLCS WILL CONTINUE TO SUPPORT SVR POTENTIAL FOR A FEW MORE
HOURS. SFC MESOANALYSIS SHOWS MOIST AXIS FROM PAMLICO SOUND NWWD
ACROSS SERN VA THEN ALONG OR JUST S OF QUASISTATIONARY FRONT.
SECONDARY MOIST AXIS WAS DRAWN NEAR ILM-RDU LINE...REINFORCED BY
INGOING PRECIP ASSOCIATED WITH NEWD-MOVING AND CURRENTLY NON-SVR
CONVECTION. NARROW CORRIDOR OF RELATIVELY UNSTABLE BOUNDARY-LAYER
AIR IS EVIDENT ALONG AND W OF BOTH MOIST AXES AND AHEAD OF QLCS.
MODIFIED FCST SOUNDINGS AND RUC MESOANALYSES EACH SUGGEST 500-800
J/KG MLCAPE IN CENTRAL VA...INCREASING TO NEAR 2000 J/KG OVER
CENTRAL NC. THESE VALUES WILL DIMINISH WITH TIME AS BOUNDARY LAYER
COOLS. HOWEVER...WITH 35-50 KT EFFECTIVE SHEAR MAGNITUDES ESTIMATED
JUST AHEAD OF QLCS...POTENTIAL WILL PERSIST FOR ORGANIZED SVR
THROUGH AT LEAST 03Z.
..EDWARDS.. 03/24/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...
LAT...LON 34838023 36257939 37037916 37327917 38017785 37647691
35957731 34817821 34838023SPC 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, 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, 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, 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.