Alert archive / Virginia / Mesoscale Discussions in 2012

Mesoscale Discussion 348

March 24, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Mar 24, 2012, 4:16 PM EDT for 5 states. It was in force for 59 min.

The area

The outline as issued.

The facts

Issued
Mar 24, 2012, 4:16 PM EDT (20:16 UTC)
Expired
Mar 24, 2012, 5:15 PM EDT
In force
59 min
Issued by
the Storm Prediction Center
All 47 counties

Richmond County, GA, Cabarrus County, NC, Davidson County, NC, Davie County, NC, Forsyth County, NC, Iredell County, NC, Mecklenburg County, NC, Rowan County, NC, Stanly County, NC, Stokes County, NC, Surry County, NC, Union County, NC, Yadkin County, NC, Aiken County, SC, Chester County, SC, Edgefield County, SC, Fairfield County, SC, Kershaw County, SC, Lancaster County, SC, Lexington County, SC, Newberry County, SC, Richland County, SC, Saluda County, SC, York County, SC, Alleghany County, VA, Bath County, VA, Botetourt County, VA, City of Covington, VA, City of Roanoke, VA, City of Salem, VA, Craig County, VA, Floyd County, VA, Franklin County, VA, Henry County, VA, Montgomery County, VA, Patrick County, VA, Roanoke County, VA, Braxton County, WV, Gilmer County, WV, Greenbrier County, WV, Lewis County, WV, Monroe County, WV, Nicholas County, WV, Pocahontas County, WV, Randolph County, WV, Upshur County, WV, Webster County, WV

The radar

The Roanoke radar (KFCX), 128 km from the middle of the area, began a volume at 20:17 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, 8.3 hours before the alert went out and 94 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 2012-03-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 226 joules per kilogram.LCLLFCEL10008507005003002001001 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 2012-03-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 167 square meters per square second.19395878Sfc1 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
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

Open this sounding in Storm Lab

The text

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

650 
ACUS11 KWNS 242017
SWOMCD
SPC MCD 242016
VAZ000-WVZ000-NCZ000-SCZ000-GAZ000-242115-

MESOSCALE DISCUSSION 0348
NWS STORM PREDICTION CENTER NORMAN OK
0316 PM CDT SAT MAR 24 2012

AREAS AFFECTED...SRN/ERN WV...WRN VA/NC/SC

CONCERNING...SEVERE THUNDERSTORM WATCH 105...106...107...

VALID 242016Z - 242115Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
105...106...107...CONTINUES.

ARCING BAND OF DISCRETE AND CLUSTER TSTMS FROM SRN WV TO WRN SC WILL
LIKELY DEVELOP EWD TOWARDS THE VA/CAROLINA PIEDMONT. PORTIONS OF WW
105 WERE RECENTLY UPGRADED TO TORNADO WATCH 108 WHERE THE RELATIVELY
GREATEST TORNADO RISK SHOULD LIE WITHIN THIS BAND.

WITH SWRN EXTENT IN THE WRN CAROLINAS...MORE UNIDIRECTIONAL
LOW-LEVEL SWLYS SAMPLED BY THE CAE/GSP VWP DATA AND LARGER SURFACE
TEMPERATURE/DEW POINT SPREADS SHOULD MITIGATE TORNADIC POTENTIAL
HERE. HOWEVER...IN THE MIDST OF 40-50 KT EFFECTIVE SHEAR...SPLITTING
SUPERCELLS WILL REMAIN CAPABLE OF PRODUCING SEVERE HAIL/WIND. SEVERE
THREAT APPEARS TO BE DIMINISHING IN AREAS WEST OF THE ARCING BAND OF
STRONG TO SEVERE TSTMS AS SURFACE DEW POINTS HAVE MIXED INTO THE
40S.

WITH NRN EXTENT IN SRN/ERN WV AND PARTS OF WRN VA...CONVECTION HAS
LARGELY STRUGGLED TO MAINTAIN ROBUST UPDRAFTS N OF AN OUTFLOW
BOUNDARY ACROSS SWRN TO CNTRL VA. ALTHOUGH DEEP-LAYER SHEAR IS
STRONG...VEER-BACK WIND PROFILES ALONG WITH LESSER INSTABILITY
RELATIVE TO AREAS FARTHER S SUGGEST OCCURRENCES OF SEVERE HAIL/WIND
SHOULD BE MORE MARGINAL/SPORADIC.

..GRAMS.. 03/24/2012

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

ATTN...WFO...LWX...RAH...RNK...RLX...CAE...GSP...

LAT...LON   33728235 34468161 35378103 37148049 38578096 38858104
            39138083 39198024 39007977 37907948 35958013 34858019
            34208065 33598125 33188165 33318207 33728235

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 24, 10:16 AM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Berrien, Brantley, Bryan and 25 more59 min
Mar 24, 10:45 AM EDTSevere Thunderstorm WatchSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 23 more8 hr
Mar 24, 12:29 PM EDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Brantley, Bryan, Bulloch and 19 more61 min
Mar 24, 4:19 PM EDTMesoscale DiscussionSPCBrantley, Camden, Charlton, Clinch, Echols, Glynn and 6 more86 min
Mar 24, 5:52 PM EDTMesoscale DiscussionSPCChattooga, Dade, Walker53 min
Mar 24, 6:25 PM EDTMesoscale DiscussionSPCBrantley, Bryan, Camden, Charlton, Chatham, Clinch and 8 more65 min
Mar 24, 12:03 PM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Anson, Cabarrus, Caswell and 20 more117 min
Mar 24, 12:46 PM EDTSevere Thunderstorm WatchSPCAlamance, Alexander, Alleghany, Anson, Ashe, Avery and 33 more7 hr
Mar 24, 2:31 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Ashe, Avery, Burke, Caldwell and 4 more59 min
Mar 24, 2:54 PM EDTMesoscale DiscussionSPCCaswell, Forsyth, Guilford, Rockingham, Stokes, Surry and 1 more66 min
Mar 24, 3:38 PM EDTTornado WatchSPCAlamance, Anson, Caswell, Chatham, Cumberland, Davidson and 30 more7 hr
Mar 24, 6:03 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Brunswick, Camden, Carteret and 24 more2 hr
Mar 24, 6:43 PM EDTTornado WatchSPCCaswell, Rockingham4 hr
Mar 24, 6:58 PM EDTMesoscale DiscussionSPCAlexander, Alleghany, Burke, Cabarrus, Caldwell, Catawba and 9 more92 min
Mar 24, 7:34 PM EDTMesoscale DiscussionSPCAlamance, Anson, Caswell, Chatham, Cumberland, Durham and 23 more116 min
Mar 24, 1:53 PM EDTSevere Thunderstorm WatchSPCAiken, Allendale, Bamberg, Barnwell, Beaufort, Berkeley and 32 more7 hr
Mar 24, 7:21 PM EDTMesoscale DiscussionSPCAiken, Bamberg, Barnwell, Berkeley, Calhoun, Charleston and 17 more84 min
Mar 24, 3:02 PM EDTSevere Thunderstorm WatchSPCAlbemarle, Alleghany, Amherst, Appomattox, Augusta, Bath and 13 more5 hr

Nearby

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