Alert archive / North Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 822

May 15, 201216 counties in Georgia; 53 counties in North Carolina; 44 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at May 15, 2012, 8:42 PM EDT for 16 counties in Georgia; 53 counties in North Carolina; 44 counties in South Carolina. It was in force for 63 min.

The area

The outline as issued.

The facts

Issued
May 15, 2012, 8:42 PM EDT (00:42 UTC)
Expired
May 15, 2012, 9:45 PM EDT
In force
63 min
Issued by
the Storm Prediction Center
All 113 counties

Bulloch County, GA, Burke County, GA, Candler County, GA, Columbia County, GA, Effingham County, GA, Elbert County, GA, Evans County, GA, Franklin County, GA, Hart County, GA, Jenkins County, GA, Lincoln County, GA, McDuffie County, GA, Richmond County, GA, Screven County, GA, Stephens County, GA, Wilkes County, GA, Alamance County, NC, Alexander County, NC, Anson County, NC, Bladen County, NC, Brunswick County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Chatham County, NC, Cleveland County, NC, Columbus County, NC, Cumberland County, NC, Davidson County, NC, Davie County, NC, Durham County, NC, Edgecombe County, NC, Forsyth County, NC, Franklin County, NC, Gaston County, NC, Granville County, NC, Guilford County, NC, Halifax County, NC, Harnett County, NC, Henderson County, NC, Hoke County, NC, Iredell County, NC, Johnston County, NC, Lee County, NC, Lincoln County, NC, McDowell County, NC, Mecklenburg County, NC, Montgomery County, NC, Moore County, NC, Nash County, NC, New Hanover County, NC, Orange County, NC, Pender County, NC, Polk County, NC, Randolph County, NC, Richmond County, NC, Robeson County, NC, Rowan County, NC, Rutherford County, NC, Sampson County, NC, Scotland County, NC, Stanly County, NC, Transylvania County, NC, Union County, NC, Wake County, NC, Wayne County, NC, Wilson County, NC, Yadkin County, NC, Abbeville County, SC, Aiken County, SC, Allendale County, SC, Anderson County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Charleston County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Georgetown County, SC, Greenville County, SC, Greenwood County, SC, Hampton County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Orangeburg County, SC, Pickens County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC, York County, SC

The radar

The Columbia radar (KCAE), 127 km from the middle of the area, began a volume at 00:45 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 nearest sounding before it

Charleston AFB, SC (KCHS), launched 00:00Z, 0.7 hours before the alert went out and 164 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, Charleston AFB, SC at 00:00Z on 2012-05-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 867 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, Charleston AFB, SC at 00:00Z on 2012-05-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 63 square meters per square second.193958Sfc1 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
867 J/kg
Mixed-layer CIN
-65 J/kg
Mixed-layer LCL
1124 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
63 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.4

Open this sounding in Storm Lab

The text

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

312 
ACUS11 KWNS 160043
SWOMCD
SPC MCD 160042
NCZ000-SCZ000-GAZ000-160145-

MESOSCALE DISCUSSION 0822
NWS STORM PREDICTION CENTER NORMAN OK
0742 PM CDT TUE MAY 15 2012

AREAS AFFECTED...SC...PORTIONS OF NC...ERN GA

CONCERNING...SEVERE THUNDERSTORM WATCH 278...279...

VALID 160042Z - 160145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
278...279...CONTINUES.

SUMMARY...STORMS WILL CONTINUE TO DECREASE IN NUMBER AND INTENSITY
THROUGH THE EVENING HOURS. REMAINING VALID PORTIONS OF SEVERE
THUNDERSTORM WATCHES 278 AND 279 WILL BE ALLOWED TO EXPIRE BY THE
SCHEDULED EXPIRATION TIMES OF 01Z AND 02Z...RESPECTIVELY.

DISCUSSION...LOW-LEVEL STABILIZATION OWING TO CONVECTIVE OVERTURNING
AND THE DEVELOPMENT OF THE NOCTURNAL BOUNDARY LAYER WILL RESULT IN
THE WEAKENING OF ONGOING CONVECTION DURING THE NEXT COUPLE OF HOURS.
WHILE A FEW STRONG STORMS MAY REMAIN POSSIBLE IN THE NEAR-TERM AS
BOUNDARY COLLISIONS CONTINUE AMIDST A CONDITIONALLY UNSTABLE AIR
MASS...INCREASING CINH WILL YIELD A DIMINISHING SVR THREAT.
ACCORDINGLY...REMAINING VALID PORTIONS OF WW 278 AND WW 279 WILL BE
ALLOWED TO EXPIRE BY THE SCHEDULED EXPIRATION TIMES OF 01Z AND
02Z...RESPECTIVELY.

..COHEN.. 05/16/2012

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

ATTN...WFO...AKQ...MHX...RAH...ILM...RNK...CHS...CAE...GSP...
FFC...

LAT...LON   33057901 32857970 32528091 32078160 32168200 32548225
            33438248 33798282 34518347 35168309 35938193 36278038
            36357935 36367820 36347761 36207741 35897736 35297795
            34897817 34677784 34347755 33827757 33407837 33057901

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 16, 12:24 PM EDTMesoscale DiscussionSPCBeaufort, Bladen, Brunswick, Camden, Carteret, Columbus and 14 more66 min

Nearby

Mesoscale Discussions in North Carolina, 2012Mesoscale Discussions in South Carolina, 2012Mesoscale Discussions in Georgia, 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.