Alert archive / South Carolina / Mesoscale Discussions in 2012

Mesoscale Discussion 461

April 5, 201217 counties in Georgia; 19 counties in North Carolina; 44 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 5, 2012, 3:37 PM EDT for 17 counties in Georgia; 19 counties in North Carolina; 44 counties in South Carolina. It was in force for 53 min.

The area

The outline as issued.

The facts

Issued
Apr 5, 2012, 3:37 PM EDT (19:37 UTC)
Expired
Apr 5, 2012, 4:30 PM EDT
In force
53 min
Issued by
the Storm Prediction Center
All 80 counties

Burke County, GA, Chatham County, GA, Columbia County, GA, Effingham County, GA, Elbert County, GA, Franklin County, GA, Habersham County, GA, Hart County, GA, Jenkins County, GA, Lincoln County, GA, McDuffie County, GA, Rabun County, GA, Richmond County, GA, Screven County, GA, Stephens County, GA, Towns County, GA, Wilkes County, GA, Buncombe County, NC, Clay County, NC, Cleveland County, NC, Gaston County, NC, Graham County, NC, Haywood County, NC, Henderson County, NC, Jackson County, NC, Lincoln County, NC, Macon County, NC, Madison County, NC, McDowell County, NC, Mecklenburg County, NC, Polk County, NC, Rutherford County, NC, Swain County, NC, Transylvania County, NC, Union County, NC, Yancey County, NC, Abbeville County, SC, Aiken County, SC, Allendale County, SC, Anderson County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort 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, 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, Jasper County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion 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), 38 km from the middle of the area, began a volume at 19:39 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 12:00Z, 7.6 hours before the alert went out and 194 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 12:00Z on 2012-04-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 490 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 12:00Z on 2012-04-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 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
490 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
1016 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
50 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.

145 
ACUS11 KWNS 051937
SWOMCD
SPC MCD 051937 
NCZ000-SCZ000-GAZ000-TNZ000-052030-

MESOSCALE DISCUSSION 0461
NWS STORM PREDICTION CENTER NORMAN OK
0237 PM CDT THU APR 05 2012

AREAS AFFECTED...ERN GA...WRN NC...SC

CONCERNING...SEVERE THUNDERSTORM WATCH 146...

VALID 051937Z - 052030Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 146
CONTINUES.

SURFACE ANALYSIS AT 19Z INDICATES LOW PRESSURE IS SITUATED OVER
CNTRL/NERN SC...WITH A BACKDOOR COLD FRONT EXTENDING SEWD FROM WRN
NC TOWARD THE SURFACE LOW...AND THEN OFFSHORE FROM NERN SC. AIRMASS
ALONG AND S OF THE FRONT OVER SC IS VERY UNSTABLE...WITH
TEMPERATURES IN THE 80S...DEWPOINTS IN THE LOW TO MID 60S...AND
MLCAPE VALUES LOCALLY NEAR 2000 J/KG. HOWEVER...A DRY SURFACE
AIRMASS OVER GA MAY ADVECT EWD INTO SC DURING THE NEXT FEW
HRS...WHICH WOULD TEND TO REDUCE CAPE VALUES ACROSS THE WARM SECTOR
AS THE AFTERNOON PROGRESSES. IN THE SHORT-TERM...LOCALLY STRONG
LOW-LEVEL CONVERGENCE NEAR THE SC SURFACE LOW...AS WELL AS BACKED
SURFACE WINDS/ENHANCED LOW-LEVEL SHEAR...WILL INCREASE THE
PROBABILITY FOR A FEW SUPERCELLS POSING A THREAT FOR LARGE
HAIL...LOCALLY DAMAGING WIND GUSTS...AND EVEN A TORNADO. FARTHER NW
ALONG THE FRONT INTO NRN/WRN SC AND WRN NC...FAVORABLE DEEP-LAYER
WLY SHEAR AND MLCAPE VALUES FROM 1000-1500 J/KG SUPPORT A CONTINUED
THREAT FOR SVR MULTICELL CLUSTERS AND A FEW SUPERCELLS...WITH AN
ATTENDANT THREAT FOR LARGE HAIL AND DAMAGING WIND GUSTS.

..GARNER.. 04/05/2012

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

ATTN...WFO...RAH...ILM...CHS...CAE...GSP...MRX...FFC...

LAT...LON   34818373 35338404 35518389 36048265 36048222 35568176
            35558153 35508081 34807995 34257955 34287907 33857854
            33577901 33077930 31828075 31838115 32448156 32608203
            32848230 33248226 34818373

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 5, 1:03 PM EDTMesoscale DiscussionSPCBanks, Burke, Clarke, Columbia, Effingham, Elbert and 24 more87 min
Apr 5, 1:47 PM EDTSevere Thunderstorm WatchSPCBryan, Bulloch, Burke, Candler, Chatham, Columbia and 17 more7 hr
Apr 5, 1:54 PM EDTMesoscale DiscussionSPCBartow, Catoosa, Chattooga, Cherokee, Dade, Dawson and 11 more96 min
Apr 5, 2:12 PM EDTMesoscale DiscussionSPCBaker, Calhoun, Chattahoochee, Clay, Coweta, Crawford and 30 more93 min
Apr 5, 2:58 PM EDTSevere Thunderstorm WatchSPCBaker, Ben Hill, Calhoun, Chattahoochee, Clay, Colquitt and 36 more6 hr
Apr 5, 4:49 PM EDTMesoscale DiscussionSPCAtkinson, Baker, Ben Hill, Berrien, Brooks, Calhoun and 33 more86 min
Apr 5, 6:35 PM EDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Columbia and 12 more85 min
Apr 5, 7:15 PM EDTMesoscale DiscussionSPCHeard45 min
Apr 5, 2:21 PM EDTSevere Thunderstorm WatchSPCCherokee, Clay8 hr
Apr 5, 4:06 PM EDTMesoscale DiscussionSPCCherokee, Clay54 min

Nearby

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