Alert archive / Georgia / Mesoscale Discussions in 2012

Mesoscale Discussion 1340

July 1, 201231 counties in Georgia; 9 counties in North Carolina; 31 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 4:15 PM EDT for 31 counties in Georgia; 9 counties in North Carolina; 31 counties in South Carolina. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Jul 1, 2012, 4:15 PM EDT (20:15 UTC)
Expired
Jul 1, 2012, 5:45 PM EDT
In force
90 min
Issued by
the Storm Prediction Center
All 71 counties

Baldwin County, GA, Bleckley County, GA, Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Columbia County, GA, Dodge County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glascock County, GA, Hancock County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Laurens County, GA, Liberty County, GA, McDuffie County, GA, Montgomery County, GA, Pulaski County, GA, Richmond County, GA, Screven County, GA, Tattnall County, GA, Toombs County, GA, Treutlen County, GA, Twiggs County, GA, Warren County, GA, Washington County, GA, Wheeler County, GA, Wilkinson County, GA, Bladen County, NC, Brunswick County, NC, Columbus County, NC, Duplin County, NC, New Hanover County, NC, Pender County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Calhoun County, SC, Charleston 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, Hampton County, SC, Horry County, SC, Jasper County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 76 km from the middle of the area, began a volume at 20:16 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, 8.3 hours before the alert went out and 112 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 2012-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 5275 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 2012-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 0 square meters per square second.1939Sfc1 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
5275 J/kg
Mixed-layer CIN
-133 J/kg
Mixed-layer LCL
1026 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
0 m²/s²
0-3 km storm-relative helicity
-14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.8

Open this sounding in Storm Lab

The text

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

510 
ACUS11 KWNS 012016
SWOMCD
SPC MCD 012015
NCZ000-SCZ000-GAZ000-012145-

MESOSCALE DISCUSSION 1340
NWS STORM PREDICTION CENTER NORMAN OK
0315 PM CDT SUN JUL 01 2012

AREAS AFFECTED...SERN NC...SC...CNTRL GA

CONCERNING...SEVERE THUNDERSTORM WATCH 445...

VALID 012015Z - 012145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 445
CONTINUES.

SUMMARY...LARGE HAIL/ISOLATED DAMAGING WIND PERSISTS...WITH
POTENTIAL FOR SEVERE WIND GUSTS INCREASING IN SERN NC AND CNTRL/ERN
SC DURING THE NEXT FEW HOURS.

DISCUSSION...MOST INTENSE MULTICELL CLUSTERS HAVE REMAINED INVOF THE
BORDER OF WW/S 442/445 IN SRN NC TO N-CNTRL SC AND LARGE HAIL UP TO
2 INCHES HAS BEEN REPORTED WITH THIS ACTIVITY. MERGING OF CELLS
APPEARS TO BE LEADING TO UPSCALE GROWTH SIMILAR TO THE EVOLUTION OF
AN ACCELERATING LINE IN N-CNTRL/NERN NC. WITH 8.5-9.5 C/KM 700-500
MB LAPSE RATES SAMPLED IN 18Z CHS/MHX RAOBS...THE EXTREME
INSTABILITY SHOULD LEND ITSELF TO SUBSTANTIAL COLD POOL FORMATION
AND ACCELERATE S/SEWD PROPAGATION OF ONGOING ACTIVITY. THIS
EVOLUTION MAY YIELD BOWING SEGMENTS AND INCREASING
COVERAGE/INTENSITY OF SEVERE WIND GUSTS PRIMARILY TOWARD THE NC/SC
COASTAL PLAIN.

WITH SWRN EXTENT...DEEP-LAYER FLOW WEAKENS SUBSTANTIALLY TO THE
MID-LEVEL ANTICYCLONE CENTERED OVER CNTRL GA /PER AREA VWP DATA/.
THIS SUGGESTS COLD POOL EVOLUTION INTO GA WILL BE MORE DISORGANIZED
AND DEPENDENT ON STORM-SCALE PROCESSES TO YIELD MORE THAN SPORADIC
MICROBURSTS.

..GRAMS.. 07/01/2012

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

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

LAT...LON   35007898 35117837 34897775 34697757 34277766 32977946
            31768146 32238350 32868371 33368308 33868224 34408116
            35007898

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 1:39 PM EDTMesoscale DiscussionSPCBurke, Columbia, Richmond96 min
Jul 1, 2:01 PM EDTSevere Thunderstorm WatchSPCBryan, Bulloch, Burke, Candler, Chatham, Columbia and 11 more9 hr
Jul 1, 2:08 PM EDTMesoscale DiscussionSPCBaldwin, Barrow, Bartow, Bibb, Butts, Carroll and 62 more3 hr
Jul 1, 7:39 PM EDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Columbia and 13 more96 min
Jul 1, 9:27 AM EDTMesoscale DiscussionSPCAlleghany, Ashe, Forsyth, Rockingham, Stokes, Surry and 3 more63 min
Jul 1, 9:44 AM EDTSevere Thunderstorm WatchSPCAlleghany, Ashe, Caswell, Rockingham, Stokes, Surry and 3 more5 hr
Jul 1, 11:38 AM EDTMesoscale DiscussionSPCAlamance, Alexander, Alleghany, Ashe, Avery, Caldwell and 12 more97 min
Jul 1, 12:56 PM EDTSevere Thunderstorm WatchSPCAlamance, Anson, Beaufort, Bertie, Camden, Carteret and 51 more7 hr
Jul 1, 2:53 PM EDTMesoscale DiscussionSPCBeaufort, Bertie, Bladen, Camden, Carteret, Chowan and 37 more97 min
Jul 1, 7:04 PM EDTMesoscale DiscussionSPCAlamance, Beaufort, Bertie, Camden, Carteret, Caswell and 40 more56 min

Nearby

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