Alert archive / South Carolina / Mesoscale Discussions in 2004

Mesoscale Discussion 340

April 12, 200413 counties in Georgia; Brunswick County, Columbus County, New Hanover County, North Carolina; 25 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2004, 1:52 PM EDT for 13 counties in Georgia; Brunswick County, Columbus County, New Hanover County, North Carolina; 25 counties in South Carolina. It was in force for 113 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2004, 1:52 PM EDT (17:52 UTC)
Expired
Apr 12, 2004, 3:45 PM EDT
In force
113 min
Issued by
the Storm Prediction Center
All 41 counties

Bryan County, GA, Bulloch County, GA, Burke County, GA, Candler County, GA, Chatham County, GA, Effingham County, GA, Evans County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Richmond County, GA, Screven County, GA, Brunswick County, NC, Columbus County, NC, New Hanover 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, Clarendon County, SC, Colleton County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Orangeburg County, SC, Richland County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 96 km from the middle of the area, began a volume at 17:53 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

Charleston AFB, SC (KCHS), launched 12:00Z, 5.9 hours before the alert went out and 53 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 2004-04-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2004-04-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 142 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
753 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
142 m²/s²
0-3 km storm-relative helicity
265 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.

243 
ACUS11 KWNS 121753
SWOMCD
SPC MCD 121752 
NCZ000-SCZ000-GAZ000-121945-

MESOSCALE DISCUSSION 0340
NWS STORM PREDICTION CENTER NORMAN OK
1252 PM CDT MON APR 12 2004

AREAS AFFECTED...ERN GA / SERN SC / FAR SERN NC...

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 121752Z - 121945Z

THUNDERSTORM DEVELOPMENT POSSIBLE IN THE NEXT 1 TO 2 HOURS ACROSS
ERN GA / ERN SC.  WE ARE MONITORING THIS REGION FOR POSSIBLE WW
ISSUANCE.

LATEST SURFACE DATA AND OBJECTIVE ANALYSES INDICATE DESTABILIZING
AIRMASS SOUTH OF WEDGE FRONT ACROSS THIS REGION...WITH WEAK LOW
POSSIBLY DEVELOPING ALONG FRONT INVOF AGS.  EXTENDING SWD FROM THIS
WEAK LOW...A WIND SHIFT / CONVERGENCE AXIS IS INDICATED...WITH UPPER
60S TO LOW 70S DEWPOINTS AHEAD OF AND UPPER 50S TO LOW 60S DEWPOINTS
BEHIND THIS AXIS.  WITH 1500 TO 2000 J/KG SURFACE-BASED CAPE NOW
INDICATED ACROSS THIS REGION...POTENTIAL FOR STORM DEVELOPMENT
APPEARS TO EXIST OVER THE NEXT 1 TO 2 HOURS WITHIN LOW-LEVEL
CONVERGENCE ZONES ALONG BOTH ERN GA WIND SHIFT AND WEDGE FRONT.

LATEST VWP DATA ACROSS THIS REGION INDICATES MODERATE / VEERING
DEEP-LAYER WIND FIELD SUPPORTIVE OF SUPERCELL STORMS.  EXPECT ANY
DEVELOPING STORMS TO BECOME SEVERE...WITH LOCALLY DAMAGING WINDS AND
MARGINAL HAIL POSSIBLE.  IN ADDITION...IT APPEARS THAT AN ISOLATED
TORNADO THREAT EXISTS AS WELL...AS MEAN WIND WOULD SUGGEST ENEWD
STORM MOVEMENT -- POTENTIALLY ALONG WEDGE FRONT AND ASSOCIATED
BAROCLINIC VORTICITY AXIS.

..GOSS.. 04/12/2004

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

ATTN...WFO...ILM...CHS...CAE...JAX...FFC...

33668219 34168076 34597887 34317781 34027785 33757882
33127921 32128090 31418128 31658180 32978233

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 12, 2:18 AM EDTMesoscale DiscussionSPCChatham, Effingham, Screven87 min
Apr 12, 2:25 PM EDTTornado WatchSPCBaldwin, Bleckley, Burke, Columbia, Emanuel, Glascock and 19 more6 hr
Apr 12, 2:33 PM EDTMesoscale DiscussionSPCCalhoun, Chattahoochee, Clay, Decatur, Early, Miller and 5 more117 min
Apr 12, 3:10 PM EDTSevere Thunderstorm WatchSPCBaker, Banks, Barrow, Bartow, Bibb, Butts and 58 more5 hr
Apr 12, 4:44 PM EDTMesoscale DiscussionSPCBaldwin, Bleckley, Burke, Columbia, Dodge, Emanuel and 19 more91 min
Apr 12, 7:31 PM EDTMesoscale DiscussionSPCBaker, Butts, Calhoun, Chattahoochee, Clay, Coweta and 21 more59 min
Apr 12, 7:50 PM EDTSevere Thunderstorm WatchSPCBaker, Baldwin, Ben Hill, Berrien, Bibb, Bleckley and 67 more5 hr

Nearby

Mesoscale Discussions in South Carolina, 2004Mesoscale Discussions in Georgia, 2004Mesoscale Discussions in North Carolina, 2004Every mesoscale discussion in 2004

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.