Alert archive / Georgia / Mesoscale Discussions in 2004

Mesoscale Discussion 342

April 12, 200425 counties in Georgia; 25 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Apr 12, 2004, 4:44 PM EDT for 25 counties in Georgia; 25 counties in South Carolina. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
Apr 12, 2004, 4:44 PM EDT (20:44 UTC)
Expired
Apr 12, 2004, 6:15 PM EDT
In force
91 min
Issued by
the Storm Prediction Center
All 50 counties

Baldwin County, GA, Bleckley County, GA, Burke County, GA, Columbia County, GA, Dodge County, GA, Emanuel County, GA, Glascock County, GA, Greene County, GA, Hancock County, GA, Jefferson County, GA, Jenkins County, GA, Johnson County, GA, Laurens County, GA, Lincoln County, GA, McDuffie County, GA, Putnam County, GA, Richmond County, GA, Screven County, GA, Taliaferro County, GA, Treutlen County, GA, Twiggs County, GA, Warren County, GA, Washington County, GA, Wilkes County, GA, Wilkinson County, GA, Aiken County, SC, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Berkeley County, SC, Calhoun County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Dorchester County, SC, Edgefield County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Kershaw County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, McCormick County, SC, Orangeburg County, SC, Richland County, SC, Saluda County, SC, Sumter County, SC, Williamsburg County, SC

The radar

The Columbia radar (KCAE), 87 km from the middle of the area, began a volume at 20:43 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, 8.7 hours before the alert went out and 181 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.

872 
ACUS11 KWNS 122044
SWOMCD
SPC MCD 122044 
SCZ000-NCZ000-GAZ000-122215-

MESOSCALE DISCUSSION 0342
NWS STORM PREDICTION CENTER NORMAN OK
0344 PM CDT MON APR 12 2004

AREAS AFFECTED...ERN GA / CENTRAL AND ERN SC

CONCERNING...SEVERE THUNDERSTORM WATCH 70...

VALID 122044Z - 122215Z

SEVERE THREAT CONTINUES ACROSS WW AREA.

STORMS HAVE BEEN SLOW TO DEVELOP ACROSS WW THIS
AFTERNOON...APPARENTLY DUE TO WEAK SUBSIDENCE ASSOCIATED WITH
SHORT-WAVE RIDGING IN THE WAKE OF VORT MAX NOW LIFTING NEWD ACROSS
THE CENTRAL APPALACHIANS.

NONETHELESS...UNSTABLE AIRMASS EXISTS SOUTH OF WEDGE FRONT...WHERE
DEEP-LAYER WIND FIELD REMAINS SUPPORTIVE OF SEVERE STORMS /
SUPERCELLS.  ALTHOUGH IT APPEARS ATTM THAT MOST WIDESPREAD
CONVECTIVE DEVELOPMENT OVER THE NEXT COUPLE OF HOURS SHOULD REMAIN
WEST OF WW AREA /WITHIN WW 0071/...THREAT STILL EXISTS FOR A FEW
ISOLATED SUPERCELLS ACROSS WW 0070.

..GOSS.. 04/12/2004

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

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

33528372 34727948 33327901 32138325

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, 1:52 PM EDTMesoscale DiscussionSPCBryan, Bulloch, Burke, Candler, Chatham, Effingham and 7 more113 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, 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 Georgia, 2004Mesoscale Discussions in South 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.