Alert archive / Georgia / Mesoscale Discussions in 2004

Mesoscale Discussion 2178

September 6, 20045 counties in Florida; 32 counties in Georgia; 11 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Sep 6, 2004, 7:12 PM EDT for 5 counties in Florida; 32 counties in Georgia; 11 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Sep 6, 2004, 7:12 PM EDT (23:12 UTC)
Expired
Sep 6, 2004, 9:15 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
All 48 counties

Baker County, FL, Columbia County, FL, Duval County, FL, Nassau County, FL, Union County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Brantley County, GA, Bryan County, GA, Bulloch County, GA, Burke County, GA, Camden County, GA, Candler County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Effingham County, GA, Emanuel County, GA, Evans County, GA, Glynn County, GA, Jeff Davis County, GA, Jenkins County, GA, Liberty County, GA, Long County, GA, McIntosh County, GA, Montgomery County, GA, Pierce County, GA, Screven County, GA, Tattnall County, GA, Telfair County, GA, Toombs County, GA, Treutlen County, GA, Ware County, GA, Wayne County, GA, Wheeler County, GA, Allendale County, SC, Bamberg County, SC, Barnwell County, SC, Beaufort County, SC, Berkeley County, SC, Charleston County, SC, Colleton County, SC, Dorchester County, SC, Hampton County, SC, Jasper County, SC, Orangeburg County, SC

The radar

The Jacksonville radar (KJAX), 116 km from the middle of the area, began a volume at 23:15 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

Jacksonville, FL (KJAX), launched 12:00Z, 11.2 hours before the alert went out and 114 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, Jacksonville, FL at 12:00Z on 2004-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 830 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jacksonville, FL at 12:00Z on 2004-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 235 square meters per square second.19395878Sfc1 km3 km6 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
830 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
653 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
235 m²/s²
0-3 km storm-relative helicity
235 m²/s²
Significant tornado parameter
1.1
Supercell composite
4.8

Open this sounding in Storm Lab

The text

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

229 
ACUS11 KWNS 062314
SWOMCD
SPC MCD 062312 
SCZ000-GAZ000-FLZ000-070115-

MESOSCALE DISCUSSION 2178
NWS STORM PREDICTION CENTER NORMAN OK
0612 PM CDT MON SEP 06 2004

AREAS AFFECTED...NRN FL...SERN GA...SRN SC

CONCERNING...TORNADO WATCH 805...806...

VALID 062312Z - 070115Z

ISOLATED FEEDER BAND SUPERCELLS ARE EXPECTED TO CONTINUE TO ROTATE
INLAND ACROSS THE COASTAL AREAS OF NERN FL/SERN GA AND SRN SC
TONIGHT AS CENTER OF T.S. FRANCES MOVES SLOWLY NWD OVER SRN GA.
WHILE THE CYCLONE IS VERY LARGE...LATEST OBSERVATIONAL AND SHORT
TERM MODEL DATA APPEAR TO SUGGEST THAT THE STRONGEST LOW THROUGH MID
LEVEL WINDS /50-60KT/ ARE SITUATED WITHIN THE NERN QUADRANT OF THE
STORM...PRIMARILY FROM EXTREME NERN FL NWD ALONG THE ATLANTIC COAST
TO SC. SHEAR AND HELICITY ACROSS THESE AREAS REMAINS FAVORABLE FOR
ROTATING UPDRAFTS WITHIN THE BANDS OF CONVECTION ROTATING AROUND
FRANCES. STORMS MOVING ONSHORE FROM THE GULF STREAM WATERS ALSO
APPEAR TO BE IN PROXIMITY TO GREATER CONVECTIVE INSTABILITY COMPARED
TO CONVECTION FARTHER INLAND BASED ON LTG STRIKE DATA. THUS...IT
SEEMS THAT ANOTHER TORNADO WATCH ALONG THE IMMEDIATE EAST COAST WILL
PROBABLY BE NEEDED IN THE NEXT HOUR.

..CARBIN.. 09/06/2004

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

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

30028133 30038265 32148304 33558166 33347912

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 8:35 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more9 hr
Sep 6, 12:12 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more2 hr
Sep 6, 4:06 AM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 21 more84 min
Sep 6, 4:50 AM EDTTornado WatchSPCAlachua, Baker, Bradford, Clay, Columbia, Dixie and 11 more9 hr
Sep 6, 7:48 AM EDTMesoscale DiscussionSPCBrevard, Charlotte, DeSoto, Hardee, Highlands, Lake and 8 more87 min
Sep 6, 7:55 AM EDTTornado WatchSPCBrevard, Charlotte, Citrus, DeSoto, Glades, Hardee and 21 more6 hr
Sep 6, 12:28 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Brevard, Charlotte, Citrus and 36 more92 min
Sep 6, 1:20 PM EDTTornado WatchSPCAlachua, Baker, Bradford, Brevard, Citrus, Clay and 38 more7 hr
Sep 6, 3:55 PM EDTMesoscale DiscussionSPCAlachua, Baker, Bradford, Clay, Columbia, Duval and 10 more2 hr
Sep 6, 7:45 PM EDTTornado WatchSPCBradford, Clay, Duval, Flagler, Nassau, Putnam and 1 more9 hr
Sep 6, 1:21 AM EDTMesoscale DiscussionSPCRichmond84 min
Sep 6, 1:00 PM EDTTornado WatchSPCAppling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 49 more7 hr

Nearby

Mesoscale Discussions in Georgia, 2004Mesoscale Discussions in South Carolina, 2004Mesoscale Discussions in Florida, 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.