Alert archive / Georgia / Mesoscale Discussions in 2004

Mesoscale Discussion 101

February 6, 20046 counties in Florida; 29 counties in Georgia; 15 counties in South Carolina

The Storm Prediction Center issued this mesoscale discussion at Feb 6, 2004, 4:23 PM EST for 6 counties in Florida; 29 counties in Georgia; 15 counties in South Carolina. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Feb 6, 2004, 4:23 PM EST (21:23 UTC)
Expired: Feb 6, 2004, 6:30 PM EST
In force: 2 hr
Issued by: the Storm Prediction Center

All 50 counties

Baker County, FL, Columbia County, FL, Hamilton County, FL, Jefferson County, FL, Madison County, FL, Suwannee County, FL, Appling County, GA, Atkinson County, GA, Bacon County, GA, Brantley County, GA, Brooks County, GA, Bryan County, GA, Bulloch County, GA, Camden County, GA, Candler County, GA, Charlton County, GA, Chatham County, GA, Clinch County, GA, Coffee County, GA, Echols County, GA, Effingham County, GA, Evans County, GA, Glynn County, GA, Jeff Davis County, GA, Lanier County, GA, Liberty County, GA, Long County, GA, Lowndes County, GA, McIntosh County, GA, Pierce County, GA, Screven County, GA, Tattnall County, GA, Toombs County, GA, Ware County, GA, Wayne County, GA, Allendale County, SC, Bamberg County, SC, Beaufort County, SC, Berkeley County, SC, Clarendon County, SC, Colleton County, SC, Dorchester County, SC, Florence County, SC, Georgetown County, SC, Hampton County, SC, Horry County, SC, Jasper County, SC, Marion County, SC, Orangeburg County, SC, Williamsburg County, SC

The radar

The Charleston,SC radar (KCLX), 68 km from the middle of the area, began a volume at 21:24 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.

Tornado Watch 10Feb 6, 6:00 PM EST

The nearest sounding before it

Charleston AFB, SC (KCHS), launched 12:00Z, 9.4 hours before the alert went out and 151 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 148 J/kg
Mixed-layer CIN: -8 J/kg
Mixed-layer LCL: 584 m above ground
0-6 km bulk shear: 54 kt
0-1 km storm-relative helicity: 244 m²/s²
0-3 km storm-relative helicity: 314 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.

391 
ACUS11 KWNS 062123
SWOMCD
SPC MCD 062123 
NCZ000-SCZ000-GAZ000-FLZ000-062330-

MESOSCALE DISCUSSION 0101
NWS STORM PREDICTION CENTER NORMAN OK
0323 PM CST FRI FEB 06 2004

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

CONCERNING...TORNADO WATCH 9...

VALID 062123Z - 062330Z

ISOLD TORNADO THREAT MAY BE GRADUALLY INCREASING ACROSS A SMALL
GEOGRAPHIC REGION FROM NRN FL/SERN GA INTO SRN/ERN SC LATE THIS
AFTERNOON. A NEW TORNADO WATCH...COVERING PORTIONS OF ERN SC/EXTREME
SERN NC AND THE COASTAL WATERS...MAY BE REQUIRED WITHIN AN HOUR OR
SO.

NARROW THETA-E RIDGE HAS APPEARED IN SURFACE OBJECTIVE ANALYSIS
FIELDS FROM NERN FL NEWD ACROSS SERN GA...AND INTO SRN SC.
MEANWHILE...A BROAD BAND OF DEEP CONVECTION ASSOCIATED WITH A
PREFRONTAL SQUALL LINE CONTINUES TO MOVE EAST AND SLOWLY STRENGTHEN
AS THIS HIGHER THETA-E AIRMASS IS INGESTED. A FEW PERSISTENT
MESOLOWS WITH SPORADIC STRONG CIRCULATIONS HAVE BEEN NOTED WITHIN
THE BROAD CONVECTIVE BAND OVER THE PAST 2 HOURS. ONE OF THESE
LONG-LIVED FEATURES WAS ASSOCIATED WITH A BRIEF TORNADO EARLIER
TODAY OVER THE FL PNHDL. ALTHOUGH SURFACE-BASED INSTABILITY REMAINS
QUITE MARGINAL...SHEAR AND LARGE SCALE ASCENT WILL CONTINUE TO
SUPPORT DAMAGING WIND/ISOLD TORNADO POTENTIAL INTO EARLY EVENING.
THIS POTENTIAL MAY SPREAD INTO ERN SC...AND PERHAPS EXTREME SERN NC
OVER THE NEXT FEW HOURS AND A NEW WATCH COVERING THESE AREAS MAY BE
NEEDED.

..CARBIN.. 02/06/2004

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

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

31138139 29898273 30338408 32168239 33158162 34407910
34067826 32408049

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 6, 8:32 AM EST	Mesoscale Discussion	SPC	Bay, Calhoun, Holmes, Jackson, Okaloosa, Santa Rosa and 2 more	118 min
Feb 6, 1:51 PM EST	Mesoscale Discussion	SPC	Alachua, Baker, Bradford, Clay, Columbia, Duval and 8 more	2 hr
Feb 6, 2:15 PM EST	Tornado Watch	SPC	Columbia, Gadsden, Gulf, Hamilton, Jefferson, Lafayette and 6 more	5 hr
Feb 6, 6:30 PM EST	Mesoscale Discussion	SPC	Columbia, Gadsden, Gulf, Hamilton, Jefferson, Lafayette and 6 more	90 min
Feb 5, 11:55 PM EST	Tornado Watch	SPC	Haralson	5 hr
Feb 6, 6:00 PM EST	Tornado Watch	SPC	Berkeley, Dorchester, Georgetown, Horry, Marion, Williamsburg	5 hr

Nearby

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