Alert archive / Georgia / Mesoscale Discussions in 2008

Mesoscale Discussion 421

March 15, 20084 states

The Storm Prediction Center issued this mesoscale discussion at Mar 15, 2008, 1:21 PM CDT for 4 states. It was in force for 84 min.

The area

The outline as issued.

The facts

Issued
Mar 15, 2008, 1:21 PM CDT (18:21 UTC)
Expired
Mar 15, 2008, 2:45 PM CDT
In force
84 min
Issued by
the Storm Prediction Center
All 127 counties

Calhoun County, AL, Chambers County, AL, Clay County, AL, Cleburne County, AL, Randolph County, AL, Baldwin County, GA, Banks County, GA, Barrow County, GA, Bartow County, GA, Bibb County, GA, Burke County, GA, Butts County, GA, Carroll County, GA, Cherokee County, GA, Clarke County, GA, Clayton County, GA, Cobb County, GA, Columbia County, GA, Coweta County, GA, Dawson County, GA, DeKalb County, GA, Douglas County, GA, Elbert County, GA, Fayette County, GA, Forsyth County, GA, Franklin County, GA, Fulton County, GA, Glascock County, GA, Greene County, GA, Gwinnett County, GA, Habersham County, GA, Hall County, GA, Hancock County, GA, Haralson County, GA, Hart County, GA, Heard County, GA, Henry County, GA, Jackson County, GA, Jasper County, GA, Jefferson County, GA, Jones County, GA, Lamar County, GA, Lincoln County, GA, Lumpkin County, GA, Madison County, GA, McDuffie County, GA, Meriwether County, GA, Monroe County, GA, Morgan County, GA, Newton County, GA, Oconee County, GA, Oglethorpe County, GA, Paulding County, GA, Pike County, GA, Polk County, GA, Putnam County, GA, Richmond County, GA, Rockdale County, GA, Spalding County, GA, Stephens County, GA, Taliaferro County, GA, Troup County, GA, Upson County, GA, Walton County, GA, Warren County, GA, Washington County, GA, White County, GA, Wilkes County, GA, Anson County, NC, Bladen County, NC, Brunswick County, NC, Columbus County, NC, Craven County, NC, Cumberland County, NC, Duplin County, NC, Greene County, NC, Harnett County, NC, Hoke County, NC, Jones County, NC, Lenoir County, NC, Moore County, NC, New Hanover County, NC, Onslow County, NC, Pender County, NC, Richmond County, NC, Robeson County, NC, Sampson County, NC, Scotland County, NC, Union County, NC, Wayne County, NC, Abbeville County, SC, Aiken County, SC, Anderson County, SC, Bamberg County, SC, Barnwell County, SC, Calhoun County, SC, Cherokee County, SC, Chester County, SC, Chesterfield County, SC, Clarendon County, SC, Darlington County, SC, Dillon County, SC, Edgefield County, SC, Fairfield County, SC, Florence County, SC, Greenville County, SC, Greenwood County, SC, Horry County, SC, Kershaw County, SC, Lancaster County, SC, Laurens County, SC, Lee County, SC, Lexington County, SC, Marion County, SC, Marlboro County, SC, McCormick County, SC, Newberry County, SC, Oconee County, SC, Orangeburg County, SC, Pickens County, SC, Richland County, SC, Saluda County, SC, Spartanburg County, SC, Sumter County, SC, Union County, SC, Williamsburg County, SC, York County, SC

The radar

The Columbia radar (KCAE), 64 km from the middle of the area, began a volume at 18:23 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, 6.4 hours before the alert went out and 132 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 2008-03-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 585 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 2008-03-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 71 square meters per square second.1939587897Sfc1 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
585 J/kg
Mixed-layer CIN
-85 J/kg
Mixed-layer LCL
636 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
71 m²/s²
0-3 km storm-relative helicity
38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 151821
SWOMCD
SPC MCD 151821 
NCZ000-SCZ000-GAZ000-ALZ000-151945-

MESOSCALE DISCUSSION 0421
NWS STORM PREDICTION CENTER NORMAN OK
0121 PM CDT SAT MAR 15 2008

AREAS AFFECTED...PORTIONS ERN AL...NRN GA...SC...SRN NC.

CONCERNING...TORNADO WATCH 119...

VALID 151821Z - 151945Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 119 CONTINUES.

TORNADIC SUPERCELL HAS PASSED OVER HALL COUNTY GA...MOVING ROUGHLY
FROM 260 DEG AT 50 KT...SLIGHTLY MORE RIGHTWARD THEN EARLIER AND
INTO INCREASINGLY MOIST/UNSTABLE WARM-FRONTAL AIR.  ASSOCIATED
POTENTIAL FOR SIGNIFICANT TORNADOES...DAMAGING WIND AND HAIL MAY
EXTEND TO ANDERSON COUNTY SC AROUND 19Z...UNION/FAIRFIELD/NEWBERRY
COUNTY AREA AROUND 20Z.  WITH DESTABILIZATION OF AIR MASS CONTINUING
INVOF WARM FRONT E OF THIS STORM...AND LIKELIHOOD OF
ADDITIONAL/UPSTREAM ACTIVITY MOVING ACROSS THIS REGION...ANOTHER WW
MAY BE REQUIRED ACROSS PORTIONS SRN NC AND ERN SC.

VERY INTENSE SFC PRESSURE PERTURBATION WITH MAJOR SUPERCELL
INDICATES INCREASINGLY WELL-DEVELOPED/COLLOCATED MESOLOW.  GVL SFC
OB SHOWED 4 MB PRESSURE FALL IN 22 MIN AND 6 MB IN ONE HOUR...PRIOR
TO 40 KT SFC GUST WITH STORM OUTFLOW...THEN 5 MB RISE IN NEXT 7 MIN
THEREAFTER.  THIS LOW SHOULD PROCEED EWD ALONG WARM FRONT ACROSS NRN
SC THROUGH NEXT 2-3 HOURS...THEN EWD OVER ADJOINING PORTIONS SRN NC.
 ASSOCIATED ISALLOBARIC FORCING WILL MAINTAIN FAVORABLY BACKED WINDS
AND ENLARGED LOW LEVEL HODOGRAPHS ALONG WARM FRONT...WITH MODIFIED
18Z RAOBS AND RUC SOUNDINGS SHOWING MLCAPES AROUND 1000 J/KG IN
PROSPECTIVE INFLOW LAYER.  THIS MAY SUPPORT ADDITIONAL SUPERCELL
FORMATION FROM ACTIVITY DEVELOPING AHEAD OF INITIAL/PRIMARY STORM AS
WELL.
MEANWHILE SUPERCELL/TORNADO THREAT WILL CONTINUE INVOF BOUNDARY
ACROSS NRN GA AND PERHAPS NERN AL...WITH ADDITIONAL DEVELOPMENT
EVIDENT IN THOSE AREAS.

..EDWARDS.. 03/15/2008

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

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

33547902 32768366 32818558 33498629 34008580 35128226
35527772 35137690 34667697 34327770 33867798 33887840
33767879

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 14, 7:11 PM CDTMesoscale DiscussionSPCAutauga, Barbour, Blount, Bullock, Calhoun, Chambers and 18 more64 min
Mar 15, 12:39 AM CDTMesoscale DiscussionSPCBlount, Calhoun, Cherokee, Clay, Cleburne, Colbert and 22 more66 min
Mar 15, 12:56 AM CDTSevere Thunderstorm WatchSPCAutauga, Bibb, Blount, Calhoun, Chambers, Cherokee and 38 more6 hr
Mar 15, 2:57 AM CDTMesoscale DiscussionSPCCherokee, Cleburne, Randolph93 min
Mar 15, 4:30 AM CDTMesoscale DiscussionSPCColbert, Franklin, Marion90 min
Mar 15, 6:58 AM CDTMesoscale DiscussionSPCBlount, Cherokee, Colbert, Cullman, DeKalb, Etowah and 11 more62 min
Mar 15, 7:02 AM CDTSevere Thunderstorm WatchSPCBlount, Calhoun, Cherokee, Cleburne, Colbert, Cullman and 16 more4 hr
Mar 15, 9:38 AM CDTMesoscale DiscussionSPCCalhoun, Cherokee, Cleburne, DeKalb, Etowah, Randolph and 1 more67 min
Mar 15, 10:02 AM CDTTornado WatchSPCAutauga, Bullock, Calhoun, Chambers, Cherokee, Chilton and 15 more8 hr
Mar 15, 10:23 AM CDTMesoscale DiscussionSPCColbert67 min
Mar 15, 12:22 PM CDTMesoscale DiscussionSPCBullock, Calhoun, Chambers, Clay, Cleburne, Coosa and 8 more83 min
Mar 15, 2:08 PM CDTMesoscale DiscussionSPCCleburne67 min
Mar 15, 2:39 PM CDTMesoscale DiscussionSPCBibb, Blount, Cullman, DeKalb, Fayette, Franklin and 12 more2 hr
Mar 14, 10:03 PM CDTMesoscale DiscussionSPCBaldwin, Butts, Clayton, Cobb, DeKalb, Douglas and 26 more57 min
Mar 15, 3:28 AM CDTSevere Thunderstorm WatchSPCBanks, Barrow, Bartow, Butts, Carroll, Chattooga and 42 more3 hr
Mar 15, 6:18 AM CDTMesoscale DiscussionSPCBurke, Columbia, Glascock, Hancock, Jefferson, Jenkins and 7 more117 min
Mar 15, 3:36 PM CDTTornado Watch PDSSPCBaldwin, Barrow, Bibb, Bleckley, Bryan, Bulloch and 73 more8 hr
Mar 15, 4:56 PM CDTMesoscale DiscussionSPCAppling, Atkinson, Bacon, Ben Hill, Berrien, Bleckley and 40 more64 min
Mar 15, 5:17 PM CDTMesoscale DiscussionSPCBanks, Bartow, Cherokee, Cobb, Dawson, Floyd and 14 more28 min
Mar 15, 6:41 PM CDTMesoscale DiscussionSPCBaldwin, Bibb, Bleckley, Bulloch, Burke, Butts and 52 more64 min
Mar 15, 10:30 AM CDTMesoscale DiscussionSPCAnson, Bladen, Brunswick, Columbus, New Hanover, Pender and 4 more60 min
Mar 15, 5:35 PM CDTMesoscale DiscussionSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 17 more25 min
Mar 15, 5:59 PM CDTTornado WatchSPCBeaufort, Bertie, Camden, Carteret, Chowan, Craven and 19 more4 hr

Nearby

Mesoscale Discussions in Georgia, 2008Mesoscale Discussions in South Carolina, 2008Mesoscale Discussions in North Carolina, 2008Every mesoscale discussion in 2008

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.