Alert archive / Georgia / Mesoscale Discussions in 2003

Mesoscale Discussion 429

April 7, 200312 counties in Alabama; 29 counties in Georgia; 8 counties in Mississippi

The Storm Prediction Center issued this mesoscale discussion at Apr 7, 2003, 9:11 AM CDT for 12 counties in Alabama; 29 counties in Georgia; 8 counties in Mississippi. It was in force for 3 hr.

The area

The outline as issued.

The facts

Issued
Apr 7, 2003, 9:11 AM CDT (14:11 UTC)
Expired
Apr 7, 2003, 11:45 AM CDT
In force
3 hr
Issued by
the Storm Prediction Center
All 49 counties

Barbour County, AL, Coffee County, AL, Conecuh County, AL, Covington County, AL, Crenshaw County, AL, Dale County, AL, Dallas County, AL, Escambia County, AL, Henry County, AL, Monroe County, AL, Pike County, AL, Washington County, AL, Ben Hill County, GA, Bibb County, GA, Bleckley County, GA, Calhoun County, GA, Clay County, GA, Crisp County, GA, Dodge County, GA, Dooly County, GA, Dougherty County, GA, Houston County, GA, Johnson County, GA, Lamar County, GA, Laurens County, GA, Lee County, GA, Monroe County, GA, Pulaski County, GA, Quitman County, GA, Randolph County, GA, Stewart County, GA, Sumter County, GA, Telfair County, GA, Terrell County, GA, Treutlen County, GA, Turner County, GA, Twiggs County, GA, Webster County, GA, Wheeler County, GA, Wilcox County, GA, Wilkinson County, GA, Forrest County, MS, George County, MS, Greene County, MS, Jones County, MS, Lamar County, MS, Pearl River County, MS, Perry County, MS, Stone County, MS

The watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 2.2 hours before the alert went out and 248 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, Peachtre/Fal Fld, GA at 12:00Z on 2003-04-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 72 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, Peachtre/Fal Fld, GA at 12:00Z on 2003-04-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 204 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
72 J/kg
Mixed-layer CIN
-90 J/kg
Mixed-layer LCL
989 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
204 m²/s²
0-3 km storm-relative helicity
209 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

782 
ACUS11 KWNS 071412
SWOMCD
SPC MCD 071411 
GAZ000-ALZ000-FLZ000-MSZ000-LAZ000-071645-

MESOSCALE DISCUSSION 0429
NWS STORM PREDICTION CENTER NORMAN OK
0911 AM CDT MON APR 07 2003

AREAS AFFECTED...CENTRAL/SRN GA...SRN AL...SERN MS

CONCERNING...SEVERE THUNDERSTORM POTENTIAL...HEAVY RAINFALL 

VALID 071411Z - 071645Z

SCATTERED TO NUMEROUS TSTMS ARE EXPECTED TO MOVE ACROSS
DISCUSSION AREA NEXT 2-3 HOURS WITH POTENTIAL FOR SUPERCELLS AND
BOWS TO PRODUCE DAMAGING WIND/HAIL AND A FEW TORNADOES.  WW MAY
BE NEEDED.

ALSO...RAIN RATES COMMONLY 2-3 INCHES/HOUR WITH LOCAL RATES
BETWEEN 3-4 INCHES/HOUR IN MOST DENSE CORES.



SURFACE MESOANALYSIS SHOWS QUASISTATIONARY OUTFLOW BOUNDARY FROM
CSG WSWWD TO NEAR PIB...JUST S OF MOST CONVECTION OBSERVED ATTM
ACROSS REGION.	HOWEVER...CAPPING APPEARS MINIMAL...SO ONLY WEAK
LOW LEVEL FORCING NEEDED FOR ADDITIONAL DEVELOPMENT ALONG OUTFLOW
BOUNDARY AND IN MOIST SECTOR TO ITS S.	MODIFIED RAOBS AND RUC
SOUNDINGS SHOW MODEST MIDLEVEL LAPSE RATES 6.5-7.5 DEG C/KM --
BUT WITH INFLOW-SECTOR SURFACE DEW POINTS 68-71 F...SBCAPE
1000-1500 J/KG AND MLCAPE 500-1000 J/KG ESTIMATED.  VERTICAL
SHEAR PROFILES MARGINALLY SUPPORT SUPERCELLS AND BOW ECHOES WITH
45-55 KT 0-6 KM AGL SHEAR EVIDENT IN VWP AND RUC SOUNDINGS. 
HOWEVER...PRONOUNCED SR FLOW WEAKNESSES JUST ABOVE LLJ
LAYER...OBSERVED VEERING OF BOUNDARY LAYER FLOW...AND EXPECTED
WEAKENING OF LLJ EACH SUGGEST STORM ORGANIZATION WILL BE LIMITED
FOR MORE THAN BRIEF DURATION IN INDIVIDUAL CELLS.  IN MID/UPPER
LEVELS...WEAK BUT INCREASING LARGE SCALE ASCENT POSSIBLE BY LATE
MORNING AS MID-UPPER LEVEL PERTURBATION -- NOW EVIDENT IN RAOB
ANALYSES AND MOISTURE CHANNEL IMAGERY OVER DEEP S TX -- MOVES
NEWD TOWARD REGION ALONG SRN PERIPHERY OF 110-120 KT SRN STREAM
JET MAX.



VERY RICH LOW LEVEL  MOISTURE AVAILABLE FOR HEAVY RAIN PRODUCTION
WITH 850 MB DEW POINTS 13-15 DEG C...13-15 G/KG MEAN MIXING
RATIOS AND TOTAL PW BETWEEN 1.5-2 INCHES.  GREATEST THREAT IS
OVER S-CENTRAL AL INTO SWRN GA FROM MONROE/WILCOX COUNTIES AL
ENEWD TOWARD MCN REGION WHERE LARGE/INTENSE RAIN CORES WILL
TRAIN.

..EDWARDS.. 04/07/2003

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

ATTN...WFO...JAX...FFC...TAE...BMX...MOB...JAN...LIX...FFC...BMX...MOB...

31258978 31778903 32668594 33078409 32718250 31828270
31128605 30968762 30488914 30988990 

32168813 32758575 33158410 32758363 32368393 31638678
31628821

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 6, 8:13 PM CDTMesoscale DiscussionSPCBibb, Chilton, Choctaw, Dallas, Fayette, Greene and 8 more2 hr
Apr 6, 9:48 PM CDTMesoscale DiscussionSPCAutauga, Chilton, Choctaw, Clarke, Dallas, Hale and 6 more87 min
Apr 6, 10:15 PM CDTTornado WatchSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 10 more5 hr
Apr 6, 11:39 PM CDTMesoscale DiscussionSPCAutauga, Butler, Choctaw, Clarke, Conecuh, Covington and 11 more2 hr
Apr 7, 1:51 AM CDTMesoscale DiscussionSPCBullock, Butler, Lowndes, Macon, Montgomery54 min
Apr 7, 2:55 AM CDTTornado WatchSPCAutauga, Barbour, Bullock, Chilton, Choctaw, Dallas and 13 more4 hr
Apr 7, 4:49 AM CDTMesoscale DiscussionSPCAutauga, Chambers, Chilton, Coosa, Dallas, Elmore and 11 more3 hr
Apr 7, 9:40 AM CDTTornado WatchSPCBarbour, Bullock, Macon, Pike, Russell5 hr
Apr 7, 11:25 AM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more3 hr
Apr 7, 12:07 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 12:22 PM CDTMesoscale DiscussionSPCBaldwin, Butler, Clarke, Coffee, Conecuh, Covington and 6 more113 min
Apr 7, 3:40 PM CDTSevere Thunderstorm WatchSPCBaldwin, Covington, Escambia, Mobile5 hr
Apr 7, 5:58 PM CDTMesoscale DiscussionSPCBaldwin, Escambia, Mobile2 hr
Apr 7, 10:05 AM CDTSevere Thunderstorm WatchSPCAmite, Forrest, George, Greene, Hancock, Harrison and 11 more6 hr
Apr 7, 11:02 AM CDTMesoscale DiscussionSPCForrest, Lamar, Pearl River, Perry, Stone3 hr
Apr 7, 2:13 PM CDTMesoscale DiscussionSPCHancock, Harrison, Pearl River, Perry, Stone3 hr
Apr 7, 2:36 PM CDTMesoscale DiscussionSPCHancock, Harrison, Pearl River, Perry, Stone114 min

Nearby

Mesoscale Discussions in Georgia, 2003Mesoscale Discussions in Alabama, 2003Mesoscale Discussions in Mississippi, 2003Every mesoscale discussion in 2003

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.