[MCD] SWOMCD

[MCD at goshenarc.org]

ACUS11 KWNS 162242
SWOMCD
SPC MCD 162238 
NCZ000-SCZ000-GAZ000-ALZ000-170045-

MESOSCALE DISCUSSION 2227
NWS STORM PREDICTION CENTER NORMAN OK
0538 PM CDT THU SEP 16 2004

AREAS AFFECTED...ERN AL...NRN/CNTRL GA...SC

CONCERNING...TORNADO WATCH 828...830...

VALID 162238Z - 170045Z

BRIEF TORNADOES ARE STILL POSSIBLE THIS EVENING.  TORNADO WATCHES
828/830 WILL EXPIRE AT 01Z.  IT IS NOT CERTAIN IF ANY EXTENTIONS
WILL BE NECESSARY.  

HIGHEST PROBABILITIES FOR BRIEF TORNADOES APPEAR TO BE SHRINKING IN
AREAL COVERAGE THIS EVENING WITH THE GREATEST THREAT ACROSS
CNTRL/NERN GA AND CNTRL SC.  22Z MESOANALYSIS PLACED TROPICAL STORM
IVAN OVER NCNTRL AL WITH A WARM FRONT SITUATED EWD ACROSS NRN GA
INTO CNTRL SC. STRONGEST SPIRAL RAINBAND WAS ARCING SWD FROM JUST
EAST OF KATL-KMCN.  OTHER TSTMS...WHICH HAVE EXHIBITED LOW-LEVEL
ROTATION...WERE MIGRATING RAPIDLY NWWD INTO UPSTATE SC VCNTY KAND. 
STRONGEST LOW LEVEL SHEAR EXISTS ALONG THE WARM FRONT...ESPECIALLY
WHERE THESE SPIRAL RAINBANDS INTERSECT FROM 30 E KATL-KAND.  

FARTHER EAST OVER ERN SC...CONVECTION WILL LIKELY BE MORE TIED TO
DIURNAL INFLUENCES AND THE TORNADO THREAT MAY NOT MATERIALIZE THIS
EVENING.  GIVEN THAT THE TROPICAL STORM IS HEADING SLOWLY NWD TOWARD
STRONGEST PRESSURE FALL AXIS INTO NRN AL/MIDDLE TN...THE MOST
INTENSE SPIRAL RAINBANDS SHOULD REMAIN ALONG/WEST OF THE SAVANNAH
RIVER THIS EVENING.

IT IS NOT CLEAR WHETHER A SMALL ADDITIONAL TORNADO WATCH WILL BE
NEEDED AFTER 01Z.  ETA 3-HR PRESSURE FIELDS SEEM TO BE WEAKENING
IVAN TOO RAPIDLY AND WOULD ARGUE FOR SLIGHTLY STRONGER LOW-LEVEL
SHEAR THROUGH THE REMAINDER OF THE EVENING OVER NRN GA...UPSTATE SC
AND PERHAPS ADJOINING WRN NC/ERN TN.  WILL MONITOR THE RAINBANDS
THROUGH 01Z AND IF INTENSITY OR COVERAGE REMAINS THE SAME...AN
ADDITIONAL WW MAY BE REQUIRED.

..RACY.. 09/16/2004

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

ATTN...WFO...RAH...ILM...CHS...CAE...GSP...JAX...FFC...TAE...BMX...HUN...

31868493 32648506 33258585 33438656 34938630 34938256
34657889 31907951 

WWWW