Severe Thunderstorm Warning 2, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
135 AM EST SAT FEB 12 2000

PRIMARY FORECAST CONCERN THIS PACKAGE IS POSSIBILITY OF STRONG
CONVECTION TDA...AND TEMPS W/REMAINS OF WEDGE-RIDGE ON SUN.

AN IMPRESSIVE AREA OF ELEVATED CONVECTION IS APPROACHING THE CWA FROM
THE W/THIS MORNING. THIS TSRA IS IN THE NOSE OF A STRONG THETA E
AXIS AND IN THE HEART OF STRONG WAA ON THE I294 SFC ON THE ETA. THE
AREA OF UPGLIDE ONLY STRENGTHENS OVER THE WRN CWA AS WE APPROACH
12Z...HELPED BY STRONG AGEO MOTION WITH A COUPLED JET. THE MAIN
VORT...INTERESTINGLY...WL LAG THE BEST WAA AND H3 DYNAMICS BY A
GOOD SIX HOURS. WET BULB ZERO AT FFC AT 00Z WAS ABOUT 8500 FEET...
SO WE REALLY DO NOT NEED THE CAA ALOFT THE VORT WOULD IMPART.

BY 18Z...AS THE VORT CROSSES THE CWA...MOISTURE IS STILL RATHER DEEP
WITH LOCAL POP SCHEME GIVING ABOUT A 70 POP FOR THE AFTERNOON.
UPGLIDE ALSO STILL CONTINUES...THOUGH IS NOT AS STRONG AS WE LOSE
THE AGEO COMPONENT INTRODUCED BY THE RETREATING COUPLED JET. THE
QUESTION IS...HOW FAR S WL THE WEDGE RIDGE PUSH BY EARLY AFTN. 06Z
SFC MAP SHOWS RISES OF 2 TO 3 MB OVER THE MID ATLANTIC STATES...NOT
AS HIGH AS I/D LIKE TO SEE TO PUSH RIDGE THOUGH THE ENTIRE CWA.
STILL...THE ETA HAS MOST NON MTN AREAS IN ELY FLOW BY AFTN...AS THE
RUC DOES BY 15Z. THUS...THREAT FOR STUFF ROOTED IN THE BNDRY LAYER
IN THE EARLY AFTN NOT TOO HIGH.

WL KEEP MENTION OF TSRA IN ALL ZONES TDA. PCPN SHOULD TAPER OFF
SOME IN THE AFTN...PARTICULARLY NRN CWA. NOT SURE HOW TO WORD THAT
YET...BUT WL AT LEAST START W/CAT POPS EVERYWHERE. MAY MENTION SOME
W/LARGE HAIL IN THE SRN TIER OF ZONES AND MTNS.

WE WON/T SCOUR OVERNIGHT...SO WHATEVER WE FALL TO BY LATE AFTN
SHOULD BE ABOUT IT FOR LOWS. WL FOLLOW THE ETA SFC WET-BULBS FOR
THIS...WHICH ARE FAIRLY CLOSE TO RAFS. AS FOR P-TYPE PROBLEM. ETA
1000-850 THICKNESS NEVER FALL TO BELOW 1320 TDA...SO NOT CONCERNED
ABOUT THAT.

WHETHER WE WL SCOUR ON SUN IS A TOUGH CALL. THE PREVIOUS SHIFT DIDN/T
THINK SO AND WENT WELL BELOW MOS NUMBERS. H8 FLOW BECOMES QUITE
STRONG OUT OF THE SW BY AFTN...AND EVEN THE ETA LOSES THE WEDGE
RIDGE...ALBEIT LATE. THEN THERE IS THE PROBLEM OF A FEW SHOWERS IN
WAA AHEAD OF NEXT...STRONG SHORT WAVE. WL GO COOLER THAN MOS...BUT
A COUPLE CATS WARMER THAN PREVIOUS SHIFT.

LOOKS LIKE A STRONG MCS SUN NGHT AND EARLY MON. WL PUT MENTION OF
TSRA IN FIRST AND SECOND PERIOD OF THE EXTENDED AS A RESULT. PCPN MAY
BE MOSTLY OVER MON IF AVN TIMING IS RIGHT...BUT WON/T GET THAT
SPECIFIC ATTM.

PRELIMINARY NUMBERS:

AVL 46/36/55 823
CLT 48/38/52 922
GSP 50/40/53 823

.GSP...NONE.

MCAVOY