Severe Thunderstorm Warning 33, NWS Greenville-Spartanburg, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
215 PM EDT SAT MAY 13 2000

MODELS ARE FAIRLY CONSISTENT WITH OVERALL WEATHER FEATURES DURING
THE NEXT 48 HOURS. UPPER RIDGE AXIS ALONG THE EAST COAST THIS
MORNING WILL MOVE OFF TO THE EAST AS A LARGE UPPER VORTEX ROTATES
ACROSS EASTERN CANADA. THIS BIG UPPER LOW WILL MOVE SLOWLY ON SUNDAY
INTO MONDAY...KEEPING A RATHER BROAD UPPER TROF OVER THE EASTERN
HALF OF THE UNITED STATES THROUGH MONDAY...ALLOWING OUR TEMPS TO
RETURN TO MORE SEASONABLE LEVELS.

MAIN FORECAST PROBLEM WILL BE THE POTENTIAL FOR THUNDERSTORMS IN THE
NEAR TERM...AND TO A LESSER EXTENT...TEMPS. KGSP RADAR SHOWS A FEW
TSRA DEVELOPING OVER WRN NC MTNS AS OF 18Z. SURFACE ANALYSIS SHOWS
LOW LEVEL MOISTURE POOLING ALONG LEE SIDE TROF. ETA SHOWS AN AREA OF
LOW LEVEL MOISTURE FLUX CONVERGENCE AND CAPE ABOVE 1500 J/KG AT 00Z
STRETCHING ACROSS THE PIEDMONT. LATEST THINKING IS THAT TSRA
DEVELOPING OVER THE MOUNTAINS WILL FURTHER DEVELOP WHEN THEY
ENCOUNTER THE GREATER INSTABILITY ALONG AND EAST OF THE LEE TROF
LATE THIS AFTERNOON AND EARLY THIS EVENING. MICROBURST POTENTIAL
STILL APPEARS TO BE THERE AS WELL. WILL TENTATIVELY PLAN ON
INCLUDING A SCATTERED TSRA CHANCE OVER THE PIEDMONT ZONES FOR THIS
EVENING. SURFACE FRONT SHOULD CROSS THE FORECAST AREA IN THE 00Z TO
03Z TIME FRAME ENDING THE THREAT.

THE REMAINDER OF THE FORECAST LOOKS RELATIVELY BENIGN AS HIGH
PRESSURE BUILDS IN SUNDAY AND MONDAY. WE MAY SEE A FEW CLOUDS IN THE
MOUNTAINS ON SUNDAY...BUT MOST AREAS SHOULD BE CLEAR/SUNNY THROUGH
MONDAY MORNING. SOME HIGH LEVEL MOISTURE IS PROGGED TO MOVE THRU
MONDAY AFTERNOON BUT WE SHOULD STILL BE MOSTLY SUNNY. THE ONLY
SIGNIFICANT DIFFERENCE IN GUIDANCE TEMPS IS ON SUNDAY. PREFER THE
WARMER FWC NUMBERS WITH LOTS OF SUN AND SOME DOWNSLOPE.

AS FOR THE EXTENDED...MRF DROPS A SURFACE BOUNDARY DOWN ACROSS THE
REGION ON TUESDAY NIGHT AND WEDNESDAY WITH A SWATH OF PRECIP...YET
FMR PRECIP CHANCE REMAINS BELOW CLIMO. THINK I WILL IGNORE THE
PRECIP FOR NOW AND LEAVE THE EXTENDED DRY.

...PRELIM NUMBERS...
AVL 51/73/45/74 2000
CLT 60/81/51/80 3000
GSP 57/81/50/80 2000

.GSP...NONE.

MOORE

GAZ018-026-028-029-NCZ034>037-054>057-066>072-082-SCZ004>014-019-
140000-
SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1105 AM EDT SAT MAY 13 2000

HOT AFTERNOON TEMPERATURES...GOOD INSTABILITY AND A WEAK COLD FRONT
APPROACHING FROM THE WEST WILL COMBINE TO GIVE A CHANCE OF
THUNDERSTORMS DURING THE LATE AFTERNOON AND EARLY EVENING HOURS.
BECAUSE OF THE GOOD INSTABILITY...A FEW OF THE THUNDERSTORMS IN
FOOTHILL AND PIEDMONT LOCATIONS...COULD BECOME SEVERE. THE PRIMARY
THREAT WILL BE DAMAGING STRAIGHT LINE WINDS ALTHOUGH DIME TO QUARTER
SIZE HAIL WILL ALSO BE POSSIBLE.

ALTHOUGH THE CHANCE EXISTS IN THE FOOTHILLS AND PIEDMONT OF EXTREME
NORTHEAST GEORGIA AND THE UPSTATE OF SOUTH CAROLINA...UPPER DYNAMICS
WILL GRADUALLY INCREASE THE FURTHER NORTH YOU GO OVER NORTH CAROLINA.

SPOTTER GROUPS SHOULD BE PREPARED TO ACTIVATE QUICKLY LATE THIS
AFTERNOON AND THIS EVENING. DISPATCHERS SHOULD ENSURE COUNTY
EMERGENCY MANAGEMENT OFFICIALS ARE AWARE OF THIS INFORMATION.

RBN