High Wind in Georgia, December 1, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
636 AM EST FRI DEC 1 2006

.SHORT TERM /REST OF TODAY/...
SOME SURFACE WINDS UPSTREAM IN COLD ADVECTION GUSTING TO OVER 50
KTS...NASHVILLE...SO HAVE BUMPED WINDS UP OVER TN BORDER COUNTIES
TO HIGH WIND WARNING CRITERIA. WILL ISSUE UPDATED PRODUCTS SHORTLY.

&&

.PREV DISCUSSION...
 /ISSUED 248 AM EST FRI DEC 1 2006/

SHORT TERM /TODAY THROUGH SUNDAY/...

RESENT TO ADD REST OF FOOTHILLS/PIEDMONT TO LAKE WIND ADVISORY.

CLOSED UPPER LOW OVER MS VALLEY HEADING ENE WHILE SFC LOW
APPROACHES OH VALLEY WITH COLD FRONT ACROSS DEEP S. EXPECT PERIODS
OF RAIN SHOWERS AS MOIST UPGLIDE AND UPSLOPE FLOW MOVES ACROSS CWA
THROUGH THE MORNING HOURS. FCST PRESSURE GRADIENT ENOUGH TO
SUPPORT 50- 65KT WINDS AT 850MB. WITH WARM ADVECTION AND
ISENTROPIC ASCENT AHEAD OF SYSTEM...DO NOT EXPECT STRONGEST WINDS
TO REACH SURFACE OUTSIDE OF CONVECTIVE OUTBREAKS. STRONG SHEAR
ALONG NARROW LINE OF CONVECTION SUGGESTS ISOLD BROKEN S TORNADO
THREAT AS FRONTAL BAND MOVES ACROSS CWA THIS MORNING THROUGH
EARLY-MID AFTN...ESP ACROSS N CWA WHERE SHEAR IS FCST TO BE
GREATER.

DURING BRIEF PERIOD AFTER FROPA STRONG GRADIENT WINDS WILL REACH THE
SFC OVER HIGHER NC MTNS IN COLD ADVECTION. MODELS DO NOT SUPPORT
ENOUGH WIND FOR HIGH WIND WARNING CRITERIA ATTM BUT WILL CONTINUE
TO MONITOR SYSTEM FOR PSBL HWW LATER THIS MORNING.

ONCE SYSTEM MOVES THROUGH...COOL...DRY HIGH PRESSURE BUILDS IN FOR
WEEKEND. MODELS IN FAIR AGREEMENT DEVELOPING WAVE ON FRONT ALONG
SE COAST SUN AND PUSHING IT NE. SOME MOISTURE FROM THIS SYSTEM COULD
WRAP AROUND TO AFFECT SE ZONES WITH INCREASED CLOUDS AND A SLIGHT
CHANCE RAIN LATE IN THE WEEKEND.

LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT THE BEGINNING OF THE MEDIUM RANGE PERIOD...A SHORT WAVE IS
EXPECTED TO PUSH ACROSS THE REGION...BUT WITH VERY LIMITED MOISTURE.
ALTHO THE GRIDS REFLECT A SLIGHT CHANCE OF PRECIP WITH THE PASSAGE
OF THIS FEATURE...NO INDICATION WILL APPEAR IN THE ZFP OTHER THAN
INCREASED CLOUDS. THE MAIN EFFECTS WILL BE FELT AFTER ITS PASSAGE AS
WE REMAIN IN A WNW FLOW ALOFT NEAR THE BOTTOM OF A VERY BROAD LONG
WAVE TROUGH EARLY IN THE WEEK OVER THE ERN US. TEMPS WILL DROP
ANOTHER CATEGORY ON MONDAY...WHICH IS REFLECTED IN THE FORECAST...
AND WILL MODERATE ONLY SLOWLY AS THE FLOW ALOFT BECOMES NEARLY ZONAL
DURING THE MIDDLE PART OF THE WEEK AS HIGH PRESSURE KEEPS US DRY.

LOOKING AHEAD TO THE END OF THE FORECAST...THE 12Z GFS DEVELOPS THE
NEXT SHORT WAVE UPSTREAM BY LATE WEDNESDAY AND LOADS UP THE PRECIP
TO OUR W ON WEDNESDAY NIGHT. THE PROBLEM IS THAT WITH A COLD HIGH
OVER THE PLAINS AND A DAMMING HIGH OVER UPSTATE NY BY THE END OF THE
DAY ON THURSDAY...THE MODEL SUGGESTS SOME POTENTIAL FOR MIXED PRECIP
WITH A SURFACE LOW DARTING TO OUR SOUTH. THIS IS VIEWED WITH
SKEPTICAL INTEREST FOR NOW AND THE FORECAST FOR THURSDAY WILL
ACTUALLY BE KEPT DRY FOR THE TIME BEING.

AVIATION...
RADAR SHOWS THE BACK EDGE OF NORTHWARD MOVING SHOWERS NOW CROSSING
THE NORTH CAROLINA STATE LINE...WITH A RELATIVELY ECHO FREE AREA
UPWIND. AS THE WIND WILL REMAIN UP...VISIBILITY IS EXPECTED TO
IMPROVE AT KCLT ONCE THIS ROUND OF PRECIPITATION ENDS. SOME GUSTS
ARE SHOWING UP IN OBSERVATIONS...AND THE MODELS SUGGEST THAT GUSTS
WILL INCREASE SIGNIFICANTLY OVERNIGHT AS THE GRADIENT AHEAD OF THE
COLD FRONT TIGHTENS FURTHER. DESPITE VERY STRONG 850 MB WINDS...WITH
LIMITED INSTABILITY AND WARM ADVECTION...GUSTS WILL ONLY BE
INCREASED SLIGHTLY IN THIS TAF PACKAGE...APPROACHING THE 30 KNOT
RANGE. CEILINGS ARE QUITE LOW AT ALL SITES BUT KAVL WHERE THE FLOW
IS DOWNVALLEY...AND LITTLE IMPROVEMENT IS SEEN EAST OF THE MOUNTAINS
UNTIL THE WIND STARTS TO VEER JUST BEFORE THE FRONT ARRIVES. LINEAR
SHOWER ACTIVITY IS EXPECTED AHEAD OF THE FRONT THIS MORNING....BUT
SUBSTANTIAL VISIBILITY RESTRICTIONS SHOULD BE BRIEF. A RAPID FRONTAL
PASSAGE IS EXPECTED AROUND MIDDAY...TURNING THE WIND UPVALLEY AT
KAVL...BUT WITH THE ATMOSPHERE QUICKLY DESSICATED FROM THE TOP
DOWN...FEW POST FRONTAL CLOUD ARE EXPECTED. GUSTS WILL BE SLOW TO
DIMINISH THIS AFTERNOON AND EVENING...BUT THIS SYSTEM DOES NOT
MAINTAIN A TIGHT PRESSURE GRADIENT FOR LONG AND BY LATE EVENING THE
VEERING SURFACE WIND SHOULD BECOME TAME.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...LAKE WIND ADVISORY FOR GAZ010-017-018-026-028-029 UNTIL
     MIDNIGHT SATURDAY.
NC...HIGH WIND WARNING FOR NCZ033-048>052-058 UNTIL MIDNIGHT
     SATURDAY.
  ...WIND ADVISORY FOR NCZ034-053>055-059-062>066-501-503-505-507-
     509 UNTIL MIDNIGHT SATURDAY.
  ...LAKE WIND ADVISORY FOR NCZ035>037-056-057-067>072-082-502-504-
     506-508-510 UNTIL MIDNIGHT SATURDAY.
SC...LAKE WIND ADVISORY FOR SCZ001>014-019 UNTIL MIDNIGHT SATURDAY.
&&

SHORT TERM...RB

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
331 AM EST FRI DEC 1 2006

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-020845-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-AVERY-ALEXANDER-
IREDELL-DAVIE-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-
CATAWBA-ROWAN-GRAHAM-NORTHERN JACKSON-MACON-SOUTHERN JACKSON-
TRANSYLVANIA-HENDERSON-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-
CABARRUS-UNION NC-CALDWELL MOUNTAINS-GREATER CALDWELL-
BURKE MOUNTAINS-GREATER BURKE-MCDOWELL MOUNTAINS-EASTERN MCDOWELL-
RUTHERFORD MOUNTAINS-GREATER RUTHERFORD-POLK MOUNTAINS-
EASTERN POLK-OCONEE MOUNTAINS-PICKENS MOUNTAINS-
GREENVILLE MOUNTAINS-GREATER OCONEE-GREATER PICKENS-
GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-ANDERSON-ABBEVILLE-
LAURENS-UNION SC-CHESTER-GREENWOOD-
331 AM EST FRI DEC 1 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST
GEORGIA...PIEDMONT NORTH CAROLINA...WESTERN NORTH CAROLINA AND
UPSTATE SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT

THE CHANCE FOR SHOWERS AND THUNDERSTORMS WILL INCREASE ACROSS THE
WESTERN CAROLINAS AND NORTHEAST GEORGIA EARLY THIS MORNING. A
NARROW BUT STRONG LINE OF CONVECTION WILL APPROACH THE AREA FROM THE
WEST. WINDS IN THE LOWER PART OF THE ATMOSPHERE WILL BECOME VERY STRONG
AND A FEW OF THE HEAVIER SHOWERS AND THUNDERSTORMS MAY TAP THESE
WINDS...PRODUCING LOCALIZED DAMAGE.

THE BEST CHANCE FOR DAMAGING WINDS BEFORE SUNRISE WILL BE OVER THE
AREA TO THE WEST OF TOCCOA...GREENVILLE...AND HICKORY. THE LINE OF
SHOWERS AND THUNDERSTORMS IS EXPECTED TO PUSH EAST ACROSS THE
UPSTATE AND FOOTHILLS DURING THE MORNING HOURS...AND THE WESTERN
PIEDMONT DURING THE MIDDLE PART OF THE DAY. DURING THIS TIME...
LOCALIZED DAMAGING WINDS WILL STILL BE POSSIBLE...ESPECIALLY OVER
THE FOOTHILLS AND PIEDMONT OF NORTH CAROLINA. A FEW BRIEF
TORNADOES WILL NOT BE OUT OF THE QUESTION GIVEN THE AMOUNT OF LOW
LEVEL WIND SHEAR THAT IS EXPECTED.

GRADIENT WINDS WILL INCREASE ACROSS THE ENTIRE AREA. WIND GUSTS
TO 50 TO 55 MPH WILL BE POSSIBLE OVER THE NORTH CAROLINA
MOUNTAINS...WHICH MAY DOWN A FEW TREES AND LARGER BRANCHES. WIND
GUSTS OF 40 MPH WILL BE POSSIBLE OVER THE REST OF THE FORECAST
AREA INTO THE EVENING HOURS. A WIND ADVISORY IS IN EFFECT THROUGH
MIDNIGHT FOR THE NORTH CAROLINA MOUNTAINS. A LAKE WIND ADVISORY IS
IN EFFECT FOR THE REST OF THE FORECAST AREA.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.SPOTTER INFORMATION STATEMENT...
SPOTTERS MAY BE NEEDED THIS MORNING AND EARLY AFTERNOON IF THERE
IS ANY SIGNIFICANT WIND DAMAGE. DISPATCHERS PLEASE BE SURE THAT
EMERGENCY MANAGERS ARE BRIEFED ON THIS PRODUCT.