High Wind in Georgia, December 23, 2004

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1007 PM EST WED DEC 22 2004

.SHORT TERM (REST OF TONIGHT)...
THE LARGE PRECIP SHIELD WITHIN BROAD AREA OF STRONG UPGLIDE
CONTINUES TO INCH SLOWLY EASTWARD ACROSS THE WESTERN PART OF THE
CWFA ATTM. AS THE LOW LEVEL JET STRENGTHENS AND TRANSLATES EAST
OVERNIGHT...RAIN WILL BECOME MORE WIDESPREAD AND HEAVIER. RAINFALL
AMOUNTS WILL BE ENHANCED ALONG THE SOUTHERN ESCARPMENT...AS A 50-60
KT SOUTHEAST LLJ BECOMES ESTABLISHED. HOWEVER...STRONG CONVECTION
CONTINUES TO MOVE ALONG THE GULF COAST THIS EVENING...AND SHOULD
PERSIST THERE OVERNIGHT...PROVIDING SOME IMPEDIMENT TO MOISTURE
TRANSPORT INTO THE AREA. IN ADDITION...AS THE UPPER TROUGH LIFTS OUT
LATER TONIGHT...THE STRONGEST DEEP LAYER FORCING WILL PASS NORTHWEST
OF THE AREA. THEREFORE THERE IS QUITE A BIT OF UNCERTAINTY REGARDING
THE AMOUNT OF RAIN THAT WILL FALL OVERNIGHT...AND SEE NO CONCLUSIVE
EVIDENCE TO PROMPT AN EXPANSION OF THE CURRENT FLOOD WATCH.
HOWEVER...WILL MENTION THE POTENTIAL FOR HEAVY RAIN IN THE UNWATCHED
ESCARPMENT ZONES.

AS FAR AS THE WIND...60 KNOT JETS TYPICALLY DONT NEED MUCH OF A
BOOST FROM CONVECTION TO PRODUCE WIND DAMAGE IN THE MNTNS...SO WILL
LEAVE THE HIGH WIND WARNING ALONE. THE LATEST ETA IS DOWNRIGHT
SCARY...AS IT ADVERTISES SOME 70 KNOT WINDS AT A FEW GRID POINTS IN
THE PIEDMONT BY 12Z. IF THERES MORE CONVECTION THAN ANTICIPATED
LATE TONIGHT...WE COULD WIND UP WITH WIND PROBLEMS IN THE LOWER
ELEVATIONS AS WELL. FOR NOW...WILL STAY THE COURSE WITH CURRENT
WARNINGS BUT PASS ALONG CONCERNS TO THE MID SHIFT.

&&

.PREVIOUS DISCUSSION...
THE FOLLOWING WAS ORIGINALLY ISSUED AT 218 PM EST WED DEC 22 2004

SHORT TERM (TONIGHT THROUGH SATURDAY)...
UPPER LEVEL TROUGH OVER CENTER OF CONTINENT AND RIDGE DOWNSTREAM
OVER ATLANTIC TO AMPLIFY AND PROGRESS THIS PACKAGE. GRADIENT AND
GULF INFLOW INCREASE IN ADVANCE OF COLD FRONT APPROACHING AREA.
EXPECT S WINDS TO COME UP RAPIDLY TONIGHT...ESPECIALLY MOUNTAINS...
INCREASING UPSLOPE COMPONENT. RAINFALL OF AROUND 2 INCHES ON
SOUTHERN BLUE RIDGE ESCARPMENT MARGINAL FOR FLOODING...AND WILL
ISSUE FLOOD WATCH TONIGHT AND THU MORNING FOR THIS AREA. WIND GUSTS
IN MOUNTAINS SHOULD EASILY FALL INTO WIND ADVISORY CRITERIA...BUT
WITH SCATTERED CONVECTION EXPECTED AS ATMOSPHERE DESTABILIZES IN
WARM/MOIST ADVECTION...HIGHER WINDS ALOFT COULD MIX DOWN. WILL ISSUE
HIGH WIND WARNING ALL MTS FOR TONIGHT...MAINLY FOR CONVECTIVE GUSTS.
PREFER SLOWER FRONTAL TIMING OF ETA...AND WILL CARRY POPS THROUGH
THU MORNING. TEMPERATRURES MILD TONIGHT AND SAT MORNING IN WARM
ADVECTION.

BY AFTERNOON POPS LIMITED TO I-77 AND TN LINE IN NW FLOW. PLENTY OF
COLD ADVECTION INTO NC MTS...AND BY 21Z 850 MB TEMPS BELOW 0.
PROBLEM IS THAT TOP OF MOIST LAYER AT 18Z BARELY COLD ENOUGH FOR
SNOW AT -8 DEG C...AND BY 21Z DRYING FROM TOP DOWN LEAVES MOIST
LAYER NO COLDER THAN -5 DEG C. WILL CARRY SNOW ABOVE 5000 FT FROM
18Z TO 21Z...THEN END PRECIP...HOLDING ON TO CLOUDS TN LINE. DRYING
THU NIGHT WITH MIN TEMPEREATURES BELOW FREEZING. MAX TEMPERATURES 10
TO 15 DEGREES COLDER FRI THAN THU AS WIND VEERS MORE PARALLEL TO
MTS. FRI AFTERNOON AND EVENING MOISTURE ALONG REMAINS OF ANOTHER
COLD FRONT REACHES MTS. COLD ENOUGH FOR ALL SNOW...BUT MOISTURE
DIMINISHING AS IT ARRIVES. WILL CARRY ONLY SLIGHT CHANCE SNOW TN
LINE FOR NOW. MEANWHILE...MOISTURE AND CLOUDS INCREASE E PORTION AS
IMPULSES MOVE NE OVER STALLED OUT FRONT ON GULF STREAM. DRYING FRI
NIGHT AND SAT AS SURFACE ERIDGE BUILDS INTO AREA...WITH TEMPERATURES
EVEN COLDER BY ABOUT 5 DEG F.

LONG TERM (SATURDAY NIGHT THROUGH WEDNESDAY)...
MDLS IN GENERAL AGREEMENT SUN THRU TUE. RIDGING SFC AND ALOFT BUILD
INTO THE AREA AND DRY COOL FCST PREVAILS. GFS THEN DEVIATES FROM MDL
CONSENSUS BY DEVELOPING DEEP TROF OVER THE CENTRAL US ALLOWING SFC
HIGH TO MOVE EAST AND DEEP SLY TO SWLY FLOW TO DEVELOP. THIS BRINGS
GULF AND ATLANTIC MOISTURE INTO THE REGION AHEAD OF A COLD FRONT
MOVING TOWARD THE AREA AND CHC POP FOR WED. HAVE PLAYED DOWN THIS
SCENARIO GOING CLOSER TO ECMWF GUIDANCE AS SUGGESTED BY HPC. DID ADD
A SILENT 20 POP TO THE GRIDS FOR WED AND WED NIGHT TO BE IN
COLLABORATION TOLERANCE WITH OUR NEIGHBORS.

OPERATIONAL TEMP GUIDANCE STARTS OUT CLOSE TO ENSEMBLE MEAN THEN
DEVIATES SIGNIFICANTLY HIGHER DUE TO SWLY FLOW AND RISING
THICKNESSES. SINCE THIS SCENARIO GENERALLY DISREGARDED HAVE FOLLOWED
HPC TREND IN LATER PERIODS OF SLOWER WARMING TREND CLOSER TO THE
ENSEMBLE MEAN EACH DAY WHICH IS NEAR THEN JUST ABOVE NORMAL.

AVIATION...
AFTER A QUICK SHOT OF MVFR CIGS LATE THIS MORNING AND EARLY THIS
AFT...LOW VFR CIGS SHOULD CONTINUE ACROSS THE AREA UNTIL EVENING.
ATMOS QUICKLY SATURATES LATE THIS AFTERNOON AS DEEP SLY TO SELY FLOW
DEVELOPS. SHOWERS AND MVFR CIGS/VSBY MOVE IN EARLY THIS EVENING.
GOOD SLY FLOW...MOISTURE AND WIDESPREAD RAIN WILL HELP CIGS
GRADUALLY FALL INTO THE 1500 FT RANGE ABOUT 06Z THEN IFR ABOUT 09Z.
CANNOT RULE OUT SOME IFR VSBY AT THAT TIME...BUT HAVE HELD OFF FOR
NOW. CANNOT RULE OUT A RUMBLE OF THUNDER OR TWO EITHER...BUT CHANCE
LOW ENOUGH TO KEEP OUT OF TAF ATTM. MDLS DIFFER ON TIMING OF FRONTAL
PASSAGE. HAVE TRENDED TOWARD THE SLOWER ETA SO KEPT MVFR VSBY AND
IFR CIGS THRU 18Z WHILE BRINGING WINDS TO A SWLY DIRECTION. THE
EXCEPTION IS KAVL WHERE WINDS FLIP TO NLY AT 15Z. GFS SUGGESTS VFR
AND WLY WINDS MOST TAF SITES BY 15Z BUT DISCOUNTED FOR NOW.
&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLOOD WATCH FOR ZONES GAZ010-017-018 TONIGHT AND THURSDAY LATE
     MORNING.
  ...HIGH WIND WARNING FOR ZONES GAZ010-017 TONIGHT AND THURSDAY LATE
     MORNING.
  ...LAKE WIND ADVISORY FOR ZONES GAZ018-026-028-029 UNTIL 6 AM EST.
NC...FLOOD WATCH FOR ZONES NCZ062>065 TONIGHT AND THURSDAY LATE
     MORNING.
  ...HIGH WIND WARNING FOR ZONES NCZ033-048>053-058-059-
     062>065 TONIGHT AND THURSDAY LATE MORNING.
  ...LAKE WIND ADVISORY FOR ZONES NCZ035-037-038-056-057-
     066>072-082 UNTIL 6 AM EST.
  ...WIND ADVISORY FOR ZONES NCZ034-054-055 TONIGHT AND THURSDAY LATE
     MORNING.
SC...FLOOD WATCH FOR ZONES SCZ001>006 TONIGHT AND THURSDAY LATE
     MORNING.
  ...HIGH WIND WARNING FOR ZONES SCZ001>003 TONIGHT AND THURSDAY LATE
     MORNING.
  ...LAKE WIND ADVISORY FOR ZONES SCZ004>014-019 UNTIL 6 AM EST.
&&

SHORT TERM (UPDATE)...LANE

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
510 AM EST WED DEC 22 2004

GAZ010-017-018-026-028-029-NCZ033>037-048>059-062>072-082-SCZ001>014-
019-231009-
ABBEVILLE SC-ALEXANDER NC-ANDERSON SC-AVERY NC-BUNCOMBE NC-BURKE NC-
CABARRUS NC-CALDWELL NC-CATAWBA NC-CHEROKEE SC-CHESTER SC-
CLEVELAND NC-DAVIE NC-ELBERT GA-FRANKLIN GA-GASTON NC-GRAHAM NC-
GREATER GREENVILLE SC-GREATER OCONEE SC-GREATER PICKENS SC-
GREENVILLE MOUNTAINS SC-GREENWOOD SC-HABERSHAM GA-HART GA-HAYWOOD NC-
HENDERSON NC-IREDELL NC-LAURENS SC-LINCOLN NC-MACON NC-MADISON NC-
MCDOWELL NC-MECKLENBURG NC-MITCHELL NC-NORTHERN JACKSON NC-
OCONEE MOUNTAINS SC-PICKENS MOUNTAINS SC-POLK NC-RABUN GA-ROWAN NC-
RUTHERFORD NC-SOUTHERN JACKSON NC-SPARTANBURG SC-STEPHENS GA-
SWAIN NC-TRANSYLVANIA NC-UNION SC-UNION NC-YANCEY NC-YORK SC-
510 AM EST WED DEC 22 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN NORTH CAROLINA...
UPSTATE SOUTH CAROLINA...AND EXTREME NORTHEAST GEORGIA.

.DAY ONE...

LOW PRESSURE OVER THE LOWER MISSISSIPPI VALLEY THIS MORNING WILL LIFT
NORTH TO EASTERN TENNESSEE BY MIDNIGHT. AS THE LOW APPROACHES...WINDS
WILL INCREASE AND SHOWERS WILL SPREAD SOUTHWEST TO NORTHEAST ACROSS
THE REGION. A HIGH WIND WATCH (NPWGSP) HAS BEEN ISSUED FOR THIS
EVENING THROUGH THURSDAY MORNING FOR THE NORTH CAROLINA AND NORTHEAST
GEORGIA MOUNTAINS.

.DAYS TWO THROUGH SEVEN...

LOW PRESSURE WILL TRACK NORTHEAST ALONG THE WESTERN SLOPES OF THE
APPALACHIANS WEDNESDAY NIGHT AND THURSDAY. AS THE LOW
PASSES...RAINFALL ACROSS THE REGION IS EXPECTED TO FALL HEAVY AT
TIMES. STORM TOTAL RAINFALL IS EXPECTED TO RANGE FROM 2 TO 3 INCHES
OVER THE HIGHER TERRAIN TO AROUND AN INCH OVER THE PIEDMONT.
SOUTH-FACING MOUNTAIN SLOPES WILL SEE THE GREATEST AMOUNTS...POSSIBLY
TOPPING 4 INCHES. SOME STRONG THUNDERSTORMS MAY  DEVELOP TONIGHT AND
THURSDAY MORNING AHEAD OF A SHARP COLD FRONT. PLEASE SEE THE SEVERE
WEATHER OUTLOOK (SPSGSP) FOR ADDITIONAL DETAILS ON THE RAINFALL AND
THE SEVERE POTENTIAL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

NED