Lake Wind Advisory 13, NWS Greenville-Spartanburg, SC

Elbert County, GA, Franklin County, GA, Habersham County, GA, Hart County, GA, Rabun County, GA, Stephens County, GA, Alexander County, NC, Burke County, NC, Cabarrus County, NC, Caldwell County, NC, Catawba County, NC, Cleveland County, NC, Davie County, NC, Gaston County, NC, Iredell County, NC, Lincoln County, NC, McDowell County, NC, Mecklenburg County, NC, Polk County, NC, Rowan County, NC, Rutherford County, NC, Union County, NC, Abbeville County, SC, Anderson County, SC, Cherokee County, SC, Chester County, SC, Greenwood County, SC, Laurens County, SC, Union County, SC, York County, SC

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
253 AM EST SUN FEB 4 2007

.SHORT TERM /TODAY THROUGH TUESDAY NIGHT/...
TODAY...
MOISTURE BAND ASSOCIATED WITH FRONTAL BOUNDARY OVER THE OHIO/TENN
VALLEYS HAS BEGUN TO ACTIVATE WITH LIGHT PRECIP OVER WESTERN KY
DURING THE PAST COUPLE OF HOURS. SHORT RANGE MODELS BRING THIS
MOISTURE BAND INTO THE WESTERN MTNS LATE THIS MORNING/EARLY THIS
AFTERNOON BEFORE IT DRIES OUT OVER THE HIGH TERRAIN. WILL CONTINUE
CHANCE POPS FOR SNOW SHOWERS...BUT HAVE MOVED THE TIMING TO THE
15-21 Z TIME FRAME.

THE MAIN CONCERN FOR TODAY WILL BE WIND...AS THE LOW TO MID LEVEL
FLOW STRENGTHENS TO THE 40-70 KT RANGE THIS AFTERNOON. COLD
ADVECTION DURING THE AFTERNOON RESULTS IN A RATHER DEEP MIXED LAYER
OVER THE MTNS. IN FACT...NAM FORECAST SOUNDINGS SUGGEST >60 KTS OF
FLOW AT THE TOP OF THE MIXED LAYER THIS AFTERNOON ACROSS PORTIONS OF
THE AREA. THIS CERTAINLY GIVES ONE PAUSE. HOWEVER...SIGNALS ARE VERY
MIXED REGARDING THE POTENTIAL FOR HIGH WIND THIS AFTERNOON. THE
GRADIENT ACROSS THE MTNS IS ON THE ORDER OF 5 MB...WHICH IS
CONSIDERABLY LESS THAN IS TYPICALLY NEEDED FOR A DAMAGING WIND
EVENT. ALSO...THERE IS AN ABSENCE OF THE STRONG PRESSURE FALL/RISE
COUPLET THAT IS TYPICALLY OBSERVED DURING OUR HIGH WIND EVENTS. A
SET UP VERY SIMILAR TO THIS AFTERNOON/S WHICH OCCURRED LAST MONTH
YIELDED WINDS THAT WERE BARELY IN THE LAKE WIND CATEGORY ACROSS THE
MTNS. HOWEVER...THE FLOW IS 10-15 KTS GREATER THAN IN THAT
EVENT...SO WE HAVE DECIDED TO ISSUE A WIND ADVISORY FOR THE HIGHER
TERRAIN.

TONIGHT THROUGH TUESDAY NIGHT...
COLD ADVECTION CONTINUES ACROSS THE FORECAST AREA TONIGHT. WILL KEEP
THE WIND ADVISORY GOING THROUGH THE NIGHT ACROSS THE NC
MOUNTAINS...HIGHLIGHTING THE HIGHER PEAKS AND THE IMMEDIATE LEE
SLOPES AS LOCATIONS SUBJECT TO THE STRONGEST WINDS. WILL RUN THE
LAKE WIND ADVISORY THROUGH MIDNIGHT OUTSIDE OF THE MOUNTAINS. WIND
CHILL VALUES FALL BELOW ADVISORY CRITERIA ABOVE ABOUT 3000 FEET IN
THE MOUNTAINS...AND IF ANYTHING...WITH AN ARCTIC AIRMASS...I/D BET
ON MINS POSSIBLE BEING A LITTLE TOO HIGH IN THE MOUNTAINS. SINCE
THIS IS STILL A SECOND PERIOD EVENT...I WON/T ISSUE THE WIND CHILL
ADVISORY WITH THIS PACKAGE...BUT IT WILL BE MENTIONED IN THE HWO.

DESPITE THE PALTRY LOOKING RH VALUES LONG THE TN BORDER TONIGHT AND
MONDAY MORNING...AN ARCTIC AIRMASS OF THIS KIND ALMOST ALWAYS RESULTS
IN A FAIR AMOUNT OF SNOW SHOWER ACTIVITY ALONG THE WINDWARD SLOPES.
WITH SNOW RATIOS EASILY PUSHING 20 TO 1...A FLUFFY INCH OF SNOW IS
POSSIBLE IN A FEW SPOTS NEAR THE TN BORDER BY MID-DAY ON MONDAY. FOR
NOW WILL CARRY ONLY CHANCE POPS...BUT LATER SHIFTS MAY NEED TO RAISE
THAT. WENT WITH THE MET MOS HIGHS ON MONDAY WHICH ARE CONSIDERABLY
COLDER THAN THE MAV.

DESPITE THE COLD TEMPERATURES ON MONDAY...DEWPOINTS SHOULD MIX OUT
TO THE POINT WHERE RH/S FALL UNDER 25 PERCENT IN MANY LOCATIONS
OUTSIDE OF THE HIGHEST ELEVATIONS. WITH A COUPLE OF DAYS OF DRYING
UNDER OUR BELT...FIRE DANGER MAY BE HIGH ENOUGH TOMORROW TO WARRANT
THE ISSUANCE OF A FIRE WEATHER WATCH FOR SOME AREAS BY LATER
TODAY.

MUCH BELOW NORMAL TEMPS CONTINUE MONDAY NIGHT AND TUESDAY. ON
TUESDAY NIGHT...LOW LEVEL GRADIENT TIGHTENS AHEAD OF A CLIPPER
SYSTEM DROPPING ACROSS THE LOWER OHIO VALLEY. H8 WINDS INCREASE TO
65 KTS OVER THE MTNS ON THE NAM. SINCE THIS WILL BE A STRONGLY
WARM-ADVECTIVE FLOW REGIME...MOST OF THAT SHOULD NOT MIX DOWN TO THE
SURFACE. HOWEVER...WHEN WIND SPEEDS ARE THAT STRONG...THERE COULD
STILL BE PROBLEMS. THERE WILL ALSO BE SOME UPSLOPE PRECIPITATION.
DEEP LAYER FORCING IS WEAK...BUT A LIGHT WINTRY MIX IS STILL
POSSIBLE OVER THE NORTHERN MOUNTAINS TOWARD SUNRISE WED.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
NO CHANGES MADE TO THE FORECAST AFTER TUESDAY NIGHT.

&&

.AVIATION /08Z-06Z/...
MAINLY A WIND FORECAST OVER THE NEXT 24 HOURS...AS DEEP/DRY WEST TO
NORTHWEST FLOW PERSISTS ACROSS THE REGION. WINDS ARE EXPECTED TO
BECOME QUITE GUSTY THIS AFTERNOON...AS LOWER TO MID-TROPOSPHERIC
FLOW INCREASES TO 40-60 KNOTS. EXPECT MOST OF THE TERMINALS TO GUST
IN THE 25 TO 30 KNOT RANGE FOR SEVERAL HOURS THIS AFTERNOON.
PERIODIC GUSTS OF GREATER THAN 30 KNOTS CAN ALSO BE EXPECTED. WINDS
AT KAVL WILL BE QUITE TRICKY...AS THE GRADIENT SUGGESTS A STRONG
WESTERLY (CROSS-VALLEY) COMPONENT. THIS TYPICALLY PREVENTS WINDS
FROM REACHING THE POTENTIAL SUGGESTED BY THE GRADIENT AND WINDS IN
THE MIXED LAYER. THE BALANCE OF THE AFTERNOON SHOULD SEE WINDS OUT
OF THE NORTHWEST...BUT OCCASIONAL 270-300 DEGREE WINDS CAN ALSO BE
EXPECTED.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...LAKE WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT FOR
     GAZ010-017-018-026-028-029.

NC...WIND ADVISORY FROM NOON TODAY TO 6 AM EST MONDAY FOR NCZ033-
     048>053-058-059-062>065-501-503-505-507-509.

     LAKE WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT FOR
     NCZ035>037-056-057-068>072-082-502-504-506-508-510.

SC...LAKE WIND ADVISORY FROM NOON TODAY TO MIDNIGHT EST TONIGHT FOR
     SCZ001>014-019.

&&

SHORT TERM...JDL/MCAVOY
LONG TERM...MCAVOY
AVIATION...JDL

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
348 PM EST SAT FEB 3 2007

NCZ033-048>053-058-059-062>065-501-503-505-507-509-042100-
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
RUTHERFORD MOUNTAINS-POLK MOUNTAINS-
348 PM EST SAT FEB 3 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE MOUNTAINS OF WESTERN
NORTH CAROLINA.

.DAY ONE...THIS AFTERNOON AND TONIGHT

A LAKE WIND ADVISORY IS IN EFFECT TONIGHT FOR WINDS OF 15 TO 25
MPH WITH GUSTS TO 35 MPH IN AVERY...MITCHELL AND YANCEY COUNTIES.

SNOW IS IN THE FORECAST ALONG THE TENNESSEE BORDER LATE
TONIGHT...BUT ACCUMULATIONS ARE EXPECTED TO BE LIGHT.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

WINDS OF 25 TO 35 MPH ARE EXPECTED IN THE NORTHERN MOUNTAINS ON
SUNDAY...WHILE WINDS UP TO 30 MPH ARE EXPECTED IN THE REST OF THE
MOUNTAINS. WIND GUSTS OF 45 TO 50 MPH ARE EXPECTED ACROSS THE
MOUNTAINS SUNDAY. WINDS WILL REMAIN QUITE GUSTY INTO SUNDAY
EVENING...AND WILL BECOME VERY GUSTY AGAIN ON TUESDAY NIGHT.

THE WIND CHILL INDEX IS EXPECTED TO REACH 5 DEGREES BELOW ZERO ON
SUNDAY NIGHT...MONDAY NIGHT...AND TUESDAY NIGHT.

SNOW IS IN THE FORECAST SUNDAY THROUGH MONDAY...TUESDAY AFTERNOON
AND TUESDAY NIGHT...AND AGAIN THURSDAY NIGHT...MAINLY ALONG THE
TENNESSEE BORDER. ACCUMULATIONS WITH ALL THREE EVENTS ARE EXPECTED
TO BE LIGHT.

SNOW RETURNS TO THE FORECAST YET AGAIN FRIDAY NIGHT THROUGH
SATURDAY. SOME ACCUMULATION IS POSSIBLE WITH THIS EVENT...BUT MUCH
UNCERTAINTY REMAINS REGARDING THE AMOUNT OF MOISTURE AVAILABLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

GAZ010-017-018-026-028-029-NCZ035>037-056-057-068>072-082-502-504-
506-508-510-SCZ001>014-019-042100-
RABUN-HABERSHAM-STEPHENS-FRANKLIN-HART-ELBERT-ALEXANDER-IREDELL-
DAVIE-CATAWBA-ROWAN-CLEVELAND-LINCOLN-GASTON-MECKLENBURG-CABARRUS-
UNION NC-GREATER CALDWELL-GREATER BURKE-EASTERN MCDOWELL-
GREATER RUTHERFORD-EASTERN POLK-OCONEE MOUNTAINS-
PICKENS MOUNTAINS-GREENVILLE MOUNTAINS-GREATER OCONEE-
GREATER PICKENS-GREATER GREENVILLE-SPARTANBURG-CHEROKEE-YORK-
ANDERSON-ABBEVILLE-LAURENS-UNION SC-CHESTER-GREENWOOD-
348 PM EST SAT FEB 3 2007

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

GUSTY WINDS OF 15 TO 30 MPH WITH GUSTS TO 45 MPH ARE EXPECTED ON
SUNDAY AND SUNDAY EVENING.

GUSTY WINDS AND DRY AIR WILL ELEVATE FIRE DANGER IN THE FOOTHILLS
AND PIEDMONT OF WESTERN NORTH CAROLINA ON SUNDAY.

SNOW IS IN THE FORECAST FRIDAY NIGHT AND SATURDAY MORNING. SOME
ACCUMULATION IS POSSIBLE WITH THIS EVENT...BUT MUCH UNCERTAINTY
REMAINS REGARDING THE AMOUNT OF MOISTURE AVAILABLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME.

07