Frost Advisory 5, NWS Greenville-Spartanburg, SC

566 
WWUS72 KGSP 140225
NPWGSP

URGENT - WEATHER MESSAGE
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1025 PM EDT WED APR 13 2011

NCZ033-048>053-058-059-062>065-501-503-505-141300-
/O.CON.KGSP.FR.Y.0005.110414T0400Z-110414T1300Z/
AVERY-MADISON-YANCEY-MITCHELL-SWAIN-HAYWOOD-BUNCOMBE-GRAHAM-
NORTHERN JACKSON-MACON-SOUTHERN JACKSON-TRANSYLVANIA-HENDERSON-
CALDWELL MOUNTAINS-BURKE MOUNTAINS-MCDOWELL MOUNTAINS-
INCLUDING THE CITIES OF...NEWLAND...SPRUCE PINE...BRYSON CITY...
WAYNESVILLE...ASHEVILLE...SYLVA...FRANKLIN...BREVARD...
HENDERSONVILLE
1025 PM EDT WED APR 13 2011

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM EDT THURSDAY...

A FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM EDT THURSDAY. 

* LOCATIONS...MAINLY THE VALLEYS OF THE NORTH CAROLINA MOUNTAINS.

* TEMPERATURES...IN THE LOWER AND MIDDLE 30S...BUT A BRIEF LIGHT
  FREEZE IS POSSIBLE IN NORMALLY COLDER LOCATIONS.

* WINDS...NORTH UP TO 5 MPH.

* IMPACTS...CERTAIN CROPS AND OTHER TENDER VEGETATION COULD BE
  DAMAGED AS AREAS OF FROST DEVELOP DURING THE OVERNIGHT HOURS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FROST ADVISORY MEANS THAT FROST IS POSSIBLE. SENSITIVE OUTDOOR
PLANTS MAY BE KILLED IF LEFT UNCOVERED.

&&

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
124 PM EDT WED APR 13 2011

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE REGION THROUGH THURSDAY. A COLD
FRONT IS EXPECTED TO APPROACH FROM THE WEST FRIDAY AND REACH THE
CAROLINA COAST BY SATURDAY NIGHT. HIGH PRESSURE WILL THEN FOLLOW
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
1700Z UPDATE...JUST ANOTHER TWEAK TO SKY GRIDS TO REFLECT TREND IN
MTN WAVE CIRRUS INTO EARLY AFTN. TEMPS ARE BEING INFLUENCED BY THE
DENSE CLOUDS...BUT THE CLOUDS ARE THINNING AND DISSIPATING FROM SW
TO NE...SO WILL NOT MAKE MAJOR CHANGES TO TEMP GRIDS. EVERYTHING
ELSE ON TRACK.

1400Z UPDATE...FCST IS ON TRACK. A BRIEF PERIOD OF MTN WAVE CIRRUS
WILL AFFECT THE PIEDMONT FROM SW TO NE LATE THIS MRNG FOR A FEW
HOURS. BUT SHUD BE SUNNY FOR MOST OF THE AFTN. DOWNSLOPE FLOW WILL
WEAKEN...BUT SHUD SEE TEMPS BACK UP ABOVE NORMAL EAST OF THE MTNS
AND NEAR NORMAL IN THE MTNS. SO NO CHANGES EXCEPT TWEAKS TO SKY AND
WINDS.

1100Z UPDATE...LOWERED CIRRUS COVERAGE THIS AFTERNOON AND TONIGHT
PER THE LATEST NAM TIME HEIGHTS.

AS OF 2 AM EDT WEDNESDAY...UPPER LEVEL RIDGING WILL SLOWLY MAKES ITS
WAY INTO OUR AREA FROM THE WEST IN THE WAKE OF THE DEPARTING UPPER
LOW TO OUR NORTHEAST. THE REMAINING LOW LEVEL MOISTURE OVER THE
MOUNTAINS WILL DECREASE TODAY. MODEL TIME HEIGHT SHOW SOME CIRRUS
SPREADING IN FORM THE WEST...MAINLY TONIGHT. WINDS WILL DECREASE AND
VEER FROM NW TODAY TO NE TONIGHT AS HIGH PRESSURE TO THE WEST
ADVANCES. MAXIMUM TEMPERATURES TODAY WILL BE A FEW DEGREES ABOVE
NORMAL AS HEIGHTS RISE ALOFT...AND WEAK DOWNSLOPE FLOW AFFECTS THE
LEE. MINIMUM TEMPERATURES TONIGHT WILL BE A FEW DEGREES BELOW NORMAL
AS COOL HIGH PRESSURE SETTLES IN. NO SITES ARE EXPECTED OT RECEIVE
FREEZING TEMPERATURES TONIGHT...AND RELATIVE HUMIDITY WILL BE TO LOW
FOR FROST IN THE MOUNTAINS.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 300 AM WEDNESDAY...HIGH PRESSURE WILL CROSS THE REGION ON THU.
THERE MAY BE SOME PASSING HIGH CLOUDS..ESPECIALLY IN THE AFTN...BUT
THE DAY OTHERWISE LOOKS VERY PLEASANT. AS THE RIDGE MOVES OFF THE
COAST THU NIGHT...RETURN FLOW WILL DEVELOP OVER THE REGION. MODEL
TIME SECTIONS AND PLAN VIEWS SHOW THAT THE LAYER UP AROUND 5KFT
SATURATES FAIRLY QUICKLY ALONG THE ERN SLOPES OF THE BLUE RIDGE.
THIS COMBINED WITH INCREASING HIGH CLOUD COVER AS THE DEEP LAYER
FLOW SHIFTS TO THE SW MEANS SKIES SHOULD BECOME CLOUDY OVERNIGHT. A
FEW SHRA ARE ALSO A GOOD BET ALONG THE SLOPES OF THE MTNS.

THE NAM/GFS/ECMWF REMAIN IN VERY GOOD AGREEMENT ON THE EVOLUTION OF
THE PATTERN FRI AND SAT. A STRONG UPPER LOW WILL CUT OFF OVER THE
CENTRAL PLAINS EARLY FRIDAY. THE LOW WILL SLOWLY MOVE EASTWARD AND
THEN OPEN UP AND EJECT FAIRLY QUICKLY INTO SRN CANADA BY LATE
SATURDAY. ABUNDANT MOISTURE WILL STREAM NORTHWARD AHEAD OF THIS LOW.
THE GFS PW/S ARE 200 PERCENT OF NORMAL ACROSS THE MTNS AND FOOTHILLS
FRI NIGHT AND SATURDAY MORNING. THE LLVL FLOW WILL BE ON THE ORDER
OF 40 TO 50 KTS...ORIENTED PERPENDICULAR TO THE MTNS. THIS SHOULD
RESULT IN ABUNDANT MODERATE TO HEAVY UPSLOPE SHRA AND A FEW TSTMS
WHICH SHOULD PICK UP IN EARNEST LATE ON FRIDAY...CONTINUE FRIDAY
NIGHT...AND END SOMETIME AROUND NOON ON SATURDAY. THE GFS AND EC
BOTH GENERATE 2 TO 3 INCHES OF RAIN OVER THE BLUE RIDGE AND ADJACENT
FOOTHILL LOCATIONS...WITH CONSIDERABLY LESS PCPN OUT OVER THE
PIEDMONT. THIS PROBABLY WON/T BE ENOUGH TO CAUSE FLOODING
PROBLEMS...BUT I/LL MENTION IT IN THE HWO.

BY SATURDAY AFTN THE SFC FRONT SHOULD BE LOCATED SOMEWHERE OVER THE
FA. THE GFS HAS THE FLOW NICELY BACKED AHEAD OF THE FRONT...WITH
SBCAPE VALUES IN THE 500-1000 RANGE. THE EC LOOKS VERY SIMILAR WITH
EVEN HIGHER CAPE. THERE SHOULDN/T BE MUCH ELEVATED MIXED LAYER AIR
LEFT OVER THE REGION CONSIDERING HOW MOIST THE AIRMASS IS AND HOW
LONG THE UPPER TROUGH WILL HAVE TO ACT ON THE AIRMASS...WHICH SHOULD
RESULT IN MOIST ADIABATIC TEMPERATURE PROFILES. STILL...THERE WILL
BE MORE THAN ADEQUATE SHEAR FOR A FEW SEVERE STORMS DEPENDING ON THE
EXACT TIMING OF THE FRONT. I/LL MENTION THIS IN THE HWO AS WELL.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 125 AM WEDNESDAY...THE ECMWF AND GFS CONTINUE TO BE IN GOOD
AGREEMENT WITH THE SYSTEM ON SATURDAY. THEY BOTH BRING A WET COLD
FRONT ACROSS THE FA...INCLUDING A MODEST AMOUNT OF DESTABILIZATION
OVER THE ERN PART OF THE FA. LOOKS LIKE A GOOD RAINFALL EVENT WITH A
POSSIBLE SEVERE THREAT OVER THE PIEDMONT AND FOOTHILLS. THE GFS HAS
COME AROUND MORE TO THE ECMWF SOLUTION WITH THE UPPER LOW THEREAFTER
AS IT LIFTS FAIRLY QUICKLY INTO ERN CANADA. THIS PUTS THE REGION
UNDER ZONAL FLOW ON SUNDAY...WITH A LOW AMPLITUDE RIDGE BUILDING
OVER THE SE STATES MON AND TUE. THE WEATHER ON SUNDAY LOOKS GREAT.
FAIR AND WARMER WEATHER IS LOOKING MORE PROBABLE FOR MON AND TUE.
HOWEVER...THE LATEST CANADIAN HAS MORE TROFFING OVER THE SE STATES
EARLY NEXT WEEK...SO CONFIDENCE IS STILL A LITTLE LOW ON JUST HOW
DRY WE WILL BE.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AT KCLT...JUST EXPECT PERIODS OF CIRRUS THRU THE PERIOD. NW WND WILL
CONTINUE TO HAVE INTERMITTENT GUSTS ARND 15 KTS. LGT N WND AFTER
SUNSET...GRADUALLY VEERING TO NE...THEN SE AFTER DAYBREAK THU.

AT KAVL...GUSTY NORTHWEST WINDS WILL BECOME LIGHT/CALM THIS EVENING.
JUST A FEW CIRRUS OFF AND ON THRU THE PERIOD. A LACK OF LOW LEVEL
MOISTURE...SO NOT EXPECTING ANY RESTRICTIONS.

ELSEWHERE...LIGHT WINDS...BECOMING BRIEFLY CALM THIS EVENING BEFORE
TAKING ON A NE DIRECTION AFTER MIDNIGHT AS HIGH PRESSURE BUILDS
EAST. A FEW CIRRUS WILL MOVE IN FROM THE WEST TODAY. LOW LEVELS WILL
BE TOO DRY FOR RESTRICTIONS.

OUTLOOK...VFR CONDITIONS EXPECTED THURSDAY NGT. RESTRICTIONS
EXPECTED TO RETURN IN PRECIPITATION FRI AFTN THRU SAT. IMPROVEMENT
ON SUN AS DRIER AIR RETURNS.

&&

.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.

&&

SYNOPSIS...MCAVOY
NEAR TERM...ARK/JAT
SHORT TERM...MCAVOY
LONG TERM...MCAVOY
AVIATION...ARK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
508 AM EDT WED APR 13 2011

GAZ010-017-018-026-028-029-NCZ033-035>037-048>053-056>059-062>065-
068>072-082-501>510-SCZ001>014-019-140915-
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-
508 AM EDT WED APR 13 2011

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

.DAY ONE...TODAY AND TONIGHT.

HAZARDOUS WEATHER IS NOT EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

A COLD FRONT WILL CROSS THE REGION ON SATURDAY. WIDESPREAD RAIN
WILL ACCOMPANY AND PRECEDE THE FRONT. AT THIS TIME...THE HEAVIEST
RAIN IS EXPECTED TO FALL ACROSS THE MOUNTAINS AND FOOTHILLS. THERE
WILL ALSO BE A CHANCE FOR SEVERE STORMS AHEAD OF THE FRONT FRIDAY
NIGHT AND SATURDAY.

.SPOTTER INFORMATION STATEMENT...

NONE.