Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 010241
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
1041 PM EDT FRI JUL 31 2015

.SYNOPSIS...
DRY HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT AND WILL REMAIN
IN PLACE THROUGH THE WEEKEND. LOW LEVEL MOISTURE WILL GRADUALLY
RETURN THROUGH NEXT WEEK AS ANOTHER COLD FRONT APPROACHES FROM THE
NORTH.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 1035 PM EDT FRIDAY...INCREASED SKY OVER THE UPPER SAVANNAH
RIVER VALLEY AS LATEST OBS/IR INDICATE PARTLY/MOSTLY CLOUDY STRATUS
IN ASSOCIATION WITH WEAK ISENTROPIC LIFT ATOP THE LEADING EDGE OF
THE INTRUDING HIGH.  REMOVED ALL POPS FROM THE FCST.
OTHERWISE...TWEAKED MIN TEMPS OVERNIGHT WHICH CONSISTED OF MINOR
INCREASES BENEATH THE A FORE MENTIONED CLOUD LAYER WERE RADIATIONAL
COOLING WILL BE LIMITED.

PREVIOUS DISCUSSION...

AS OF 200 PM EDT FRIDAY...A VERY QUIET NEAR-TERM PERIOD IN STORE IN
THE WAKE OF THE FRONT THAT PASSED THROUGH LAST NIGHT. UPPER LOW OVER
THE HUDSON BAY WITH TROUGHING DOWN THE APPALACHIANS WILL REMAIN IN
PLACE THROUGH THE PERIOD WITH VERY LITTLE CHANGE. BASE OF THE TROUGH
SHOULD REACH TO THE NORTHERN PORTION OF THE FORECAST AREA BUT WITH
THE BULK OF THE CWA IN A COL AREA WITH LITTLE TO NO UPPER FLOW
BETWEEN UPPER RIDGING IN THE ATLANTIC AND DESERT SOUTHWEST AND SOUTH
OF THE UPPER LOW. WEAK SHORTWAVE LOOKS TO PUSH THROUGH THE BASE OF
THE TROUGH OVERNIGHT TONIGHT AND EARLY SATURDAY BUT NO REAL SENSIBLE
WEATHER IMPACTS EXPECTED FROM IT.

SOME OF THE HI-RES REFLECTIVITY GUIDANCE DOES WANT TO DEVELOP
ISOLATED CONVECTION ESPECIALLY ACROSS SOUTHERN AND WESTERN ZONES
THIS AFTERNOON AND EVENING...AND AT AFD TIME THERE IS ONE SHOWER
THAT HAS DEVELOPED ACROSS RABUN COUNTY. HAVE NOT INCLUDED ENOUGH
POPS IN GRIDS TO WARRANT SHOWER OR THUNDER MENTION BUT DID KEEP POPS
AROUND 10 PERCENT IN THOSE AREAS. SPC DAY1 OUTLOOK CONTINUES TO KEEP
GENERAL THUNDER ACROSS THE SOUTHERN PORTION OF THE FORECAST AREA.

TEMPERATURES THROUGH THE NEAR-TERM SHOULD BE VERY CLOSE TO SEASONAL
AVERAGES...WITH VERY WEAK CAA BEHIND THE FRONT COMPETING WITH VERY
WEEK DOWNSLOPING...AND THE TWO PROBABLY JUST ABOUT CANCELING EACH
OTHER OUT. THE NOTICEABLE DIFFERENCE WILL BE DUE TO THE DRIER
DEWPOINTS...ALLOWING IT TO FEEL ALMOST PLEASANT OUTSIDE. ENJOY THE
NICE WEEKEND.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 205 PM FRIDAY...THE WEATHER STILL LOOKS EXCEEDINGLY QUIET FOR
MID SUMMER. THE UPPER PATTERN WILL REMAIN ESSENTIALLY UNCHANGED FROM
SATURDAY NIGHT THROUGH MONDAY...WHICH KEEPS THE EAST COAST AT THE
BOTTOM OF AN UPPER TROF AND THE WESTERN CAROLINAS WITH A DRY NW FLOW
ALOFT. THE MODEL GUIDANCE SHOWS HIGH PRESSURE SETTLING DOWN OVER THE
SRN APPLACHIANS FROM SATURDAY NIGHT INTO SUNDAY...THEN FALLING APART
ON MONDAY. SHOWER ACTIVITY SEEMS HIGHLY UNLIKELY OUTSIDE THE MTNS
THRU THE PERIOD...ESPECIALLY WITH SFC DEWPOINTS EXPECTED TO MIX OUT
INTO THE MID/UPPER 50S. HOWEVER...EVEN WITH THE WARM AIR ALOFT...WE
CANNOT RULE OUT A FEW SHOWERS DEVELOPING IN THE MID/LATE AFTERNOON
OVER THE HIGHER TERRAIN. TEMPS SHOULD BE A FEW DEGREES ABOVE
NORMAL...BUT THAT SHOULD NOT POSE ANY HEAT THREAT GIVEN THE
RELATIVELY DRY AIR MASS.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 230 PM FRIDAY...THE MEDIUM RANGE BEGINS WITH THE TROUGH OVER
THE EAST COAST BEGINNING TO LIFT. THIS WILL PLACE THE CWFA IN THE
TRACK OF MULTIPLE SHORTWAVE CROSSING THE OHIO RIVER VALLEY...THOUGH
A LACK OF DEEP MOISTURE WILL PRECLUDE MUCH INSTABILITY. POPS EARLY
THE WEEK WILL THEREFORE BE KEPT MAINLY TO LOW-END CHANCE IN THE
HIGHER TERRAIN...WITH ONLY SLIGHT CHANCE OR LESS IN LOWER
ELEVATIONS. SOME MOISTENING WILL OCCUR GRADUALLY THROUGH THE WEEK AS
THE BERMUDA HIGH EXERTS ITS INFLUENCE...SO POPS INCREASE SLIGHTLY
EACH DAY THROUGH THE END OF NEXT WEEK. A FRONTAL BOUNDARY WILL
PROPAGATE OUT OF THE OHIO RIVER VALLEY BY MID-WEEK...THOUGH IT
APPEARS TO STALL AND BECOME SEMI-STATIONARY BEFORE IT IS ALLOWED TO
INFLUENCE THE CWA. GUIDANCE HAS COME INTO BETTER AGREEMENT ON THE
NEXT FRONTAL PASSAGE BY THE END OF NEXT WEEK...WITH A SURFACE LOW
EJECTING OUT OF THE GREAT LAKES REGION AND ACCOMPANYING COLD FRONT
TRAILING THROUGH THE SOUTHERN APPALACHIANS. THE FRONT WILL PROVIDE
SOME LEVEL OF FORCING...AND WITH SUFFICIENT MOISTURE HAVING BUILT
BACK INTO THE AREA...POPS WERE INCREASED BACK TO JUST ABOVE CLIMO
FOR THURSDAY AND FRIDAY.

GENERAL HEIGHT RISES WILL ALLOW MAX TEMPS TO WARM TO A COUPLE OF
CATEGORIES ABOVE AVERAGE EARLY IN THE PERIOD...FALLING BACK TO JUST
A DEGREE OR TWO ABOVE CLIMO BY THE END OF NEXT WEEK.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT AND ELSEWHERE...VFR THROUGH THE PERIOD AS HIGH PRESSURE
PREVAILS OVERHEAD WITH A COLD FRONT STALLED TO THE SOUTH.
LIGHT/MODERATE NORTHERLY FLOW WILL WEAKEN INTO THE EVENING LEADING
TO LIGHT/CALM WINDS BY MIDNIGHT AT ALL SITES.  SKIES WILL REMAIN SKC
ACROSS MUCH OF WESTERN NC...HOWEVER SOUNDINGS/MOSGUIDE DO FAVOR A
WINDOW OF FEW LOW VFR STRATUS AT KAVL...GENERALLY AROUND 6-8KFT.
THE SAME LOW VFR STRATUS IS PROGGED ACROSS MUCH OF NORTHEAST GA AND
THE SC UPSTATE...HOWEVER CONFIDENCE IS LOW IN PERSISTENCE THUS AS
WITH KAVL...KEPT ONLY MENTION OF FEW 060-070 IN THE SC TAFS.  BEYOND
THAT EXPECTING A FAIRLY NICE TAF DAY ON SATURDAY WITH LIGHT/MODERATE
NORTHERLY WINDS UNDER FEW HIGH LEVEL CLOUDS FOR THE SC SITES WITH
SKC POSSIBLE OVER WESTERN NC.

OUTLOOK...FLIGHT CONDITIONS WILL REMAIN RESTRICTION FREE THROUGH
MUCH OF THE WEEKEND AHEAD OF GRADUALLY INCREASING
PRECIPITATION/RESTRICTION CHANCES THROUGH MID WEEK AS MOIST
SOUTHERLY FLOW RETURNS.

CONFIDENCE TABLE...

            02-08Z        08-14Z        14-20Z        20-00Z
KCLT       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGSP       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAVL       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KHKY       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KGMU       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%
KAND       HIGH 100%     HIGH 100%     HIGH 100%     HIGH 100%

THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)

WWW.WEATHER.GOV/GSP/AVIATION_TABLES

&&

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

&&

$$
SYNOPSIS...PM
NEAR TERM...CDG/TDP
SHORT TERM...PM
LONG TERM...LEV
AVIATION...CDG


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