Area Forecast Discussion
Issued by NWS Greer, SC

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000
FXUS62 KGSP 312023
AFDGSP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
423 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 420 PM EDT FRIDAY...MOSTLY SUNNY SKIES CONTINUE TO PREVAIL
ACROSS THE VAST MAJORITY OF THE FCST AREA THIS AFTERNOON WITH ONLY
MINIMAL FAIR WX CU PRESENT.  THE ONLY EXCEPTION BEING ALONG THE
SOUTHERN BLUE RIDGE ESCARPMENT WHERE SOME ENHANCED CU PERSISTS.
LATEST CAM GUIDANCE CONTINUE TO FAVOR A LOW PROBABILITY FOR A SPOTTY
SHOWERS OVER THIS REGION...THUS DID INTRODUCE A 1-2 HOUR WINDOW OF
ISOLATED POPS FOR THESE ZONES THIS AFTERNOON.  OTHERWISE...CURRENT
FCST REMAINS ON TRACK AND THEREFORE NO OTHER CHANGES NEEDED/MADE
WITH THIS UPDATE.

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 /21Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT AND ELSEWHERE...VFR...WITH THE POSSIBLE EXCEPTION OF BRIEF
MVFR FOG AT KHKY BETWEEN 06-12Z SATURDAY BUT CHANCE NOT HIGH ENOUGH
TO INCLUDE IN TAF AT THIS TIME. VERY LITTLE MOISTURE TO WORK WITH IN
THE WAKE OF THE FRONT THIS MORNING SO EXPECT AT BEST FEW TO SCT
CLOUDS AROUND 5-6KFT FOR THIS AFTERNOON...WITH POSSIBLY ANOTHER
ROUND SATURDAY AFTERNOON...BUT MOISTURE IS EVEN MORE LIMITED BY THAT
POINT. COULD SEE PASSING CIRRUS OFF AND ON AS WELL. DO NOT EXPECT
ANY CONVECTION THROUGH THE PERIOD AT THE TAF SITES. WINDS SHOULD
REMAIN GENERALLY N TO NE WITH ONLY BRIEF SWINGS TOWARD E...BUT
REMAINING ON THE N SIDE. COULD SEE SOME OFF-AND-ON LOW-END GUSTS
THROUGH THIS AFTERNOON BUT WINDS SHOULD DIE OFF LATER THIS EVENING
AND OVERNIGHT TO GENERALLY 5KT OR BELOW EVERYWHERE.

OUTLOOK...EXPECTING GENERALLY DRY AND QUIET WEATHER THROUGH THE
WEEKEND WITH A GRADUAL INCREASE IN CHANCES FOR SHOWERS/THUNDERSTORMS
AND RESTRICTIONS FOR THE START OF THE NEW WORK WEEK.

CONFIDENCE TABLE...

            20-02Z        02-08Z        08-14Z        14-18Z
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...TDP


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