798  
FXUS62 KGSP 232353  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
653 PM EST SAT FEB 23 2019  
   
SYNOPSIS
 
 
THE WET PATTERN WILL CONTINUE THROUGH TONIGHT BEFORE A ROBUST  
COLD FRONT FINALLY MOVES THROUGH THE REGION LATE TONIGHT THROUGH  
SUNDAY MORNING. THE EARLY PART OF THE WEEK SHOULD BE DOMINATED  
BY DRY HIGH PRESSURE. A COLD FRONT MAY MOVE THROUGH THE REGION FROM  
THE NORTHWEST ON WEDNESDAY, BUT MOISTURE WITH THIS FRONT REMAINS  
HIGHLY UNCERTAIN. BETTER MOISTURE COULD ARRIVE TOWARD NEXT WEEKEND.  
 

 
   
NEAR TERM /THROUGH SUNDAY/
 
 
630 PM UPDATE...ADJUSTED BROAD AREAS OF COOLER THAN FCST/D TEMPS AND  
TD/S. WEDGE IS HOLDING STRONG AND GOOD MOISTURE ADV WILL KEEP LOW  
CLOUDS AND OCCASIONAL LOWER VSBY OVER THE FA THIS EVENING. PRECIP  
HAS DROPPED OFF AND LOWERED POPS A BIT UNTIL UPSLOPE ENHANCED  
PRE/FRONTAL -SHRA BEGINS ACROSS THE WRN NC MTNS LATER THIS EVENING.  
 
AS OF 250 PM: WITH NOT MUCH OF A CHANGE FROM YESTERDAY, IT'S BEEN  
QUITE THE DREARY LAST SATURDAY OF FEBRUARY, WITH EXPANSIVE CLOUD  
COVER, ISOLATED TO SCATTERED SHOWERS/DRIZZLE, AND BELOW NORMAL  
TEMPERATURES. THIS ALL A RESULT OF THE CAD SET UP IN PLACE ACROSS  
THE CAROLINAS (AND UPGLIDE OVER THIS FEATURE), WITH SFC HIGH  
PRESSURE OFF TO THE NORTHEAST, AND UPPER RIDGING IN PLACE. THOUGH  
LATEST RADAR IMAGERY CONTINUES TO DEPICT A LULL IN PRECIPITATION  
ACROSS THE FA THIS AFTERNOON, WITH THE HEAVIER RAINFALL CURRENTLY  
ACROSS MUCH OF TN INTO VA, DO EXPECT RAINFALL COVERAGE TO PICK UP  
TONIGHT AS A STRONG COLD FRONT PUSHES THROUGH THE AREA OVERNIGHT  
INTO SUNDAY MORNING, WITH IT'S PARENT SFC LOW EJECTING FROM THE  
CENTRAL PLAINS INTO THE UPPER MIDWEST. WITH ANOTHER ROUND OF HEAVY  
RAINFALL (THOUGH QPF AMOUNTS REMAIN AT OR BELOW 0.50"), ALREADY  
SATURATED SOILS FROM THE PAST FEW DAYS, AND AREA RIVERS AND STREAMS  
ALREADY NEARING THEIR BANKS, WITH SOME ALREADY IN MINOR FLOOD STAGE,  
A FLOOD WATCH REMAINS IN EFFECT FOR PORTIONS OF THE FA THROUGH INTO  
SUNDAY. WITH THE WEDGE SLOW TO RETREAT, EXPECT OVERNIGHT LOW  
TEMPERATURES IN THE MID TO UPPER 40S ACROSS THE SOUTHERN MOUNTAINS,  
NORTHEAST GA, AND MOST OF THE UPSTATE, COOLER INTO THE LOWER 40S  
ACROSS THE NW PIEDMONT.  
 
BEHIND THE COLD FRONT, CONDITIONS WILL DRY QUICKLY WITH THE RETURN  
OF NW FLOW, WITH CLEARING SKIES INTO LATE MORNING/EARLY AFTERNOON ON  
SUNDAY. WITH THE PROJECTED TIGHTENING PRESSURE GRADIENT PER LATEST  
GUIDANCE, A WIND ADVISORY AS WELL AS A HIGH WIND WARNING ARE IN  
EFFECT FOR PORTIONS OF WESTERN NC, WITH A WIND ADVISORY BEGINNING AS  
EARLY AS TONIGHT FOR THE HIGHER ELEVATIONS AHEAD OF THE APPROACHING  
COLD FRONT, EXPANDING TO ALL ACROSS ACROSS THE NC MOUNTAINS ON  
SUNDAY. PLEASE SEE CURRENT PRODUCTS FOR ADDITIONAL INFORMATION.  
ELSEWHERE, ACROSS THE UPSTATE AND NW PIEDMONT, EXPECT GUSTY WINDS  
THROUGHOUT THE DAY. THOUGH WINDS ARE EXPECTED TO REMAIN BELOW  
ADVISORY CRITERIA, WITH SATURATED SOILS, WOULD NOT ENTIRELY RULE OUT  
THE POTENTIAL FOR A FEW WEAK DOWNED TREES. HIGH TEMPERATURES ON  
SUNDAY WILL REBOUND TO ABOVE NORMAL.  
 

 
   
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/
 
 
AS OF 1248 PM EST SATURDAY: AFTER THE WEEK WE'VE HAD, THE FIRST  
PART OF NEXT WEEK WILL BE A WELCOME BREAK. THE ONLY ISSUE WILL BE  
THE WIND, WHICH STILL LOOKS VERY STRONG ACROSS THE RIDGETOPS AND  
PEAKS OF THE NORTHERN MOUNTAINS OF NC, BUT PROBABLY NOT A PROBLEM  
OUTSIDE THE MTNS. FCST SOUNDINGS SHOW THE BOUNDARY LAYER DECOUPLING  
SUNDAY EVENING ACROSS THE FOOTHILLS, SO WE LOSE THE DEEPER MIXING  
THAT WOULD ALLOW THE STRONGER WINDS TO REACH THE GROUND. BY THE  
TIME WE WARM UP ON MONDAY MORNING, THE STRONG WINDS WILL BE PULLING  
OUT TO THE NORTH. THE REST OF THE FORECAST WILL BE FAIR AND DRY,  
COURTESY OF A NEARLY-ZONAL UPPER PATTERN THAT SUPPORTS HIGH PRESSURE  
RIDGING DOWN FROM THE NW ON MONDAY AND THEN MOVING BY TO THE NORTH  
ON TUESDAY. TEMPS SHOULD BE ABOUT A CATEGORY ABOVE NORMAL WITH A  
SLIGHT WARMING TREND FROM MONDAY INTO TUESDAY.  
 

 
   
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
 
 
AS OF 204 PM EST SATURDAY: STILL NOT A LOT OF CONFIDENCE IN THE  
FORECAST FOR THE LATTER HALF OF THE WEEK, AS THERE ISN'T MUCH OF A  
COHERENT SIGNAL IN THE MODEL GUIDANCE AND CONSISTENCY/CONSENSUS  
ARE FAIRLY POOR, ALTHO IT ACTUALLY IMPROVES AS WE HEAD INTO  
NEXT WEEKEND. THE UPPER FLOW PATTERN STAYS RELATIVELY FLAT FOR  
WEDNESDAY AND THURSDAY, THEN STARTS TO BUCKLE INTO FRIDAY AS AN  
UPPER LOW MOVES DOWN FROM CANADA INTO THE NRN PLAINS AND A RIDGE  
STARTS TO BUILD OFF THE EAST COAST AND OVER THE NEW ENGLAND STATES  
IN RESPONSE. PERIODIC WEAK BITS OF MID/UPPER FORCING WILL PASS  
ACROSS THE SOUTHEAST STATES DURING THIS TIME, ALONG WITH A LIGHT  
EASTERLY FLOW AT LOW LEVELS, BUT NO REAL COLD AIR DAMMING SIGNAL  
IS INDICATED UNTIL FRIDAY. THIS FAVORS KEEPING A LOW PRECIP PROB  
EACH DAY WITH TEMPS CLOSE TO NORMAL, BUT WARM ENOUGH OVERNIGHT  
TO KEEP ALL THE LIGHT PRECIP AS RAIN. ONCE WE GET INTO FRIDAY AND  
BEYOND, CONFIDENCE ACTUALLY GOES ON AN UPWARD TREND. BOTH MODELS  
HAVE THE SAME IDEA...THAT BEING A WEAK COASTAL LOW DEVELOPING  
ON FRIDAY WITH A COLD AIR DAMMING WEDGE EAST OF THE BLUE RIDGE,  
AND THE NEXT LOW PRESSURE SYSTEM ORGANIZING OVER THE PLAINS. WE  
SEE REMARKABLY GOOD AGREEMENT WITH BRINGING ANOTHER STRONG COLD  
FRONT EASTWARD FRIDAY NIGHT AND THEN MOVING IT ACROSS THE REGION  
ON SATURDAY, BUT WE LIMIT OUR PRECIP PROB TO THE CHANCE RANGE FOR  
THE TIME BEING AS THIS IS THE NEW DAY 7 AND THE TIMING COULD EASILY  
SLIP. FORTUNATELY, TEMPS WILL REMAIN TOO WARM FOR ANY PRECIP-TYPE  
ISSUES EXCEPT AT THE HIGHEST PEAKS OVER NEXT WEEKEND.  
 

 
   
AVIATION /00Z SUNDAY THROUGH THURSDAY/
 
 
AT KCLT AND ELSEWHERE: A STG SFC WEDGE WILL REMAIN PLACE ACROSS THE  
AREA WHILE VERY LOW CIGS IN GOOD MOISTURE ADV CONTINUES THRU THE  
OVERNIGHT. CIGS WILL REMAIN IN THE IFR RANGE WITH SOME TEMPORARY  
MVFR OVER THE UPSTATE SC SITES POSSIBLE. VSBY WILL BE TRICKY AS  
PERIODS OF -SHRA HAVE BEEN SCOURING OUT THE LLVLS. VFR VSBY  
CURRENTLY OVER THE KCLT, KAVL, KAND, AND KGSP TERMINALS...BUT A  
GENERAL DECREASE INTO MVFR OR IFR THRU THE OVERNIGHT IS EXPECTED AND  
WILL ADDRESS WITH TEMPOS A STG COLD FRONT PUSHES IN FROM THE WEST  
TONIGHT AND HAVE TIMED LLWS ACROSS ALL SITES BEG AFT 04Z ACROSS  
THE MTNS AND ARND 06Z AT KCLT. SKIES WILL CLEAR UP RATHER QUICKLY  
ARND NOON TO VFR CONDS...WITH MODERATE NW/LY TO SW/LY GUSTS  
DEVELOPING AND CONTINUING THRU THE PERIOD.  
 
OUTLOOK: EXPECT VFR TO PREVAIL THROUGH THE MIDDLE OF NEXT WEEK.  
 
CONFIDENCE TABLE...  
 
00-06Z 06-12Z 12-18Z 18-00Z  
KCLT HIGH 89% MED 76% MED 78% HIGH 100%  
KGSP HIGH 84% MED 77% MED 75% HIGH 100%  
KAVL MED 78% HIGH 87% HIGH 97% HIGH 100%  
KHKY HIGH 85% HIGH 85% HIGH 81% HIGH 100%  
KGMU HIGH 81% MED 65% MED 71% HIGH 100%  
KAND MED 70% MED 71% HIGH 90% 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:  
 
WWW.WEATHER.GOV/GSP/AVIATION  
 

 
   
GSP WATCHES/WARNINGS/ADVISORIES
 
 
GA...FLOOD WATCH THROUGH SUNDAY MORNING FOR GAZ010-017-018-026-028.  
NC...HIGH WIND WARNING FROM 7 AM SUNDAY TO 7 AM EST MONDAY FOR  
NCZ033-049-050-501-503-505.  
FLOOD WATCH THROUGH SUNDAY MORNING FOR NCZ033-035>037-048>053-  
056>059-062>065-068>072-501>510.  
WIND ADVISORY UNTIL 7 PM EST SUNDAY FOR NCZ048-051-052-058-059-  
062>064.  
WIND ADVISORY FROM 7 AM TO 7 PM EST SUNDAY FOR NCZ053-065.  
WIND ADVISORY UNTIL 7 AM EST SUNDAY FOR NCZ033-049-050.  
SC...FLOOD WATCH THROUGH SUNDAY MORNING FOR SCZ001>010.  
 

 
 

 
SYNOPSIS...DEO  
NEAR TERM...SBK/SGL  
SHORT TERM...PM  
LONG TERM...PM  
AVIATION...SBK  
 
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