547  
FXUS62 KGSP 070256  
AFDGSP  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC  
956 PM EST SAT FEB 6 2016  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL REMAIN ACROSS THE FORECAST AREA THROUGH THE  
WEEKEND...WHILE STRONG LOW PRESSURE FORMS OFF THE CAROLINA COAST. A  
COLD FRONT WILL PUSH THROUGH THE REGION ON MONDAY...USHERING IN  
BELOW NORMAL TEMPERATURES AND AN INCREASE OF MOISTURE INTO THE  
MIDDLE OF NEXT WEEK.  
 

 
   
NEAR TERM /THROUGH SUNDAY/
 
 
AS OF 945 PM EST...REPORTS ARE COMING IN OF BRIEF SLEET AND SNOW  
FLURRIES IN A FEW LOCATIONS ALONG INTERSTATE 85 FROM SPARTANBURG TO  
SALISBURY. THIS MAY CONTINUE THROUGH LATE EVENING AS RADAR SHOWS  
WEAK 20 TO 25 DBZ RETURNS FALLING FROM 8000 FT CLOUD BASES...AND  
SCATTERED FLURRIES HAVE BEEN ADDED TO THE FORECAST IN AFFECTED AREAS.  
 
OTHERWISE...THE FORECAST REMAINS ON TRACK WITH THE POTENT CLOSED  
UPPER LOW MOVING EAST TOWARD THE AL/GA BORDER LATE THIS  
EVENING...AND ASSOCIATED RAPID CYCLOGENESIS UNDERWAY OFF THE  
SOUTHEAST COASTLINE. DESPITE THE EVENING EXCITEMENT OF BRIEF FROZEN  
PRECIP FALLING FROM HIGH CLOUD BASES...THE MAIN AREA OF CONCERN FOR  
OUR FORECAST AREA CONTINUES TO BE LOCATIONS SOUTHEAST OF A CHESTER  
SC TO MONROE NC LINE. CONSIDERABLE UNCERTAINTY CONTINUES OVER WHERE  
ANY HEAVIER BANDING STRUCTURES MIGHT SET UP WEST OF THE OFFSHORE  
LOW...WITH EASTERN PIEDMONT AND COASTAL PLAIN SECTIONS OF THE  
CAROLINAS THE MOST LIKELY CANDIDATES. HOWEVER...DEEP LAYER  
FRONTOGENESIS COULD WELL WRAP SHOWERY ACTIVITY WESTWARD THROUGH THE  
PIEDMONT TO OVERLAP WITH THE INCREASINGLY COLD PROFILES NEAR THE  
INTERSTATE 77 CORRIDOR. THE LATEST RAP AND NAM WET BULB PROFILES  
NEAR CLT DEPICT SUBFREEZING TEMPERATURES IN ALL BUT THE VERY LOWEST  
FEW HUNDRED FEET OVERNIGHT...AND THIS WOULD SEEM TO SUPPORT SNOW  
VERSUS RAIN AS THE PRIMARY PTYPE WITH ANY SHOWERS REACHING WESTWARD  
INTO THE LOWER PIEDMONT. POPS HAVE BEEN PUSHED INTO THE LOW LIKELY  
RANGE FOR FAR SE UNION COUNTY NC AND A DUSTING OF SNOW WILL BE  
POSSIBLE ON GRASSY SURFACES THERE OVERNIGHT INTO SUNDAY MORNING.  
TEMPS WERE COOLED SLIGHTLY BASED ON OBSERVATIONAL  
TRENDS...DEVELOPING LOW LEVEL COLD ADVECTION...AND SOME  
EVAPORATIONAL COOLING IN SPOTS.  
 
ON SUNDAY...THE UPPER TROUGH REACHING THE COASTAL WATERS WILL  
FURTHER DEEPEN THE OFFSHORE SURFACE LOW THROUGH THE DAY. OUR REGION  
SHOULD REMAIN DRY BEHIND THE DEPARTING DEEPER MOISTURE...BUT GUSTY  
NORTHERLY WINDS MAY DEVELOP BEHIND THE SYSTEM...ESPECIALLY ACROSS  
THE EASTERN HALF OF THE FORECAST AREA. MAXIMUM TEMPERATURES SHOULD  
MAKE IT BACK TO AROUND NORMAL.  
 

 
   
SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/
 
 
AS OF 230 PM SATURDAY...A COLD FRONT WILL APPROACH THE SOUTHERN  
APPALACHIANS EARLY MONDAY MORNING. BY THE TIME THE FRONT  
ARRIVES...LOW TEMPERATURES ACROSS THE CWA ARE FORECAST TO RANGE FROM  
THE UPPER 20S ACROSS THE MTNS TO LOW TO MID 30S ACROSS THE UPPER  
SAVANNAH RIVER VALLEY. 12Z GFS360 INDICATES THAT A LARGE FIELD OF  
BROAD Q-VECTOR CONVERGENCE WILL SWEEP ACROSS THE WESTERN CAROLINAS  
AND NE GA ON MONDAY. THE COMBINATION OF THE SFC COLD FRONT AND  
PASSING MID LEVEL SYNOPTIC SCALE FORCING WILL SUPPORT PRECIP CHCS  
SPREADING ACROSS THE FOOTHILLS AND PIEDMONT DURING MONDAY AFTERNOON.  
BETWEEN 18Z MON TO 0Z TUES...H85 WINDS WILL SHIFT FROM THE NW AND  
INCREASE TO 25-30 KTS...SUPPORTING UPSLOPE FLOW ALONG THE TN BORDER.  
GIVEN THE SFC TEMPERATURES AND LOW LEVEL THERMAL PROFILES...PRECIP  
SHOULD FALL AS EITHER SNOW OR A COLD RAIN. SNOW IS EXPECTED ACROSS  
THE MTNS IN THE MORNING...THEN SHOULD MIX OVER TO RAIN WITHIN THE  
VALLEY FLOOR BY MID DAY. TEMPS ACROSS THE RIDGES SHOULD YIELD HIGH  
ELEVATION SNOWFALL THROUGH THE DAYLIGHT HOURS. AREAS EAST OF THE  
MTNS SHOULD SEE ONLY RAINFALL AS HIGH TEMPS WARM TO THE 40S ACROSS  
THE REGION.  
 
MODERATE TO STRONG H85 CAA WILL SWEEP ACROSS THE FORECAST AREA  
MONDAY NIGHT...WITH MTN LOCATIONS COOLING TO -12 TO -14 C BY 12Z  
TUES. MIN TEMPS ARE FORECAST TO RANGE FROM THE TEENS ACROSS THE MTNS  
TO LOW 20S WITHIN THE VALLEYS...UPPER 20S TO THE EAST. COLD H85  
TEMPS WILL REMAIN ACROSS THE MTNS THROUGH THE DAY...SUPPORTED BY  
THICK CLOUD COVER AND GUSTY NW WINDS. CATE TO LIKELY POPS WILL  
REMAIN ACROSS THE TN BORDER COUNTIES THROUGH THE MORNING...REDUCING  
TO CHC POPS DURING THE AFTERNOON. FOOTHILL TO PIEDMONT AREAS WILL  
REMAIN GENERALLY DRY. HIGH TEMPS SHOULD REMAIN BELOW FREEZING ACROSS  
THE MTNS TO AROUND 40 EAST. MON AND TUES...TOTAL SNOWFALL FORECAST  
GIVES 2 TO 4 INCHES ALONG THE SPINE OF THE APPALACHIANS TO 1-2  
INCHES ACROSS THE VALLEYS OF THE TN BORDER COUNTIES. LITTLE TO NO  
ACCUMS EXPECTED ACROSS THE FOOTHILLS.  
 

 
   
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/
 
 
AS OF 200 PM SATURDAY...ONE MORE PIECE OF CHANNELED VORTICITY WILL  
DIVE THRU THE EASTERN CONUS TROF TUESDAY NIGHT...ENHANCING QG  
FORCING ACROSS THE SOUTHERN APPALACHIANS. FROM WEDNESDAY THRU  
THURSDAY NIGHT...THE EASTERN TROF WILL LIFT OUT SOMEWHAT...RESULTING  
IN MORE ZONAL FLOW ATOP THE CWFA. THEN ANOTHER CLIPPER SHORT WAVE  
SYSTEM WILL DIVE INTO THE MIDWEST ON FRIDAY...AND CARVE OUT THE  
EASTERN TROF AGAIN BY SATURDAY.  
 
AT THE SFC...A LARGE LOW PRESSURE SYSTEM WILL BE GRADUALLY FILLING  
OVER THE NORTHEAST...KEEPING OUR AREA UNDER PERSISTENT LLVL NWLY  
FLOW. MOISTURE WILL CONTINUE TO BANK UP ALONG THE USUAL NW FLOW  
UPSLOPE AREAS...BUT SHUD GRADUALLY TAPER OFF WEDNESDAY INTO  
WEDNESDAY NIGHT. ADDITIONAL SCATTERED TO OCCASIONALLY NUMEROUS SNOW  
SHOWERS ARE EXPECTED ALONG THE TN LINE...ESPECIALLY TUESDAY NIGHT  
THRU WEDNESDAY AFTERNOON. THE REST OF THE AREA SHUD BE MOSTLY CLEAR  
AND QUITE CHILLY. THICKNESSES AND 850 MB TEMPS BOTTOM OUT EARLY  
WEDNESDAY...WITH STILL SOME CAA AND WINDS TO MAKE FOR SOME WIND  
CHILL CONCERNS IN THE HIGH TERRAIN. ADDITIONAL SNOW ACCUMS SHUD BE  
GENERALLY LIGHT...BUT SOME SORT OF WINTER WX OR WIND CHILL ADV WILL  
LIKELY BE NEEDED UNTIL THINGS WIND DOWN. A REINFORCING COLD FRONT IS  
EXPECTED TO ACCOMPANY THE NEXT SYSTEM...BUT THE MEDIUM RANGE MODELS  
ARE IN DISAGREEMENT ON THE EXACT TIMING AND ON THE AMOUNT OF  
MOISTURE WITH IT. FOR NOW...I WILL INTRODUCE A SLGT CHC OF SNOW  
SHOWERS ALONG THE TN LINE FRIDAY THRU FRIDAY NIGHT. TEMPS WILL BE  
ABOUT 15-20 DEGREES BELOW NORMAL ON WEDNESDAY...WITH WIND CHILLS  
BELOW ZERO ABOVE ABOUT 3500 FT EARLY THURSDAY MORNING. THEN TEMPS  
WILL MODERATE BACK TO ONLY A CATEGORY OR TWO BELOW NORMAL BY  
FRIDAY...BEFORE THE NEXT SURGE OF COLD AIR BRINGING TEMPS BACK DOWN  
5 TO 10 DEG BELOW NORMAL FOR SATURDAY.  
 

 
   
AVIATION /03Z SUNDAY THROUGH THURSDAY/
 
 
AT KCLT....A SOLID SHIELD OF LOWERING VFR CLOUDS WILL REMAIN OVER  
THE AIRFIELD OVERNIGHT AS A STRONG UPPER LOW MOVES BY TO THE SOUTH.  
THIS SYSTEM...AND THE ASSOCIATED STRONG CYCLOGENESIS OFFSHORE...WILL  
CREATE SHOWER BANDS OVER THE COASTAL PLAIN AND CENTRAL PIEDMONT OF  
THE CAROLINAS...WHICH COULD FLIRT WITH THE KCLT AIRFIELD FROM THE  
SOUTHEAST OVERNIGHT. IN FACT...A BRIEF SNOW FLURRY IS POSSIBLE AT  
JUST ABOUT ANY TIME GOING FORWARD. THE CURRENT EXPECTATION IS THAT  
ANY SNOW SHOWER BANDS WILL REMAIN PRIMARILY SOUTHEAST OF A CHESTER  
TO MONROE LINE AND NOT IMPACT THE AIRFIELD...BUT THIS WILL NEED  
CLOSE MONITORING OVERNIGHT. OTHERWISE...NORTHERLY WINDS WILL  
INCREASE AND BECOME GUSTY THROUGH SUNDAY. VFR CIGS WILL SCATTER FROM  
THE WEST THROUGH LATE SUNDAY MORNING.  
 
ELSEWHERE...VFR CONDITIONS WILL CONTINUE THROUGH THE PERIOD...WITH  
LOWER ALTOCUMULUS CEILINGS FOR MOST OF THE EVENING HOURS AND EARLY  
OVERNIGHT...SCATTERING FROM THE WEST THROUGH THE REST OF SUNDAY  
MORNING. BREEZY NORTHERLY WINDS WILL PRODUCE SOME LOW END GUSTS AS  
THE PASSING UPPER LOW GENERATES A DEEP LOW PRESSURE SYSTEM OFF THE  
SOUTHEAST COAST. GUSTS INTO THE 20S WILL BE POSSIBLE AT KAVL...WITH  
GUSTS 15 TO 20 KT FROM KHKY TO KGMU.  
 
OUTLOOK...WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION ON SUNDAY  
NIGHT...BUT WITH SEVERAL ROUNDS OF STRONG UPPER LEVEL  
DISTURBANCES...MOISTURE...AND REINFORCING COLDER AIR ARRIVING FROM  
THE NORTHWEST MONDAY THROUGH WEDNESDAY. RESTRICTIONS WILL BE  
POSSIBLE...ESPECIALLY IN THE MOUNTAINS...WHERE SNOW SHOWERS ARE MOST  
LIKELY.  
 
CONFIDENCE TABLE...  
 
03-09Z 09-15Z 15-21Z 21-00Z  
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 SCHEDULE TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLET 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...NONE.  
NC...NONE.  
SC...NONE.  
 

 
 

 
SYNOPSIS...SBK  
NEAR TERM...HG  
SHORT TERM...NED  
LONG TERM...ARK  
AVIATION...HG  
 
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