769  
FXUS62 KCHS 032330  
AFDCHS  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE CHARLESTON SC  
630 PM EST FRI DEC 3 2021  
   
SYNOPSIS
 
 
HIGH PRESSURE WILL PREVAIL THROUGH MONDAY. A COLD FRONT WILL  
PUSH OFFSHORE MONDAY NIGHT THEN RETURN TO THE NORTH LATER IN  
THE WEEK AS LOW PRESSURE TRACKS WELL TO THE WEST BRINGING  
UNSETTLED CONDITIONS TO THE REGION.  
 

 
   
NEAR TERM /UNTIL 6 AM SATURDAY MORNING/
 
 
EARLY THIS EVENING: NO SIGNIFICANT CHANGES NEEDED TO THE  
FORECAST THROUGH SUNRISE. SATELLITE IMAGERY SHOWS SCATTERED  
CIRRUS CONTINUING TO SPREAD ACROSS THE AREA. HIGH PRESSURE WILL  
BE CENTERED SOUTH OF THE FORECAST AREA ACROSS THE EASTERN GULF  
OF MEXICO AND THE FLORIDA PENINSULA THROUGH THE NIGHT. THIS  
SETUP WILL DRIVE LIGHT SOUTHWEST TO WESTERLY FLOW ACROSS THE  
AREA. SCATTERED CIRRUS SHOULD BE PRESENT THROUGH THE NIGHT BASED  
ON UPSTREAM SATELLITE TRENDS. LOWS MOSTLY IN THE UPPER 40S TO  
LOW 50S STILL LOOK TO BE ON TRACK. THERE COULD BE SOME PATCHY  
FOG, MAINLY ACROSS PORTIONS OF SOUTHEAST SOUTH CAROLINA, BUT IT  
SHOULD MOSTLY BE SHALLOW WITH NO SIGNIFICANT VISIBILITY  
REDUCTION.  
 

 
   
SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/
 
 
QUIET CONDITIONS WILL PREVAIL AS WEAK HIGH PRESSURE HOLDS ITS  
INFLUENCE ON THE REGION. A WEAK BACKDOOR COLD FRONT WILL ATTEMPT  
TO DROP INTO SOUTH CAROLINA LATE SATURDAY NIGHT INTO SUNDAY  
MORNING, BUT SHOULD REMAIN TO THE NORTH AS THE PARENT  
ANTICYCLONE OVER THE MID-ATLANTIC LOOKS TO REMAIN TOO  
PROGRESSIVE IN THE ABSENCE OF SIGNIFICANT DIABATIC COOLING TO  
WEDGE THE FRONT THIS FAR SOUTH. INCREASING MOISTURE COUPLED WITH  
WEAK CONVERGENCE ALONG THE WEST WALL OF THE GULF STREAM COULD  
SPARK A FEW SHOWERS WELL OFFSHORE, BUT THIS ACTIVITY SHOULD  
REMAIN AWAY FROM LAND. A WARM, SOUTHWESTERLY WITH H8  
TEMPERATURES >11C WILL KEEP SURFACE TEMPERATURES IN THE ABOVE  
NORMAL CATEGORY WITH COASTAL TEMPERATURES BEING AUGMENTED BY SEA  
BREEZE CIRCULATIONS/ONSHORE FLOW EACH AFTERNOON. HIGHS WILL  
WARM INTO THE MID 70S EACH DAY EXCEPT POSSIBLY LIMITED TO THE  
LOWER 70S ACROSS SOUTHERN SOUTH CAROLINA SUNDAY AFTERNOON DUE TO  
THE PROXIMITY OF THE BACKDOOR FRONT. LOWS WILL DROP INTO THE  
MID-UPPER 40S INLAND TO UPPER 50S BEACHES SUNDAY MORNING WITH  
LOWER 50S INLAND TO NEAR 60 BEACHES MONDAY MORNING.  
 

 
   
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
 
 
A STRONG COLD FRONT WILL APPROACH THE SOUTHEAST U.S. MONDAY AS  
NORTHERN STREAM SHORTWAVE DIGS ACROSS THE NORTHERN PLAINS INTO  
GREAT LAKES REGION. THE FRONT IS ON TARGET PUSH THROUGH THE AREA  
MONDAY NIGHT BEFORE STALLING TUESDAY AS THE SUPPORTING  
SHORTWAVE SHEARS OUT ACROSS SOUTHERN QUEBEC. ALTHOUGH BOTH  
SURFACE DEWPOINTS AND PWATS AND INCREASE AHEAD OF THE FRONT, THE  
DEPTH OF THE MOISTURE DOES NOT LOOK OVERLY IMPRESSIVE WITH MEAN  
RH IN THE 850-700 HPA LAYER ONLY RUNNING 50-65%. THIS IS  
USUALLY TOO DRY TO SUPPORT MUCH IN THE WAY OF MEANINGFUL  
RAINFALL. WITH THE LACK OF STRONG/DEEP QUASI- GEOGRAPHIC FORCING  
CORRIDORS NOTED IN THE VARIOUS MODEL TIME HEIGHTS, THE RISK FOR  
ANY MEASURABLE RAINFALL LOOKS LIMITED ESPECIALLY GIVEN THE  
MARGINAL MOISTURE PROFILES. THE STATIONARY FRONT WILL QUICKLY  
RETURN TO THE NORTH TUESDAY NIGHT INTO WEDNESDAY AS DIGGING  
SHORTWAVE ENERGY OVER THE SOUTHERN PLAINS INITIATES CYCLOGENESIS  
OVER THE TEXAS PANHANDLE. THIS LOW IS FORECAST TO PROPAGATE  
QUICKLY TO EAST/NORTHEAST AND REFORM OVER THE MID-ATLANTIC WHILE  
DRIVING YET ANOTHER FRONT INTO THE AREA BY MID-LATE WEEK. THERE  
REMAINS MUCH UNCERTAINTY ON THE TIMING AND POSITION OF THIS  
FRONT NEXT WEEK, BUT SIGNALS ARE THERE THAT RAIN CHANCES WILL  
INCREASE ACROSS THE SOUTHEAST SOUTH CAROLINA AND SOUTHEAST  
GEORGIA.  
 

 
   
AVIATION /00Z SATURDAY THROUGH WEDNESDAY/
 
 
VFR CONDITIONS WILL PREVAIL AT KCHS, KJZI, AND KSAV THROUGH 00Z  
SUNDAY.  
 
EXTENDED AVIATION OUTLOOK: THERE ARE NO CONCERNS AT THIS TIME.  
RAIN WITH A COLD FRONT WEDNESDAY COULD BRING REDUCTIONS IN VSBYS  
AND CIGS.  
 

 
   
MARINE
 
 
TONIGHT: HIGH PRESSURE WILL PREVAIL, LEADING TO A RATHER  
RELAXED PRESSURE GRADIENT ACROSS LOCAL WATERS. IN GENERAL,  
CONDITIONS WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY CRITERIA  
WITH A SOUTH-SOUTHWEST WIND BETWEEN 5-10 KT. SEAS WILL RANGE  
BETWEEN 1-2 FT.  
 
SATURDAY THROUGH WEDNESDAY: THERE ARE NO CONCERNS AT THIS TIME.  
SOUTH TO SOUTHWEST WINDS WILL PREVAIL FOR MUCH OF THE PERIOD,  
EXCEPT FOR TUESDAY WHEN WINDS TURN NORTHEAST BEHIND A COLD  
FRONT. THESE NORTHEAST WINDS WILL QUICKLY RETURN MORE SOUTHERLY  
BY WEDNESDAY AS THE FRONT LIFTS BACK TO THE NORTH. BOTH WINDS  
AND SEAS LOOK TO REMAIN BELOW SMALL CRAFT ADVISORY THRESHOLDS.  
 

 
   
TIDES/COASTAL FLOODING
 
 
PERIGEAN SPRING TIDES ARE EXPECTED INTO EARLY NEXT WEEK DUE TO  
INFLUENCES FROM THE NEW MOON AND LUNAR PERIGEE. WHILE THE WIND SET-  
UP WILL NOT SUPPORT SIGNIFICANT TIDAL DEPARTURES, MINOR COASTAL  
FLOODING IS POSSIBLE DURING THE MORNING HIGH TIDES SATURDAY AND  
SUNDAY, POSSIBLY EXTENDING INTO MONDAY. COASTAL FLOODING WILL BE  
CONFINED TO COASTAL PORTIONS OF CHARLESTON AND COLLETON COUNTIES.  
COASTAL FLOOD ADVISORIES COULD BE NEEDED.  
 

 
   
CHS WATCHES/WARNINGS/ADVISORIES
 
 
GA...NONE.  
SC...NONE.  
MARINE...NONE.  
 

 
 

 
 
NEAR TERM...BSH  
SHORT TERM...  
LONG TERM...  
AVIATION...BSH  
MARINE...DPB  
TIDES/COASTAL FLOODING...  
 
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