« Back
NWS Peachtree City, Ga » Text Product » CHS Area Forecast Discussion


Printer-friendly Version
Current Version              Previous Versions:   1  2  3  4  5  6  7  8  9  

Area Forecast Discussion

581
FXUS62 KCHS 041224
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
724 AM EST WED MAR 4 2015

.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL EXTEND ACROSS THE REGION TODAY. A
STRONG COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY AND
PASS OFF THE COAST EARLY THURSDAY EVENING. COLDER HIGH PRESSURE
WILL BUILD OVER THE AREA INTO SATURDAY...WITH A COASTAL TROUGH TO
DEVELOP OFFSHORE LATE IN THE WEEKEND. ANOTHER STORM SYSTEM COULD
IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOG HAS LIFTED OVER MOST AREAS THIS MORNING. THE ONLY EXCEPTION IS
ALLENDALE COUNTY WHERE WIDESPREAD DENSE FOG IS STILL BEING
REPORTED BY THE KAQX AWOS AND EMERGENCY MANAGEMENT OFFICIALS. THE
DENSE FOG ADVISORY HAS BEEN CANCELLED FOR HAMPTON-INLAND COLLETON-
DORCHESTER AND INLAND BERKELEY...BUT WAS EXTENDED UNTIL 9 AM FOR
ALLENDALE COUNTY.

THE LOWCOUNTRY AND COASTAL EMPIRE WILL EXPERIENCE WELL ABOVE
NORMAL TEMPERATURES TODAY AS THE AREA IS POSITIONED BETWEEN
ATLANTIC HIGH PRESSURE WELL OFFSHORE AND AN APPROACHING COLD FRONT
FROM THE NORTHWEST. MID-LEVEL WARM AIR ADVECTION PUSHING 850 HPA
TEMPERATURES TO 12C COUPLED WITH RISING 1000-850 HPA THICKNESSES
WILL SUPPORT HIGHS IN THE LOWER 80S AWAY FROM THE COAST WITH
VALUES LIKELY REMAINING JUST BELOW RECORD TERRITORY. TEMPERATURES
ACROSS THE COASTAL COUNTIES...ESPECIALLY THE SOUTH CAROLINA
COASTAL ZONES...WILL FALL DURING THE MID-LATE AFTERNOON HOURS A
ROBUST RESULTANT SEA BREEZE CIRCULATION PUSHES INLAND AND DRAGS
CONSIDERABLY COOLER MARITIME AIR AND POSSIBLY A LITTLE SEA FOG
INLAND WITH IT. HAVE TRIED TO ADJUST HOURLY TEMPERATURES TO
ACCOUNT FOR THIS.

IT WILL LIKELY BECOME A BIT BREEZY THIS AFTERNOON AS MIXING
HEIGHTS RISE AND TAP INTO THE BELT OF HIGHER WINDS ALOFT. COULD
SEE GUSTS OF 25-30 MPH AT TIMES AWAY FROM THE COAST. THE WATER
TEMPERATURES IN LAKE MOULTRIE ARE RUNNING IN THE MID-UPPER 40S.
THE RESULTING STRONG MARINE INVERSION SHOULD ELIMINATE SIGNIFICANT
MIXING OVER THE LAKE WATERS...EXCEPT MAYBE ALONG THE IMMEDIATE
LAKESHORE...BUT EVEN THERE THE LAKE BREEZE CIRCULATION SHOULD
STABILIZE THINGS BY EARLY AFTERNOON. THERE ARE NO PLANS TO ISSUE A
LAKE WIND ADVISORY ATTM.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
TONIGHT...IT WILL BE A WARM AND HUMID NIGHT ACROSS THE REGION. THE
ATMOSPHERE LOOKS TO REMAIN WELL MIXED WITH ANOTHER PRE-FRONTAL
LOW-LEVEL JET TRAVERSING THE REGION. DO NOT ANTICIPATE FOG TO BE A
SIGNIFICANT PROBLEM EARLY THURSDAY WITH BOUNDARY LAYER-975 HPA
WINDS HOLDING IN THE 15-30 KT RANGE. SOUTHWEST SURFACE TRAJECTORIES
SHOULD KEEP ANY SEA FOG OVER THE ATLANTIC...ALTHOUGH SOME MAY
BRUSH THE CHARLESTON COUNTY COAST GIVEN THE ORIENTATION OF THE
COAST THERE. LOWS WILL RANGE FROM THE LOWER 60S INLAND TO THE
UPPER 50S/NEAR 60 AT THE COAST.

THURSDAY...WILL LIKELY START OFF VERY MILD WITH WIDESPREAD LOW
CLOUDS THAT SHOULD ERODE PRIOR TO LATE MORNING MOST AREAS SETTING
THE STAGE FOR A WARM...OCCASIONALLY BREEZY AFTERNOON AHEAD OF
RAINS APPROACHING IN ADVANCE A COLD FRONT. WE BUMPED UP TEMPS JUST
A BIT MORE ON THIS MORNINGS PACKAGE TO SHOW MORE HIGHS TOUCHING 80
DEGREES AND EVEN A FEW LOWER 80S IN SE GEORGIA. DEW POINTS WILL BE
AT OR SLIGHTLY ABOVE 60 DEGREES THROUGH EARLY AFTERNOON. WE BACKED
OFF A BIT ON TIMING SHALLOW CONVECTIVE RAINS THROUGH THE FORECAST
AREA FROM MID AFTERNOON WEST TO CLOSER TO LATE IN THE AFTERNOON
ALONG THE COAST. INSTABILITY IS VERY WEAK WITH POOR LAPSE RATES
AND MUCAPES BELOW 500 J/KG DESPITE THE WARM TEMPS AND ELEVATED
SURFACE DEW POINTS. WE HAVE A SHORT WINDOW FOR AN ISOLATED TSTMS
BUT NOT LOOKING FOR ANY SIGNIFICANT CONVECTION RISK.

THURSDAY NIGHT...THE STRONG COLD FRONT ACCOMPANIED BY IMPRESSIVE
COLD AIR ADVECTION WILL MOVE WELL OFFSHORE FRIDAY NIGHT AND
SHOWERS WILL DECREASE FROM WEST TO EAST OVERNIGHT. TEMPS WILL
BEGIN A FREE-FALL INTO THE 30S ACROSS NORTHERN ZONES TOWARD
DAYBREAK WITH READINGS FALLING INTO THE 40S ACROSS SE GEORGIA.

FRIDAY...FRIDAY LOOKS LIKE AN INTERESTING DAY AS MODELS IN
GENERAL AGREEMENT ON DEVELOPING A SECONDARY AREA OF RAINS ACROSS
THE FORECAST AREA AS A MID LEVEL SHORT WAVE MOVES INTO THE SE
STATES. THERE LOOKS TO BE GOOD UPPER FORCING FOR ASCENT AND THE
BIG QUESTION WILL BE SURFACE TEMPS AS THE SHALLOW AND COLD CP AIR
MASS BECOMES ENTRENCHED. NAM/GFS SOUNDINGS LOOK VERY COLD AND WE
WILL HAVE TO WATCH FOR SOME FREEZING RAIN POTENTIAL ACROSS OUR
NORTHERN SOUTH CAROLINA ZONES. SURFACE WET BULB TEMPS ARE PROGGED
TO BE NEAR OR JUST BELOW FREEZING OVER INTERIOR PORTIONS OF
SOUTHEAST SC SO WILL HAVE TO WATCH THIS CAREFULLY OVER THE NEXT 24
HOURS. OTHERWISE...IT APPEARS TO BE A VERY COLD RAIN WITH TEMPS IN
THE UPPER 30S TO LOWER 40S COMING ON THE HEELS OF AN 80 DEGREE
DAY.

SATURDAY...HIGH PRES THEN THEN BUILD OVER THE REGION THROUGH
SATURDAY. CLEARING AND COLD FRIDAY NIGHT WITH A POTENTIAL FREEZE
OR FROST ISSUE ALONG AND NORTH OF I-16. A GOOD BIT OF SUNSHINE AND
DRY WEATHER IS LIKELY ON SATURDAY WITH HIGHS WELL BELOW CLIMO...IN
THE 50S MOST AREAS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
THERE REMAINS A GOOD BIT OF UNCERTAINTY IN THE LONG TERM PERIOD
AS AN ACTIVE BAROCLINIC ZONE IS EXPECTED TO WAVER FROM THE
NORTHERN GULF COAST REGION AND FLORIDA LATE IN THE WEEKEND TO
GEORGIA AND THE CAROLINAS DURING EARLY TO MID WEEK. GLOBAL MODELS
DIFFER ON TIMING AND STRENGTH OF THESE IMPULSES MOVING THROUGH THE
SE STATES DURING THIS TIME. WITH PERIODS OF CLOUDS AND SHOWERS
POSSIBLE FROM TIME TO TIME...TEMPS WILL PROBABLY BE NEAR OR
SLIGHTLY BELOW CLIMO.

&&

.AVIATION /13Z WEDNESDAY THROUGH SUNDAY/...
FOG AND LOW CLOUDS HAVE MIXED OUT. EXPECT VFR TO PERSIST FOR THE
NEXT 24 HOURS. LOW-LEVEL WIND SHEAR /LLWS/ WILL BE AN ISSUE
THROUGH ABOUT 14Z OR UNTIL WINDS BEGIN TO GUST. CONDITIONS WILL
FAVOR LLWS AGAIN TONIGHT AFTER 01Z AS ANOTHER NOCTURNAL JET
STRENGTHENS. GUSTY WINDS LIKELY BOTH TERMINALS TODAY WITH GUSTS IN
EXCESS OF 20 KT. LOW PROBABILITIES FOR LOW CLOUDS 06-12Z
THURSDAY...BUT CONFIDENCE IS NOT HIGH ENOUGH ATTM TO INCLUDE A
MENTION.

EXTENDED AVIATION OUTLOOK...FLIGHT RESTRICTIONS IN LOW CLOUDS
PROBABLE THURSDAY MORNING THEN VFR FOR A PERIOD PRIOR TO A STRONG
COLD FRONT LATE IN THE DAY THURSDAY. ADDITIONAL FLIGHT RESTRICTIONS
POSSIBLE THURSDAY NIGHT INTO FRIDAY ALONG WITH GUSTY N TO NE SURFACE
WINDS. CONDITIONS EXPECTED TO IMPROVE OVER THE WEEKEND WITH HIGH
PRES AND VFR.

&&

.MARINE...
CANCELLED MARINE DENSE FOG ADVISORY FOR CHARLESTON HARBOR AS
CONDITIONS THERE HAVE IMPROVED SIGNIFICANTLY.

TODAY...WIDESPREAD DENSE SEA FOG WILL PERSIST ACROSS THE COASTAL
WATERS THIS MORNING AND LIKELY REMAINING IN PLACE THROUGH THE
AFTERNOON HOURS. THE FOG MAY MIX OUT JUST ENOUGH TO BRING VSBYS
ABOVE 1 NM BY EARLY AFTERNOON...SO WILL MAINTAIN A 2 PM EXPIRATION
TIME FOR THE MARINE DENSE FOG ADVISORY...EXCEPT NOON IN THE
CHARLESTON HARBOR AND THE GEORGIA OFFSHORE WATERS. IT IS VERY
POSSIBLE THE ADVISORY MAY NEED TO EXTENDED BEYOND 2 PM. OTHERWISE...
EXPECT SOUTH TO SOUTHEAST WINDS AROUND 15 KT TO PREVAIL. IT COULD
GET RATHER GUSTY IN THE CHARLESTON HARBOR FOR A FEW HOURS THIS
AFTERNOON AS THE RESULTANT SEA BREEZE MOVES INLAND...BUT WILL HOLD
GUSTS TO 20 KT FOR NOW...BUT A SMALL CRAFT ADVISORY CAN NOT BE
COMPLETELY RULED OUT.

TONIGHT...SEA FOG WILL PERSIST THROUGH THE NIGHT...ESPECIALLY OVER
THE SOUTH CAROLINA WATERS WHERE SOUTHWEST TRAJECTORIES WILL FAVOR
LONGER PARCEL RESIDENCE TIMES OVER THE COLD SHELF WATERS. ANOTHER
MARINE DENSE FOG ADVISORY MAY BE NEEDED. WINDS WILL GENERALLY
REMAIN AROUND 15 KT WITH SEA BUILDING 2-4 FT NEARSHORE...EXCEPT
3-5 FT OVER THE GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS.

THURSDAY...SW SYNOPTIC FLOW IN THE WARM SECTOR WILL STRUGGLE TO
MIX ACROSS ALL BUT OUR WARMEST OUTER GEORGIA WATERS AHEAD OF
ADVANCING COLD FRONT ON THURSDAY. SPEEDS WILL MAINLY BE AT OR EVEN
LESS THAN 15 KT BUT IT COULD BECOME SOMEWHAT GUSTY ALONG THE
LAND/SEA INTERFACE IN THE AFTERNOON. PATCHY TO AREAS OF SEA FOG
COULD CERTAINLY BE LINGERING OVER THE COLDER SHELF WATERS INTO THE
DAY.

THURSDAY NIGHT THROUGH SUNDAY NIGHT...A STRONG COLD FRONT WILL
BLAST THROUGH THE WATERS THURSDAY NIGHT ACCOMPANIED BY SOLID SMALL
CRAFT ADVISORY CONDITIONS AND AT LEAST A SMALL CHANCE FOR GALES
OFF THE CHARLESTON COUNTY COAST AND THE GEORGIA WATERS FROM 20 TO
60 NM. WHILE WINDS SHIFT NNE AND GUST THURSDAY NIGHT INTO
FRIDAY...SEAS WILL BUILD TO 4 TO 6 FT NEAR SHORE AND 8-10 FT WELL
OFF THE GEORGIA COAST. HIGH PRES WILL BUILD OVER THE WATERS DURING
THE WEEKEND WILL NE FLOW DECREASING ON SATURDAY...THEN LIGHTER
MORE VARIABLE WINDS ON SUNDAY INTO EARLY NEXT WEEK.

&&

.CLIMATE...
RECORD HIGHS FOR 4 MARCH...
KCHS... 83/2004
KCXM... 80/1899
KSAV... 84/1955

RECORD HIGHS FOR 5 MARCH...
KCHS... 85/1997
KCXM... 84/1923
KSAV... 86/1955

RECORD LOW MAXIMUMS FOR 6 MARCH...
KCHS... 43/1960
KCXM... 43/1960
KSAV... 42/1901

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...DENSE FOG ADVISORY UNTIL 9 AM EST THIS MORNING FOR SCZ040.
MARINE...DENSE FOG ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ350-
     352-354.
     DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR AMZ374.

&&

$$

ST



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.