Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 280600 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 200 AM EDT FRI AUG 28 2015 .SYNOPSIS... A WEAK FRONT WILL MEANDER NEAR THE COAST AND DISSIPATE THROUGH FRIDAY. HIGH PRESSURE WILL SLOWLY BUILD INTO THE CAROLINAS OVER THE WEEKEND. ERIKA IS EXPECTED TO APPROACH THE BAHAMAS AND SOUTH FLORIDA LATE IN THE WEEKEND INTO EARLY NEXT WEEK...AND MAY AFFECT THE CAROLINAS BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... AS OF 1015 PM THURSDAY...OTHER THAN A SINGLE SHOWER NEAR GEORGETOWN SC THE FORECAST AREA IS NOW CONVECTION-FREE. GIVEN PROXIMITY OF FRONT JUST OFFSHORE WILL BE MAINTAINING SLIGHT CHANCE POPS FOR THE COASTAL COUNTIES WITH DRY WEATHER INLAND. HRRR DROPS ALL SHOWER ACTIVITY AFTER 3Z...SO THIS COULD WELL BE IT FOR THE OVERNIGHT PERIOD. PREVIOUS DISCUSSIONS FOLLOW: CONVECTION HAS BEEN GRADUALLY FADING WITH THE SETTING SUN AND IS NOW LIMITED TO ISOLATED SHOWERS MAINLY WITHIN 20 NM OF THE COAST. NO LIGHTNING OVER LAND IS NOW IN EVIDENCE. THE FRONT REMAINS STALLED JUST OFFSHORE AND WITH A RELATIVELY COOL NELY FLOW IN ITS WAKE EXPECT THAT WE ARE DONE WITH STRONG CONVECTION FOR THE NIGHT. HAVE DROPPED POPS FOR THE NEAR TERM...MAXING OUT AT 20 PERCENT FOR SLIGHT CHANCE OF SHOWERS...MAINLY OVER OUR COASTAL COUNTIES. STATIONARY BOUNDARY REMAINS STALLED JUST OFFSHORE...WITH COOL NE WINDS PERSISTING ACROSS THE CWA. CLOUD COVER HAS BEEN EXTENSIVE TODAY AS EXPECTED...WITH ONLY PARTIAL BREAKS OF SUNSHINE LOCALLY. THE COOL NE WIND COMBINED WITH THESE CLOUDS HAVE KEPT HIGHS FROM REACHING MUCH OUT OF THE LOWER 80S...SEVERAL DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. THE BENEFIT OF THESE COOLER TEMPS HAS BEEN A LACK OF DEEP INSTABILITY AND HENCE CONVECTION HAS BEEN SLOW TO DEVELOP...AND WEAK IN INTENSITY. SCATTERED SHOWERS ARE DEVELOPING ALONG THE WEAK SEA BREEZE AND SOME DIFFERENTIAL HEATING BOUNDARIES INLAND...AND THIS WILL CONTINUE THROUGH THE EVENING. HOWEVER...UNLIKE THE PAST FEW DAYS...SHOWERS AND ISOLATED TSTMS WILL REMAIN WEAK...AND NO SIGNIFICANT WEATHER CONCERNS ARE EXPECTED. WITH PWATS HIGH AND STORM MOTION SLOW...SOME BRIEF AND ISOLATED FLOODING COULD OCCUR BENEATH ANY STRONGER SHOWER HOWEVER. CONVECTION WILL WANE QUICKLY AFTER DARK...AND A PRIMARILY DRY EVENING OVERNIGHT IS ANTICIPATED. THE EXCEPTION MAY BE ONCE AGAIN NEAR THE COAST WHERE SHOWERS OVER THE WATER MAY ADVECT TOWARDS SHORE...AND A 20 POP HAS BEEN MAINTAINED FOR CONSISTENCY AND POTENTIAL. LOWS TONIGHT WERE DERIVED FROM A BLEND OF THE MAV/MET GUIDANCE WHICH HAS PERFORMED WELL THE PAST FEW NIGHTS. HAVE BUMPED VALUES UP A BIT FROM A STRAIGHT CONSENSUS TO ACCOUNT FOR EXPECTED STRATUS TONIGHT HOWEVER...BUT LOWS WILL DROP TO AROUND 68 WELL INLAND...TO NEAR 72 ALONG THE GRAND STRAND. && .SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...DEEPER MOISTURE CIRCULATING AROUND THE CENTER OF HIGH PRESSURE OFFSHORE ALONG 30N...COUPLED WITH DRY WEST FLOW AT AND ABOVE MOUNTAIN TOP LEVEL WILL IMPART MID-LVL INHIBITION THROUGH FRIDAY AND MUCH OF SATURDAY. FOR THIS REASON POP VALUES WILL REMAIN FAVORED ALONG AND COASTAL INTERIOR. MAX AND MIN TEMPERATURE VALUES THIS PERIOD WILL CLOSELY REPRESENT CLIMATOLOGY FOR LATE AUGUST. A FEW TSTMS WILL REMAIN POSSIBLE INTO PEAK DIURNAL HEATING AND OFFSHORE IN THE PRE-DAWN HOURS BUT OVERALL ISOLATED TO LOW-END SCATTERED COVERAGE ENVISIONED. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 3 PM THURSDAY...THE MID LEVEL PATTERN WILL BE VERY WEAK THROUGH THE PERIOD AND MOST OF THE ATTENTION WILL PROBABLY BE SWAMPED BY TROPICAL ENTITY ERIKA. OBVIOUSLY A LOT OF UNCERTAINTY REMAINS WITH THIS SYSTEM AND WILL BASE THE EXTENDED FORECAST SANS THE VERY LOW TROPICAL PWS GRIDS ON THE WPC GRAPHICS PROVIDED AT 1800 UTC. BASICALLY WEAK HIGH PRESSURE WILL COVER THE AREA WITH GOOD PRECIPITABLE WATERS...HOVERING JUST BELOW TWO INCHES. MAINTAINED THE LOW CHANCE POPS ACROSS THE BOARD WITH HIGHER VALUES DURING THE DAYTIME HOURS PER THE STANDARD MESOSCALE FORCING. TEMPERATURE GUIDANCE LOOKS CONSISTENT WITH MID AND UPPER 80S FOR HIGHS AND LOWER TO MIDDLE 70S FOR LOWS. && .AVIATION /06Z FRIDAY THROUGH TUESDAY/...
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AS OF 06Z...POTENTIAL PERSISTS FOR AREAS OF MVFR/IFR DUE TO STRATUS AND FOG DEVELOPMENT LATE OVERNIGHT INTO THE EARLY MORNING HOURS ON FRIDAY. OTHERWISE EXPECT VFR WITH VCSH/VCTS THROUGHOUT THE PERIOD. A FRONTAL SYSTEM REMAINS JUST OFFSHORE WITH RADAR IMAGERY DEPICTING SCATTERED SHOWERS ACROSS THE OFFSHORE WATERS. LATEST GUIDANCE CONTINUES TO DEPICT POTENTIAL FOR THE DEVELOPMENT OF PATCHY FOG AND STRATUS...WHICH COULD CREATE PERIODS OF MVFR/IFR. AFTER DAYBREAK ON FRIDAY...CONDITIONS WILL IMPROVE TO VFR AND NORTHEAST WINDS WILL INCREASE TO AOB 12 KTS...WITH OCCASIONAL HIGHER GUSTS POSSIBLE. A WIND-SHIFT TO THE EAST WILL OCCUR INTO THE AFTERNOON HOURS...WITH VCSH/VCTS POSSIBLE THROUGH THE REST OF THE PERIOD. INTO THE EVENING HOURS...ANY LINGERING ACTIVITY WILL DISSIPATE AND WINDS WILL BECOME LIGHT. EXTENDED OUTLOOK...PREDOMINATELY VFR WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE EXTENDED. BRIEF MORNING FOG/STRATUS IS ALSO EXPECTED EACH DAY.
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&& .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1015 PM THURSDAY...LATEST OBS CONTINUE TO SHOW SEAS RIGHT AROUND 3 FT WITH MOSTLY NELY WINDS. SEAS AT 41110 DID MAKE IT UP AROUND 4 FT AS SOME NEARBY SHOWERS KICKED UP THE WINDS A BIT. THE COLD FRONT REMAINS STATIONARY AND MOSTLY EAST OF THE WATERS. FORECAST IN GOOD SHAPE AND HAVE MADE NO CHANGES WITH THE LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS: STATIONARY FRONT REMAINS IN PLACE OFFSHORE SERVING AS A FOCUS FOR A FEW SHOWERS AS WELL AS VARIABLE WIND DIRECTIONS. WINDS BEHIND THE FRONT...WHICH IS LOCATED SOUTH OF NEARLY ALL THE WATERS EXCEPT AMZ256...ARE NE AROUND 10 KTS. ON THE SOUTH SIDE OF THIS BOUNDARY...SOUTHERLY WINDS EXIST WITH SIMILAR SPEEDS. THIS FRONT IS NOT EXPECTED TO MOVE MUCH BUT MAY WAVER BACK AND FORTH THROUGH TONIGHT...SO WIND SHIFTS ARE POSSIBLE BUT FORTUNATELY SPEEDS WILL REMAIN LIGHT. ALTHOUGH WINDS ARE WEAK...WAVE HEIGHTS ARE 2-4 FT ACROSS THE WATERS...THANKS PRIMARILY TO AN 10-11 SEC SWELL OF 2-3 FT THAT REMAINS IN THE SPECTRUM. THE NE WINDS ATOP THIS SWELL WILL AT TIMES CREATE A SOMEWHAT CONFUSED SEA STATE...BUT THE SWELL WILL REMAIN THE PRIMARY WAVE GROUP THROUGH TONIGHT. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...NE WINDS TO START THE PERIOD AS A SURFACE HIGH PRESSES SOUTHWARD FROM THE VIRGINIAS...AND A FRONT REMAINS OFFSHORE. MARINE TSTMS MAY ERUPT AGAIN INTO EARLY FRIDAY ALONG THE FRONT AND COULD APPROACH CAPE FEAR OR IMPACT THE 0-20 NM WATERS. THE SC WATERS WILL REMAIN FAVORED FOR THE MOST COVERAGE. NO WAVE HEIGHT INCREASES OF SIGNIFICANCE ARE EXPECTED THROUGH SATURDAY ASSOCIATED WITH ERIKA...BUT MAY BY LATE SUNDAY A FOOT OR TWO. SEAS THIS PERIOD ESE 2-3 FT EVERY 10-11 SECONDS WITH A LIGHT TO MODERATE NE CHOP. LATE SATURDAY WIND DIRECTION MAY VEER TO SE AS THE SURFACE HIGH WEAKENS AND MOVES OFFSHORE. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 3 PM THURSDAY...A WEAK PRESSURE PATTERN THROUGH ALL LEVELS OF THE ATMOSPHERE EQUATE TO VERY WEAK WIND FIELDS THROUGH THE PERIOD. THERE IS A SLIGHT INCREASE IN SPEEDS LATE IN THE PERIOD (TUESDAY) AS TROPICAL ENTITY ERIKA MOVES CLOSER WITH THE DISCLAIMER MUCH UNCERTAINTY EXISTS WITH THIS SYSTEM. SHOULD SEE EAST TO SOUTHEAST WINDS OF TEN KNOTS OR LESS SUNDAY AND MONDAY WITH AN INCREASE TO 10- 15 KNOTS TUESDAY. SIGNIFICANT SEAS WILL HAVE DECENT AND VARIOUS SWELL COMPONENTS FROM CURRENT AND PREVIOUS TROPICAL SYSTEMS AND WILL BE 2-4 FEET SUNDAY AND MONDAY INCREASING SLIGHTLY FOR TUESDAY. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ SYNOPSIS...MJC NEAR TERM...REK/JDW SHORT TERM...MJC LONG TERM...SHK AVIATION...DCH/SGL

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