Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 311938 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 338 PM EDT FRI OCT 31 2014 .SYNOPSIS...
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WINDY AND CHILLY FOR SATURDAY WITH SOME SHOWERS. A POWERFUL COLD FRONT WILL CROSS THE REGION SATURDAY MORNING. LOW PRESSURE WILL STRENGTHEN OFF THE NORTH CAROLINA COAST ON SATURDAY AND THEN RAPIDLY INTENSIFY AS IT MOVES TO THE NORTHEAST SATURDAY NIGHT AND SUNDAY. COLD CANADIAN HIGH PRESSURE WILL KEEP IT CHILLY ON SUNDAY AS SUNSHINE RETURNS. TEMPERATURES WILL MODERATE BEGINNING MONDAY AS HIGH PRESSURE MOVES SLOWLY OFFSHORE.
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&& .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
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AS OF 300 PM FRIDAY...MOTHER NATURE IS TRULY PROVIDING US WITH A "TREAT" ON THIS HALLOWEEN...WITH A BEAUTIFUL FALL DAY ONGOING ACROSS THE CWA. BUT RATHER THAN BEING CAST FROM A WITCHES SPELL...A RIDGE OF HIGH PRESSURE IS RESPONSIBLE FOR THE SUNSHINE WHILE A COLD FRONT OFFSHORE IS ASSISTING WITH THE COOL TEMPERATURES. THIS TRANQUIL WEATHER WILL LAST FOR A SHORTER TIME THAN ME GOING THROUGH A HAUNTED HOUSE HOWEVER...AS A STRONG LOW PRESSURE BEGINS TO DEVELOP TONIGHT. THE "TRICK" TO THE FORECAST INVOLVES A RAPIDLY DEEPENING UPPER LOW CURRENTLY ACROSS THE GREAT LAKES. THIS IMPULSE WILL DIG INTO THE CAROLINAS LATE TONIGHT...ALL WHILE DEEPENING TO A GHASTLY -4 TO -5 SD`S BELOW NORMAL WITH RESPECT TO 500MB HEIGHTS. THIS STRONG IMPULSE WILL SPAWN A SURFACE LOW...AND WHILE MOST IMPACTS WILL HOLD OFF UNTIL SATURDAY...DETERIORATING CONDITIONS WILL BE LURKING...WAITING FOR THE SURFACE LOW TO MOVE INTO THE STRONG BAROCLINIC ZONE OFFSHORE BEFORE COMING TO LIFE. GUIDANCE IS ALL UNDER-FORECASTING THE DRY AIR TONIGHT SO HAVE SLOWED SHOWER DEVELOPMENT UNTIL AFTER MIDNIGHT...BUT INCREASING CLOUD COVER WILL CLOAK THE FIRST QUARTER MOON IN AN EERIE VEIL. CANNOT RULE OUT A FEW SHOWERS TONIGHT...MOSTLY WEST OF I-95...SO BE ALERT FOR THAT POTENTIAL AS WELL AS THE GHOSTS AND GOBLINS SURE TO BE ROAMING ABOUT. WINDS WILL EASE TO NEAR CALM AFTER DARK MAKING FOR EASY BROOMSTICK NAVIGATION...BUT ALSO ALLOW TEMPS TO PLUMMET AFTER DARK...SO THAT SHIVER YOU FEEL MAY JUST BE FROM TEMPS IN THE 40S AND NOT A PASSING SPIRIT. MINIMUMS MAY BE REACHED A FEW HOURS BEFORE DAWN HOWEVER AS SW WINDS DEVELOP LATE AHEAD OF THE NEXT COLD FRONT...ALLOWING TEMPS TO RISE FROM THE BOTTOM LIKE A ZOMBIE FROM THE GRAVE BEFORE SUNRISE ON SATURDAY.
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&& .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
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AS OF 300 PM FRIDAY...WINDY AND CHILLY WEATHER EXPECTED FOR SAT WITH AT LEAST A LIKELIHOOD OF SHOWERS. A COLD FRONT WILL BE MOVING ACROSS THE AREA SAT MORNING...USHERING IN A VERY CHILLY AIRMASS. THIS WILL PREVENT TEMPS FROM RISING MUCH THROUGH THE DAY AND WE EXPECT THE DIURNAL RANGE WILL BE UNSEASONABLY SMALL. AN UPPER LOW AND ITS ASSOCIATED LIFT AND ENERGY WILL BE MOVING ACROSS THE FORECAST AREA ON SAT. A SECONDARY AREA OF SURFACE LOW PRESSURE IS EXPECTED TO STRENGTHEN OFFSHORE OF NORTH CAROLINA ON SAT IN RESPONSE TO THE STRONG ENERGY ALOFT. THIS LOW WILL BECOME DOMINATE AS IT MOVES RAPIDLY TO THE NORTHEAST AND AWAY FROM THE AREA SAT NIGHT. AS THE PRESSURE GRADIENT SIGNIFICANTLY TIGHTENS...WIND SPEEDS IN THE 1 TO 2 KFT LAYER WILL INCREASE TO 45 TO 50 KT. NW WINDS AT THE SURFACE WILL INCREASE TO 25 TO 35 MPH WITH THE STRONGEST WINDS EXPECTED DURING THE LATER HALF OF THE AFTERNOON AND SAT NIGHT. WIND GUSTS UP TO 40 TO 45 MPH ARE EXPECTED...HIGHEST ACROSS THE NORTH CAROLINA COAST IN CLOSEST PROXIMITY TO THE STRENGTHENING AREA OF LOW PRESSURE. PORTIONS OF THE FORECAST AREA MAY REQUIRE A WIND ADVISORY WITH LATER FORECASTS. STRONG WINDS WILL ADD TO THE CHILL AS HIGHS ON SAT ARE ONLY EXPECTED TO REACH THE UPPER 40S TO LOWER 50S WITH MID 50S ALONG COASTAL NORTH CAROLINA. LOWS SAT NIGHT WILL FALL TO THE MID 30S INLAND TO UPPER 30S AND LOWER 40S NEARER TO THE COAST. ALTHOUGH WINDS OVERNIGHT SAT WILL BE DIMINISHING...THEY ARE NOT EXPECTED TO GO LIGHT AND SO WE DO NOT EXPECT A FROST EXCEPT PERHAPS IN THE MOST WIND PROTECTED INLAND AREAS NEAR SUNRISE SUN. CHILLY AIR ALOFT ON SAT...AROUND MINUS 25 DEG C...WILL HELP TO INCREASE THE INSTABILITY. DRY AIRMASS WILL MOISTEN BELOW 25 KFT SAT AFTERNOON. COUPLE THE INCREASING MOISTURE WITH THE STRONG DYNAMICS AND WE SHOULD BE ABLE TO WRING OUT NUMEROUS TO WIDESPREAD SHOWERS. GIVEN THE BREVITY AND RATHER SHALLOW NATURE OF THE MOISTURE RETURN...EXPECT RAINFALL AMOUNTS WILL NOT EXCEED A QUARTER OF AN INCH AND MOST PLACES MAY NOT EXCEED A TENTH OF A INCH. SOME OF THE SHOWERS THAT MANAGE TO GAIN SLIGHTLY MORE DEPTH MAY BE ACCOMPANIED BY GRAUPEL. WILL NOT INCLUDE THUNDERSTORMS AT THIS TIME GIVEN WE EXPECT THE CONVECTION TO BE SHALLOW. MIXED LAYER CAPE VALUES WILL BE AT OR BELOW 200 J/KG...EVEN AT THE COAST. HOWEVER...IT IS A VERY DYNAMIC SYSTEM AND SO AN ISOLATED LIGHTNING STRIKE CAN NOT BE RULED OUT. THE RISK FOR THUNDERSTORMS WILL BE HIGHER ACROSS THE WARMER OFFSHORE WATERS. COLD HIGH PRESSURE WILL SLOWLY BUILD ACROSS THE EASTERN CAROLINAS IN THE WAKE OF INTENSE LOW PRESSURE SUN AND SUN NIGHT. THIS WILL SET THE STAGE FOR ANOTHER UNSEASONABLY COLD DAY AND A POSSIBLE FREEZE IN MOST LOCATIONS SUN NIGHT. WINDS WILL BE STRONGEST IN THE MORNING AND THEN DECREASE AS THE PRESSURE GRADIENT CONTINUES TO RELAX. HIGHS ON SUN...EVEN WITH MAINLY SUNNY SKIES...WILL BE IN THE LOWER TO MID 50S. LOWS WILL BE VERY NEAR 32 DEGREES EXCEPT FOR POSSIBLY MID 30S VERY NEAR THE COAST AND AT THE BEACHES.
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&& .LONG TERM /MONDAY THROUGH FRIDAY/...
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AS OF 300 PM FRIDAY...THE EXTENDED WILL FEATURE A LOT OF AMPLITUDE AT THE MID LEVELS FOR MOST OF THE PERIOD. EARLY ON...SHARP RIDGING WILL MOVE ACROSS THE MISSISSIPPI VALLEY AND THEN OFF THE SOUTHEAST COAST AS DEEP TROUGHING DEVELOPS ACROSS THE SOUTHWEST THAT EVENTUALLY CUTS OFF. BY THURSDAY A SHORTWAVE ORIGINATING FROM THE NORTHWEST WILL MOVE ACROSS WITH A DRY FRONT AT THE SURFACE. PRIOR TO THIS AND JUST BEYOND...SURFACE HIGH PRESSURE WILL PREVAIL. THERE IS LITTLE TO NO POPS IN THE FORECAST...JUST SLIGHT CHANCE WITH THIS FRONT LATE WEDNESDAY AND THURSDAY. TEMPERATURE TRENDS SHOW A SLOW MODERATING TREND FOR MONDAY THROUGH THURSDAY WITH VALUES BELOW CLIMATOLOGY FOR THE MOST PART ESPECIALLY MORNING LOWS. HIGHS DO CLIMB BACK INTO THE 70S WEDNESDAY AND THURSDAY BEFORE FALLING BACK SLIGHTLY FRIDAY.
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&& .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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AS OF 18Z...MAINLY NORTHERLY WINDS TODAY AS HIGH PRESSURE SLOWLY RETREATS. TONIGHT...STRONG UPPER LOW WITH AN UNSEASONABLY COLD CORE WILL APPROACH THE REGION FROM THE NORTHWEST. NOT MUCH WILL HAPPEN OVERNIGHT AS WE GET DRY SLOTTED AND THE GRADIENT AND COLD AIR ADVECTION WILL NOT COMMENCE UNTIL MORNING...SO WHILE A BRIEF SHOWER CANNOT BE RULED OUT...THE TERMINALS WILL LIKELY REMAIN DRY UNTIL THE MORNING. A BRIEF PERIOD OF NEAR CALM WINDS IS EXPECTED OVERNIGHT BEFORE STEADILY INCREASING TOWARDS DAWN AND ESPECIALLY ON SATURDAY. GRADIENT INCREASES EVEN FURTHER JUST AFTER THE END THE FORECAST PERIOD...HOWEVER ANY SHOWERS THAT DO OCCUR SATURDAY WILL BUMP THE WINDS UP. EXTENDED OUTLOOK...BREEZY TO WINDY CONDITIONS TO PERSIST INTO SUNDAY AFTER LOW PRESSURE DEVELOPS OFF THE CAROLINA COAST...AND ACCELERATES TO THE NE. VFR FOR MONDAY AND TUESDAY AS THE CENTER OF STRONG HIGH PRESSURE MOVES OVERHEAD. LIGHT MORNING FOG POSSIBLE WEDNESDAY.
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&& .MARINE...
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NEAR TERM /THROUGH TONIGHT/... AS OF 300 PM FRIDAY...STRENGTHENING LOW PRESSURE IS CENTERED WELL TO THE EAST OF THE NC/VA BORDER...AND WILL CONTINUE TO MOVE NORTHEAST ALONG A STALLED BOUNDARY TONIGHT. A WEAK HIGH PRESSURE HAS RIDGED INTO THE CAROLINAS THIS AFTN...SEPARATING THE LOW PRESSURE OFFSHORE FROM A STRONG COLD FRONT APPROACHING FROM THE WEST...AND THUS THE GRADIENT WILL CONTINUE TO WEAKEN TONIGHT. CURRENT N/NE WINDS OF 10-15 KTS WILL SLOWLY EASE TO BECOME LIGHT AND VARIABLE OVERNIGHT...BEFORE RISING ONCE AGAIN FROM THE W/SW AHEAD OF THE NEXT COLD FRONT BY SATURDAY MORNING. SEAS HAVE BEEN PERSISTENTLY 3-5 FT TODAY...BUT ARE EXPECTED TO FALL FOR A SHORT TIME TO 2-4 FT TONIGHT BEFORE RISING AGAIN BY DAWN...BUT WITH THE NE WIND WAVE REPLACED BY AN AMPLIFYING SW CHOP. A GALE WARNING HAS BEEN ISSUED BUT WILL BEGIN SHORTLY AFTER THE NEAR TERM. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 PM FRIDAY...A GALE WARNING IS IN EFFECT SAT AFTERNOON AND NIGHT WITH A PERIOD OF SMALL CRAFT ADVISORY CONDITIONS EXPECTED INTO SUN. AS LOW PRESSURE STRENGTHENS OFF THE NORTH CAROLINA COAST AND THE PRESSURE GRADIENT TIGHTENS...SUSTAINED WINDS SHOULD REACH GALE FORCE WITH GUSTS AS HIGH AS 40 TO 45 KT. THE STRONGEST WINDS ARE EXPECTED LATER SAT AFTERNOON AND ESPECIALLY SAT NIGHT. SEAS WILL EXCEED 6 FT ACROSS PORTIONS OF THE WATERS BY MIDDAY SAT AND UP TO 6 TO 8 FT SAT NIGHT. NEAR SHORE...SEAS WILL BE LOWER GIVEN THE STRONG OFFSHORE FLOW. IN THE WAKE OF INTENSE LOW PRESSURE...WINDS AND SEAS WILL SUBSIDE SUN AND SUN NIGHT. A BLOW OUT TIDE MAY OCCUR WITH LOW TIDE SAT EVE AND AGAIN SUN MORNING. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM FRIDAY...A FEW HOURS OF STRONGER NORTHWEST WINDS WILL CONTINUE MONDAY BEFORE SETTLING DOWN TO ESSENTIALLY LIGHT AND VARIABLE BY DAYS END. THIS AS HIGH PRESSURE SETTLES OVERHEAD. THE LIGHT WINDS WILL CONTINUE FOR THE REMAINDER OF THE PERIOD AS HIGH PRESSURE IS SLOW TO MOVE AND THE AXIS ELONGATES TO KEEP WINDS BENIGN. SEAS WILL MIRROR THE LIGHT WINDS WITH ONE TO TWO FEET THROUGH THE PERIOD.
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&& .ILM WATCHES/WARNINGS/ADVISORIES...
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SC...NONE. NC...NONE. MARINE...GALE WARNING FROM NOON EDT SATURDAY TO 6 AM EST SUNDAY FOR AMZ250-252-254-256.
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&& $$ NEAR TERM...JDW SHORT TERM...RJD LONG TERM...SHK AVIATION...JDW/DL

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