Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS62 KILM 230105 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 905 PM EDT MON SEP 22 2014 .SYNOPSIS... AN UPPER LOW WILL IMPACT THE AREA TONIGHT THROUGH MIDWEEK. LIGHT STRATIFORM RAIN WILL BECOME THE MAINSTAY ACROSS THE EASTERN CAROLINAS THROUGH MID TO POSSIBLY LATE WEEK. A STALLED COASTAL TROUGH WILL REMAIN OVER THE ATLANTIC WATERS DURING THIS TIME KEEPING THE THREAT OF STORMS OVER LAND TO A MINIMUM. A WARMING AND DRYING TREND IS EXPECTED BY THE UPCOMING WEEKEND. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... AS OF 9 PM MONDAY...A COLD FRONT WAS SINKING SOUTH THIS MID EVE ALTHOUGH DE-ACCELERATING DUE TO SURFACE WAVE DEVELOPMENT OVER SC INDUCED BY LOCALIZED BUT STRONG HEIGHT FALLS AHEAD OF A VIGOROUS UPPER CIRCULATION. THE SURFACE WAVE YANKED A DEWPOINT GRADIENT BACK NORTHWARD BUT PRESSURE CONTOURS IDENTIFY THE FRONTAL BOUNDARY OFFSHORE OF CAPE FEAR SW INTO THE CHARLESTON SC AREA. MEANWHILE THE LEADING EDGE OF STRONG HIGH PRESSURE POISED TO USHER IN A SENSIBLY DIFFERENT AIR-MASS...WAS POSITIONED DIAGONALLY ACROSS VIRGINIA INTO THE RUGGED TERRAIN OF THE VERY WESTERN CAROLINAS. DEWPOINTS IN THE UPPER 30S WERE MOVING INTO NORTHERN REACHES OF VIRGINIA WITH DEWPOINTS IN THE 40S FROM BOONE TO ASHEVILLE NC. WIDESPREAD BUT LIGHT STRATIFORM PRECIPITATION WAS MOVING NE ACROSS THE INTERIOR EMBEDDED WITH HEAVIER SHOWER POCKETS. WATER VAPOR IMAGERY SHOWS WELL THE ENERGETIC UPPER FEATURE TRIGGERING THE RAIN ONSET...WHOSE CENTER WAS LOCATED OVER SOUTHERN GEORGIA. NO MAJOR CHANGES ARE NEEDED TO THE FORECAST AT THIS TIME AND SHORT FUSE HAZARD POTENTIAL IS VERY LOW BELOW 5 PERCENT FOR CONVECTION THREATS. ADJUSTMENTS ANTICIPATED MAINLY STAYING ALIGNED WITH CHANGEABLE TRENDS IN T/TD/RH. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/... AS OF 300 PM MONDAY...PATTERN ALOFT TO BECOME SOMEWHAT OF A BOTTLE NECK ACROSS THE AREA. MODELS IN UNISON WITH THE DEVELOPMENT OF A CLOSED UPPER LOW ACROSS THE CAROLINAS ON TUESDAY...AND WILL PERSIST ACROSS THE FA THRU WEDNESDAY. POSITIONING OF THIS CLOSED LOW ACROSS WESTERN CAROLINAS WILL RESULT IN S GOOD FEED OF MOISTURE FROM THE ATLANTIC AND TO A LESSER DEGREE FROM THE GULF OF MEXICO. AT THE SFC...STRONG 1035+ MB HIGH CENTERED OVER THE NE STATES WILL RIDGE DOWN THE EAST COAST. JUST OFFSHORE AND LINING UP NEARLY PARALLEL TO THE CAROLINA COASTLINE SOUTH OF CAPE HATTERAS...WILL LIE A COASTAL TROF/FRONT. DURING THIS SHORT TERM PERIOD...DO NOT ANTICIPATE THIS BOUNDARY MOVING ONSHORE VIA MODEL CONSENSUS. WILL BE LOOKING AT OVERRUNNING OR ISENTROPIC LIFT ACROSS THE FA WHICH WILL PRODUCE STRATIFORM-TYPE LIGHT RAINS. A SHARP GRADIENT WILL EXIST WITH RESPECT TO THE MOISTURE DISTRIBUTION ACROSS THE FA...WITH THE HEAVIEST PCPN LIKELY TO OCCUR EAST OF THE I-95 CORRIDOR TO THE IMMEDIATE CAROLINA COASTS. THE POSITIONING OF THIS UPPER LOW ACROSS THE WESTERN AND CENTRAL CAROLINAS WILL DETERMINE WHETHER ADDITIONAL HEAVIER PCPN WILL GET PUSHED INLAND. HAVE INDICATED AN ISOLATED THUNDERSTORM POSSIBLE FOR ANY ELEVATED CONVECTION THAT HOLDS TOGETHER AS IT DEVELOPS IN THE VICINITY OF THE COASTAL FRONT AND PUSHES ONSHORE. AS FOR MAX/MIN TEMPS TUESDAY THRU WEDNESDAY...HAVE LEANED TOWARD THE COOLER GFS MOS GUIDANCE DUE TO CLOUDINESS AND ONGOING PCPN THREAT AS WELL AS THE PRESENT STRONG NE FLOW ACROSS FA THROUGH THIS PERIOD. && .LONG TERM /THURSDAY THROUGH MONDAY/... AS OF 300 PM MONDAY...COOL AIR WEDGE PLUS A COASTAL TROUGH SPELLS SOME RATHER UNSETTLED AND PROBABLY PRETTY COOL WEATHER THURSDAY AND FRIDAY. IN FACT THE MOS GUIDANCE NUMBERS MAY BE SHOWING THEIR BIAS TOWARDS CLIMO THAT INCREASES WITH TIME SINCE THEY PORTRAY TEMPS NEAR CLIMO BOTH DAYS...WHILE KEEPING HIGHS NEAR 70 TOMORROW IN A SIMILAR AIRMASS OFFERING UP CLOUDS AND RAIN. WILL KEEP FORECAST CLOSER TO CURRENT VALUES OF MID 70S FOR HIGHS. RAIN CHANCES WILL BE MOST FOCUSED ALONG THE COAST BOTH DAYS IN PROXIMITY TO THE TROUGH AND DEEPEST MOISTURE AND THE GFS HAS NOW BACKED OFF ALMOST COMPLETELY WITH INLAND PENETRATION OF QPF. THIS IS NOW SUPPORTED BY THE GEM AND SO MAY NEED TO BE REEVALUATED. MID LEVEL RIDGING STRENGTHENS ACROSS THE EASTERN U.S. SUPPRESSING THE DEEP MOISTURE OFF TO OUR SOUTH LIKELY LEADING TO A RAIN-FREE WEEKEND. WHILE THE SENSE OF LOW LEVEL THERMAL ADVECTION OVER THE WEEKEND WILL TECHNICALLY BE NEUTRAL OR EVEN WEAKLY COOL THE RETURN OF SUNSHINE WILL FAVOR SEASONABLE TEMPERATURES DURING THE DAY. THE LESSER CLOUD COVER MEANWHILE COULD BRING SOME COOLER NIGHTS WHEN COMPARED TO EARLIER IN THE PERIOD. && .AVIATION /01Z TUESDAY THROUGH SATURDAY/... AS OF 18Z...A COLD FRONT WILL CONTINUE TO DROP SOUTHWARD...WITH NORTH NORTHEAST WINDS AT ALL TERMINALS. PATCHY LIGHT RAIN MAY BE REPLACED WITH HEAVIER CONVECTION...MAINLY ALONG THE EXTREME SOUTHEASTERN PORTION OF THE CWA...POSSIBLY AFFECTING THE MYRTLES. PREDOMINATELY MVFR CONDITIONS IN THE SHOWERS. TONIGHT...ACTIVITY DIMINISHING WITH CONTINUED NORTHEAST FLOW. THE NAM IS VERY PESSIMISTIC WITH REGARD TO CEILINGS...BRINGING EVERYONE DOWN TO IFR. FELL THIS IS WAY OVERDONE AT THE JUNCTION...BUT KEEP AN OPEN MIND. TUESDAY...A LOW FORMS ALONG THE FRONT AND TRIES TO WAVE THE FRONT BACK ONSHORE...HOWEVER FEEL MOST OF THE MOISTURE WILL STAY OFFSHORE AT THIS TIME. EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THE PERIOD...MAINLY ALONG THE SOUTHEAST COAST OF THE CWA WITH PERIODS OF RAIN/SHOWERS AND INTERMITTENT MVFR/IFR CONDITIONS. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 9 PM...SMALL CRAFT ADVISORY HOISTED THIS EVENING FOR 20-25 KT NE WINDS AND 4-7 FOOT SEAS SET TO ARRIVE FROM AROUND TUESDAY AFTERNOON ONWARD. FOR TONIGHT SUB-ADVISORY CONDITIONS ALTHOUGH THE WATERS WILL CONTINUE TO SEE WINDS INCREASE IN MAGNITUDE AND TURN FROM A NE TRAJECTORY THROUGH TUESDAY MORNING. SIGNIFICANT SEAS WILL BUILD FROM 2-3 FEET TO 3-5 FEET INTO EARLY TUESDAY. SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... AS OF 300 PM MONDAY...STRONG SFC HIGH CENTERED OVER THE NE STATES...WILL RIDGE DOWN THE EASTERN SEA BOARD THRU THIS PERIOD. AT THE SAME TIME...A COASTAL TROF/FRONT WILL MANIFEST ITSELF DURING THIS PERIOD. MODELS KEEP THIS BOUNDARY JUST OFFSHORE FROM THE CAROLINAS COASTLINES. THIS WILL RESULT IN A PINCHED SFC PG ACROSS THE LOCAL WATERS FOR AN EXTENDED PERIOD OF TIME. THIS WILL PRODUCE NE TO ENE 15 TO 25 KT WINDS...WITH FEW GUSTS UP TO 30 KT. SOMEWHAT TOO EARLY FOR THE DAYSHIFT...WILL LET EITHER THE EVENING OR OVERNIGHT SHIFT PUT UP THE EXTENDED SCA. SIGNIFICANT SEAS WILL BUILD AND HOLD IN THE 3 TO 7 FOOT RANGE DEPENDING ON ONES LOCATION IN RELATION TO THE COASTLINE CONFIGURATION. OVERALL...SIG SEAS WILL BECOME MAINLY A FUNCTION OF NE TO ENE WIND WAVES EXHIBITING 5 TO 6 SECOND PERIODS. AN UNDERLYING 1-3 FOOT GROUND SWELL AT 8+ SECOND PERIODS WILL ALSO REMAIN PRESENT. LONG TERM /THURSDAY THROUGH FRIDAY/... AS OF 300 PM MONDAY...A PINCHED NORTHEASTERLY GRADIENT WILL KEEP THE REGION VERY CLOSE TO THE CUSP OF SCEC HEADLINES VS SMALL CRAFT ADVISORY. THE MORE SERIOUS LATTER HEADLINE APPEARS IN THE OFFERING FOR THE EARLIER PART OF THE PERIOD WHILE CONDITIONS MAY DROP DOWN TO SCEC COME SATURDAY. THIS WOULD BE IN RESPONSE TO A BUILDING MID LEVEL RIDGE AND A SLIGHT SOUTHWARD PUSH OF THE MAIN AXIS OF SURFACE HIGH PRESSURE. THERE WILL BE A LONG PERIOD NE SWELL THAT WILL COEXIST WITH THE WIND WAVES...BUT BOTH WILL ALSO EXPERIENCE SOME SHADOWING LOCALLY OFF OF HATTERAS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM NOON TUESDAY TO 6 PM EDT WEDNESDAY FOR AMZ250-252-254-256. && $$ NEAR TERM...COLBY SHORT TERM...DOUGH LONG TERM...BACON AVIATION...ROSS

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