Area Forecast Discussion
Issued by NWS Wilmington, NC

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000 FXUS62 KILM 300148 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 948 PM EDT FRI APR 29 2016 .SYNOPSIS... HIGH PRESSURE WILL BUILD IN WEAKLY FROM THE NORTH THROUGH SATURDAY. ISOLATED SHOWERS WILL BE POSSIBLE ACROSS WESTERN AREAS SATURDAY AFTERNOON AND EVENING. LOW PRESSURE MOVING ACROSS THE MID- ATLANTIC STATES MAY BRING SEVERAL DAYS OF UNSETTLED WEATHER WITH PERIODS OF RAINFALL SUNDAY THROUGH TUESDAY. SHOWERS WILL BECOMING MORE ISOLATED ON WEDNESDAY. TEMPERATURES WILL COOL A LITTLE LATE IN THE PERIOD WITH DRY WEATHER EXPECTED THURSDAY AND FRIDAY. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... AS OF 1000 PM FRIDAY...CONVECTIVE CLOUD DEBRIS WAS THINNING AS IT MOVED ACROSS THE EASTERN CAROLINAS. THIS SHOULD CONTINUE TO BE THE CASE AS THESE CLOUDS MOVE EAST AND INTO PROGRESSIVELY DRIER AIR. STILL EXPECT CONSIDERABLE LOW CLOUDS TO DEVELOP OVERNIGHT AS MOISTURE GETS TRAPPED BENEATH A STRONG NEAR SURFACE INVERSION. THIS SHOULD RESULT IN LOW STRATUS AND WE HAVE SEEN SOME OF THESE LOWER CLOUDS FILTERING ACROSS THE AREA. STRATUS MAY WORK DOWN TO THE SURFACE AS BOUNDARY LAYER WINDS WILL BE RATHER LIGHT. WILL INCLUDE PATCHY TO AREAS OF FOG AT THIS TIME...AS DEWPOINTS IN THE LOWER TO MID 60S ARE VERY NEAR THE LOW TEMPERATURE FORECAST. A NORTHERLY SURGE IS EXPECTED TO GET UNDERWAY SAT MORNING AS A RIDGE OF HIGH PRESSURE TO OUR N BUILDS SOUTHWARD. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/... AS OF 300 PM FRIDAY...LOW PRESSURE SPINNING WELL EAST OF THE VIRGINIA COAST WILL PUSH ANOTHER NORTHEASTERLY SURGE DOWN OUR COAST SATURDAY MORNING. THIS SHOULD INCREASE WIND SPEEDS AS FAR SOUTH AS MYRTLE BEACH TO 10-15 MPH AND WILL HELP HOLD DAYTIME TEMPERATURES SEVERAL DEGREES COOLER THAN WHAT WE EXPERIENCED TODAY. THERE ARE GREAT DIFFERENCES BETWEEN THE 12Z NAM AND GFS WITH REGARD TO HOW MUCH LOW CLOUDINESS PERSISTS THROUGH THE DAY AFTER EARLY MORNING DEVELOPMENT. THE NAM MAINTAINS MUCH MORE CLOUDINESS AND THEREFORE HAS MUCH COOLER TEMPERATURES THAN ANY OTHER MODEL. I AM FAVORING THE WARMER/DRIER GFS WITH THE EXPECTATION THAT WE`LL SEE STRATUS ERODE SIMILARLY TO WHAT WE EXPERIENCED THIS MORNING GIVEN A SIMILAR SHALLOW DEPTH TO THE CLOUD DECK. STILL TEMPERED BY THE STRONGER ONSHORE WINDS HIGHS SHOULD REACH THE UPPER 70S NEAR THE COAST AND LOWER TO MID 80S FARTHER INLAND...WARMEST NEAR FLORENCE AND KINGSTREE. LOW PRESSURE MOVING EASTWARD FROM THE PLAINS STATES SATURDAY INTO THE OHIO VALLEY SUNDAY WILL DIRECT A SERIES OF UPPER LEVEL DISTURBANCES ACROSS THE CAROLINAS ALONG WITH PERIODS OF INCREASED MID AND HIGH LEVEL MOISTURE. OUR LOW-LEVELS WILL ALSO MOISTEN UP APPRECIABLY LEADING TO INLAND CONVECTIVE INSTABILITY OF 500 J/KG SATURDAY AND AS HIGH AS 1250 J/KG SUNDAY. I HAVE NOT RAISED FORECAST POPS ANY COMPARED TO PREVIOUS FORECASTS AND IN FACT HAVE TRIMMED THEM BACK FROM THE COAST WHERE COOLER MARITIME AIR SHOULD REDUCE EFFECTIVE INSTABILITY COMPARED TO FARTHER INLAND. A 20 POP IS FORECAST ALONG AND WEST OF I-95 SATURDAY...INCREASING TO 30-40 PERCENT SUNDAY. THE BEST COVERAGE OF SHOWERS AND STORMS SHOULD REMAIN ACROSS THE WESTERN CAROLINAS WHERE MUCH BETTER SYNOPTIC LIFT SHOULD EXIST. && .LONG TERM /MONDAY THROUGH FRIDAY/... AS OF 300 PM FRIDAY...COLD FRONT IN THE AREA AS THE PERIOD BEGINS IS EXPECTED TO STALL ACROSS OR JUST SOUTH OF THE AREA EARLY NEXT WEEK. THE PROXIMITY TO THE FRONT AND THE ABUNDANCE OF DEEP MOISTURE MON INTO WED...AN EXTENDED PERIOD OF PWATS ABOVE 1.5 INCHES IS EXPECTED...WILL KEEP PRECIP CHANCES ELEVATED FOR THE FIRST HALF OF NEXT WEEK. THERE WILL BE WAVES MOVING ALONG THE FRONT INCREASING PRECIP CHANCES AS THEY PASS...THOUGH TIMING THESE AT EXTENDED TIME RANGES IS SOMEWHAT DIFFICULT. THE PATTERN ALOFT WILL REMAIN PROGRESSIVE...DEVOID OF ANY SIGNIFICANT MID LEVEL FEATURES THAT WOULD ENHANCE OR SUPPRESS CONVECTION UNTIL TUE NIGHT OR EARLY WED. TUE INTO WED A 5H TROUGH/LOW OVER THE SOUTHWEST CONUS WILL MOVE EAST...INTERACTING WITH A MID LEVEL TROUGH DROPPING SOUTH ACROSS THE GREAT LAKES. THE EASTWARD MOVEMENT OF LONGWAVE 5H TROUGH HELPS PUSH THE STALLED FRONT AND ASSOCIATED DEEP MOISTURE OVER THE SOUTHEAST OFF THE COAST....DRYING THE REGION OUT. PLENTY OF UNCERTAINTY CONCERNING THE FATE OF THE 5H TROUGH/LOW THU FRI WITH THE GFS MORE PROGRESSIVE...MOVING THE FEATURE OFF THE COAST LATE THU. THE ECMWF IS MUCH LESS PROGRESSIVE AND KEEPS THE 5H TROUGH/LOW OVER THE SOUTHEAST INTO THE WEEKEND. BOTH SOLUTIONS DO OFFER A PERIOD OF DRY WEATHER...THOUGH THE ECMWF SOLUTION COULD YIELD AFTERNOON SHOWERS ON FRI. TEMPS ABOVE CLIMO MON THROUGH WED DIP BELOW CLIMO THU AND FRI...POTENTIALLY WELL BELOW CLIMO IF THE ECMWF SOLUTION VERIFIES. && .AVIATION /00Z SATURDAY THROUGH WEDNESDAY/... AS OF 00Z...WEAK HIGH PRESSURE WILL RESIDE OVER THE REGION THROUGH THE FORECAST PERIOD. A WARM FRONT WILL MOVE NORTH OF MOST OF THE REGION THIS EVENING WITH WEAK SOUTHEAST FLOW. MOISTURE PROFILES INDICATE A SOLID CHANCE FOR STRATUS/FOG OVERNIGHT. THE FLY IN THE OINTMENT WILL BE THE DEBRIS CIRRUS MOVING OVER THE REGION FROM A LARGE MCS CURRENTLY OVER ALABAMA. IF THE CIRRUS BECOMES DENSE ENOUGH IT COULD HINDER FOG FORMATION. MAINLY EASTERLY FLOW ON SATURDAY. QUITE A BIT OF CLOUDS JUST TO THE NORTH OF THE REGION AND THEY WILL NEED TO BE WATCHED CLOSELY. EXTENDED OUTLOOK...BRIEF MVFR/IFR POSSIBLE FROM CONVECTION SUNDAY INTO TUESDAY. OTHERWISE VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 1000 PM FRIDAY...A NORTHERLY SURGE IS EXPECTED TO BEGIN SAT MORNING. WINDS WILL BE FROM THE E OR ESE TONIGHT. THE DIRECTION WILL BACK TO NE SAT MORNING...FIRST ACROSS THE NORTHERN WATERS. WIND SPEEDS WILL BE 10 KT OR LESS...INCREASING AFTER SUNRISE. SEAS WILL BE 2 FT...BUT THEY WILL BUMP UP AS THE BRIEF AND MODEST SURGE GETS UNDERWAY. HIGH PRESSURE TO THE N WILL BUILD SOUTHWARD IN THE WAKE OF DEPARTING LOW PRESSURE SEVERAL HUNDRED MILES OFF THE MID-ATLANTIC COAST. SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... AS OF 300 PM FRIDAY...A RENEWED SURGE OF EAST-NORTHEAST WINDS IS EXPECTED TO MOVE DOWN THE COAST SATURDAY MORNING. THIS SURGE SHOULD DEVELOP AROUND DAYBREAK NORTH OF CAPE FEAR...SHOWING UP ALONG THE GRAND STRAND DURING THE LATE MORNING HOURS. WIND SPEEDS SHOULD INCREASE TO A SOLID 15 KT WITH SEAS BUILDING TO 3 FEET ACROSS OPEN WATERS. THIS IS THE RESULT OF LOW PRESSURE SPINNING WELL OFF THE VIRGINIA COAST. AS THIS LOW SCOOTS FARTHER OFFSHORE DURING THE DAY WIND SPEEDS SHOULD SLOWLY WEAKEN AND DIRECTIONS WILL VEER MORE SOUTHEASTERLY SATURDAY NIGHT. ATTENTION WILL THEN SHIFT TO LOW PRESSURE MOVING EASTWARD FROM THE PLAINS STATES INTO THE OHIO VALLEY SUNDAY. THIS SHOULD TURN OUR WINDS SOUTHERLY WITH SPEEDS AGAIN INCREASING TO 15 KNOTS. ALTHOUGH ISOLATED SHOWERS WILL BE POSSIBLE SUNDAY AND SUNDAY NIGHT...THE BULK OF ANY PRECIPITATION SHOULD REMAIN WELL INLAND THROUGH SUNDAY EVENING...PERHAPS JUMPING DOWN TO THE COAST LATE SUNDAY NIGHT. LONG TERM /MONDAY THROUGH WEDNESDAY/... AS OF 300 PM FRIDAY...SOUTHWEST FLOW MON WILL WEAKEN MON NIGHT INTO TUE AS SLOW MOVING COLD FRONT DROPS INTO THE AREA FROM THE NORTHWEST. FRONT PUSHES SOUTHEAST OF THE WATERS EARLY TUE...THOUGH HOW FAR SOUTH REMAINS IN QUESTION. AS EARLY AS TUE NIGHT THE FRONT WILL BE BACK IN THE AREA...LINGERING OVER OR JUST WEST OF THE WATERS THROUGH THE END OF THE PERIOD. MON WILL BE THE ONLY DAY WITH WELL DEFINED FLOW...WINDS WILL BE OUT OF THE SOUTHWEST WITH SPEEDS OF 15 TO 20 KT AND SEAS RUNNING 3 TO 5 FT. WINDS TUE AND WED WILL BE DETERMINED BY THE LOCATION OF THE FRONT...BUT GENERALLY EXPECT NORTHERLY WINDS UNDER 10 KT TUE WITH SOUTHERLY FLOW AROUND 10 KT WED. LIGHT WINDS AND CHANGEABLE DIRECTION WILL KEEP SEAS 2 TO 3 FT TUE AND WED. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$ NEAR TERM...RJD SHORT TERM...TRA LONG TERM...III AVIATION...DL

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