Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 300532
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
132 AM EDT SAT APR 30 2016

.SYNOPSIS...
HIGH PRESSURE WILL BUILD FROM THE NORTH TODAY BRINGING COOLER
TEMPERATURES AND A FEW SHOWERS INLAND THIS AFTERNOON AND EVENING.
SEVERAL LOW PRESSURE SYSTEMS PASSING INLAND OF THE AREA...WILL
BRING INCREASING CHANCES OF RAIN SUNDAY THROUGH TUESDAY...WITH
SLIGHT DRYING THROUGH MID WEEK. A COLD FRONT WILL CROSS THE COAST
LATE IN THE WEEK...BRINGING SHOWERS AND COOLER TEMPERATURES.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 132 AM SATURDAY...NO CHANGES WITH THE EARLY MORNING
UPDATES...MAIN CHALLENGE IS EXTENT OF POST FRONTAL STRATUS EARLY
THIS MORNING. THE PREVIOUS DISCUSSION FOLLOWS.

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 THIS 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 /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...MOISTURE PROFILES INDICATE A CHANCE FOR STRATUS/FOG
OVERNIGHT. THE UNCERTAINTY WILL BE THE DEBRIS CIRRUS MOVING OVER
THE REGION FROM A LARGE MCS. IF THE CIRRUS BECOMES DENSE ENOUGH
IT COULD HINDER FOG FORMATION. MAINLY EASTERLY FLOW TODAY WITH A
STATIONARY BOUNDARY JUST TO OUR NORTH KEEPING NORTHERN TERMINALS
IN A MVFR STRATOCU CEILING...POSSIBLY IFR 10Z-15Z THIS MORNING AND
01Z ONWARD TONIGHT.

EXTENDED OUTLOOK...IFR EARLY SUNDAY. BRIEF MVFR/IFR POSSIBLE FROM
CONVECTION SUNDAY AFTERNOON THROUGH TUESDAY...OTHERWISE VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 132 AM SATURDAY...A NORTHERLY SURGE IS EXPECTED TO BEGIN
THIS MORNING. WINDS WILL BE FROM THE E OR ESE OVERNIGHT. THE
DIRECTION WILL BACK TO NE...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.

&&

$$

SYNOPSIS...8
NEAR TERM...RJD/8
SHORT TERM...TRA
LONG TERM...III
AVIATION...DL/8


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