Area Forecast Discussion
Issued by NWS Wilmington, NC

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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
000
FXUS62 KILM 210518
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1217 AM EDT SUN SEP 21 2014

.SYNOPSIS...
DEEPENING LOW PRESSURE OFFSHORE OF SOUTH CAROLINA WILL TRACK TO
THE NORTHEAST. THE LOW WILL REMAIN OFFSHORE BUT WILL BRING GUSTY
WIND AND COASTAL RAIN OVERNIGHT INTO SUNDAY. A COLD FRONT WILL
CROSS THE COAST ON MONDAY...BRINGING BELOW NORMAL TEMPERATURES
TUESDAY AND WEDNESDAY. RAIN CHANCE MAY INCREASE LATE IN THE WEEK
AS A WARM FRONT LIFTS NORTH ACROSS THE AREA.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1130 PM SATURDAY...OCEAN RAIN WITH EMBEDDED HEAVIER SHOWERS
CONTINUES MAINLY OFFSHORE THIS LATE EVENING. LATEST SURFACE CHART
SHOWS A SURFACE LOW POSITIONED AROUND 150 MILES SSE OF BALD HEAD
ISLAND. NO WEIGHTY OR MOMENTOUS CHANGES TO THE FORECAST WERE MADE
WITH THE LATE EVENING UPDATE. MINIMUM TEMPERATURES REMAIN ON
TARGET WITH LOW/MID 60S INLAND TO THE UPPER 60S COASTAL INTERIOR
AND 70-74 IMMEDIATE COAST AND ADJACENT ICWW LOCALS. MOST RECENT
SATELLITE TRENDS SUGGEST THAT PARTIAL CLEARING MAY UNFOLD ACROSS
OUR DEEP INTERIOR. AS A RESULT WE HAVE LOWERED MINIMUMS A DEGREE
OR 2 FAR INLAND WHERE THIS IS EXPECTED. HIGHEST QPF VALUES REMAIN
ALONG AND NEAR THE COAST. A PAUCITY OF RAINFALL COVERAGE OFFSHORE
DUE TO APPROACHING DRY SLOT AND SUBSIDENCE BETWEEN BANDING
FEATURES CONSTITUTES LIKELY AND HIGH SCATTERED POP VALUES ALONG
AND NEAR THE COAST AS OPPOSED TO FLAT OUT CATEGORICAL/WIDESPREAD.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...THE MID LEVEL COMPONENT OF THE SYSTEM
CURRENTLY MOVING UP THE COAST WILL BE SHEARING OUT AND MOVING
OUT QUICKLY AS WILL THE SURFACE LOW AT THE BEGINNING OF THE
PERIOD. I HAVE MAINTAINED RESIDUAL MINIMAL POPS FOR THE COASTAL
AREAS FOR A FEW HOURS SUNDAY TO ADDRESS. LATE SUNDAY MORNING AND
AFTERNOON SHOULD SEE A RAPID CLEARING WITH HIGHS IN THE MIDDLE 80S
WITH HIGHER VALUES INLAND WHERE THERE WILL BE A LONGER PERIOD OF
INSOLATION. THE FORECAST THEN SHIFTS TO THE SYSTEM CURRENTLY SEEN
IN WATER VAPOR IMAGERY MOVING ACROSS NORTH DAKOTA.

THIS SYSTEM WILL MOVE ACROSS LATE MONDAY WITH AN ATTENDANT COLD
FRONT. GUIDANCE REMAINS UNIMPRESSED WITH CONVECTION REGARDING THIS
SYSTEM AND HAVE CONTINUED TO ADVERTISE SLIGHT CHANCE POPS. THE
COOLER AIR MASS IN THE WAKE OF THE FRONT WILL BE THE BIGGER
STORY...AND GUIDANCE IS ADVERTISING 55 IN THE MAV AND MET IN LBT FOR
TUESDAY MORNING. THE MIXED BOUNDARY LAYER WILL LIKELY PRECLUDE THESE
MINIMAL VALUES BUT WE COULD SEE A LOT OF UPPER 50S INLAND AT THIS
TIME.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...RIGHT ON CUE THE AREA SEEMS TO BE IN FOR SOME
FALL-LIKE WEATHER. HIGH PRESSURE CENTERED OVER THE OHIO VALLEY WILL
COVER MUCH OF THE EASTERN HALF OF THE NATION. THIS IS A BIT FURTHER
SOUTH THAN WHAT WAS PROGGED YESTERDAY, BETTER SUPPRESSING FRONTAL
MOISTURE OFF TO OUR SOUTH FOR WHAT SHOULD AMOUNT TO A FAIR AMOUNT OF
SUNSHINE. DESPITE THE SUNSHINE TEMPERATURES WILL AVERAGE A FEW
DEGREES BELOW CLIMATOLOGY IN A WEAKENING COOL ADVECTION REGIME.
SIMILARLY A COOL TUESDAY NIGHT IS ON TAP WITH MOST PLACES GETTING
DOWN INTO THE 50S. THROUGH THE MID WEEK PERIOD HIGH PRESSURE WEDGE
HOLDS ITS GROUND AT THE SURFACE. HOWEVER AS THE ANTICYCLONE JUST
ABOVE THE SURFACE WEAKENS THERE WILL BE AN INCREASINGLY ONSHORE FLOW
OF MOISTURE. FRICTIONAL CONVERGENCE ASIDE, THERE WON`T BE MUCH
FORCING FOR PRECIPITATION AND RAINFALL AMOUNTS WILL BE QUITE LIGHT,
AND MAYBE HARD-PRESSED TO MAKE MUCH INLAND PROGRESS. THIS MAY CHANGE
LATE THURSDAY THROUGH SATURDAY AS THE LOW LEVEL FLOW BECOMES A BIT
MORE CONVERGENT AND SOME WEAK ISENTROPIC UPGLIDE DEVELOPS ATOP THE
PERSISTENT WEDGE.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...SURFACE LOW PRESSURE CENTERED ABOUT 60-80 MILES
SOUTHEAST OF ILM WILL MOVE NORTHEASTWARD AND AWAY FROM THE AREA
TODAY. PATCHY LIGHT RAIN ALONG THE COAST SHOULD END OVER THE NEXT
FEW HOURS...WITH THE DENSE MID/HIGH CLOUDS TAKING AT LEAST A FEW
HOURS AFTER DAYBREAK TO CLEAR OUT. BENEATH THESE HIGHER CLOUDS IS A
REGION OF LOWER STRATUS/STRATOCUMULUS HUGGING THE COAST. EARLIER IFR
CEILINGS AT ILM HAVE RISEN ABOVE 1000 FEET BUT OBSERVATIONS SHOW
800-900 FOOT CEILINGS AT ISO...DPL AND OAJ. IF IFR CONDITIONS OCCUR
EARLY THIS MORNING ILM SHOULD BE THE PLACE. OTHERWISE VFR CONDITIONS
SHOULD DEVELOP BY DAYBREAK FOR ALL AREAS AS DRIER AIR BUILDS IN
OFFSHORE BREEZES.

EXTENDED OUTLOOK...GUSTY NORTHEAST WINDS WILL BECOME NORTHWEST
AND DECREASE SUN AS LOW PRESSURE MOVES NE FURTHER AWAY FROM THE
TERMINALS. OTHERWISE VFR SUN THROUGH WED WITH A CHANCE OF A SHOWER
WITH A COLD FRONT ON MONDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM SATURDAY...ADVISORY HAS BEEN EXTENDED UNTIL NOON
SUNDAY FOR SEA HEIGHT RECOVERY TIME. WIND SPEEDS 20-25 KT WITH
WINDS NE BACKING TO N LATE. SIGNIFICANT SEAS 4 TO 7 FT. WIND
DRIVEN WAVES WITH DOMINANT PERIODS IN THE 4 TO 5 SECOND PERIOD
RANGE TO DOMINATE THE SIG SEAS. ISOLATED THUNDERSTORMS ON THE 0-20
NM WATERS. THE OCEAN IS HAZARDOUS TONIGHT AND EARLY SUNDAY AND
NAVIGATION OFFSHORE IS DISCOURAGED.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...WINDS AND SEAS WILL BE ON THE DECREASE
THROUGHOUT THE DAY SUNDAY AS LOW PRESSURE MOVES QUICKLY AWAY TO THE
NORTHEAST. A NORTHWESTERLY FLOW WILL BACK TO THE SOUTHWEST BY DAYS
END AS A FRONT APPROACHES FROM THE NORTHWEST. WIND SPEEDS WILL BE IN
A 10-15 KNOT RANGE. MONDAY WILL FEATURE THE WIND SHIFT AS THE FRONT
PUSHES ACROSS THE WATERS LATE IN THE DAY. EXPECT A NORTHERLY
COMPONENT TO BE IN PLACE BY 0000 UTC TUESDAY THEN VEERING TO
NORTHEAST BY TUESDAY AM. SPEEDS WILL INCREASE FROM NEAR TEN KNOTS
LATE MONDAY TO 15-20 KNOTS TUESDAY. THERE WILL BE SOME RESIDUAL 3-5
FOOT SEAS EARLY SUNDAY DROPPING TO 2-3 FEET UNTIL EARLY TUESDAY WHEN
THEY WILL INCREASE SLIGHTLY.

LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...HIGH PRESSURE WEDGE TO REMAIN IN PLACE FIRMLY
THROUGH THE PERIOD IN A PATTERN MORE TYPICAL OF LATER INTO THE COOL
SEASON. THE GRADIENT ITSELF WILL BE STRONG ENOUGH TO YIELD SMALL
CRAFT ADVISORY WINDS, BUT SEAS WILL ALSO BE ADVISORY-WORTHY AREA
WIDE (AMZ254 MAY HAVE A BIT OF TROUBLE DUE TO WAVE SHADOW OFF CAPE
FEAR). NOT ONLY WILL THE ADVISORY BE IN EFFECT FOR THE DURATION OF
THE PERIOD BUT ALSO LIKELY BEYOND AS THE WEDGE SHOWS LITTLE SIGN OF
WEAKENING OR MOVING HEADING INTO THE WEEKEND.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SUNDAY FOR AMZ250-252-254-
     256.

&&

$$

NEAR TERM...COLBY
SHORT TERM...SHK
LONG TERM...BACON
AVIATION...TRA




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