Area Forecast Discussion
Issued by NWS Wilmington, NC

Current Version | Previous Version | Graphics & Text | 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 300719
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
319 AM EDT SAT AUG 30 2014

.SYNOPSIS...
STRENGTHENING BERMUDA HIGH PRESSURE OFFSHORE WILL BRING WARM WEATHER
THROUGH THE LABOR DAY WEEKEND WITH A FEW AFTERNOON SHOWERS AND
THUNDERSTORMS POSSIBLE. A WEAK COLD FRONT WILL APPROACH FROM THE
NORTH LATE IN THE PERIOD BUT IS LIKELY TO STALL BEFORE REACHING
THE AREA. BERMUDA HIGH AND PIEDMONT TROUGH WILL REMAIN THE
DOMINANT FEATURES INTO NEXT WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...MID AND UPPER LEVEL HIGH PRESSURE WILL BE
ALMOST DIRECTLY OVERHEAD TODAY. THIS WILL KEEP THE FLOW OF TROPICAL
MOISTURE ORIGINATING FROM THE WESTERN GULF ROUTED UP THE MISSISSIPPI
RIVER VALLEY INTO THE GREAT LAKES WITH NO IMPACT THIS FAR EAST. AT
THE SURFACE A PESKY LITTLE BACKDOOR COLD FRONT APPEARS TO HAVE SUNK
AS FAR SOUTH AS NORTHERN PENDER AND BLADEN COUNTIES THIS MORNING.
THIS BOUNDARY MAY ACTUALLY LINGER ACROSS SOUTHEASTERN NORTH CAROLINA
FOR MUCH OF THE MORNING BEFORE RETURNING NORTH EARLY THIS
AFTERNOON...PUSHED BY A COMBINATION OF THE LOCAL SEABREEZE
CIRCULATION PLUS A SLOW VEERING OF THE SYNOPTIC WIND AS HIGH
PRESSURE MOVES FARTHER EAST OFF THE NEW ENGLAND COASTLINE.

ALTHOUGH THERE IS NO SYNOPTIC FORCING PRESENT TODAY...AN UNSTABLE
AIRMASS WILL DEVELOP WITH SURFACE-BASED CAPE RISING TO 1500 J/KG AT
THE COAST AND NEAR 1000 J/KG INLAND. ONLY ISOLATED SHOWERS ARE
EXPECTED...MAINLY EAST OF I-95. IN TERMS OF TIMING...THE BETTER
SHOWER CHANCES MAY ACTUALLY OCCUR DURING THE MORNING AND EARLY
AFTERNOON HOURS WITH DEEPER MIXING DURING THE AFTERNOON DRAGGING
DOWN DRY AIR FROM ALOFT AND DILUTING THE SURFACE-BASED INSTABILITY.
PLENTY OF DRY AIR ALOFT AND VERY WEAK WINDS THROUGHOUT THE
TROPOSPHERE FAVOR ONLY SMALL THUNDER CHANCES AND NO STORM-CELL
ORGANIZATION. HIGHS TODAY SHOULD RISE INTO THE LOWER 90S INLAND WITH
UPPER 80S NEAR THE COAST.

MOSTLY CLEAR TO PARTLY CLOUDY SKIES AND LIGHT WINDS WILL AGAIN FAVOR
AREAS OF LOW CLOUDS AND/OR FOG LATE TONIGHT. LOWS SHOULD FALL TO
NEAR 70.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...WEAKENING MID LEVEL RIDGE ON SUN WILL STILL BE
WORKING TO LIMIT AFTERNOON CONVECTION. FORECAST SOUNDINGS SHOW AN
ABUNDANCE OF MID LEVEL DRY AIR AND A WEAK SUBSIDENCE INVERSION.
ELONGATED BERMUDA HIGH WILL ENSURE PLENTY OF LOW LEVEL MOISTURE AND
WARMTH WITH THE WEAK GRADIENT ALLOWING SEA BREEZE DEVELOPMENT.
HOWEVER THE SEA BREEZE IS LIKELY TO BE THE ONLY FORCING MECHANISM
AND IT MAY NOT BE ENOUGH TO OVERCOME THE SUBSIDENCE. A WEAK PIEDMONT
TROUGH MAY DEVELOP IN THE AFTERNOON BUT IT PROBABLY WILL NOT BE OF
ENOUGH SIGNIFICANCE TO GENERATE CONVECTION.

CONTINUED DEEP SOUTHWEST FLOW MON COMBINED WITH WEAKENING MID LEVEL
RIDGE WILL LEAD TO AN INCREASE IN PRECIP CHANCES. PRECIPITABLE WATER
VALUES CLIMB TO 2 INCHES MON AFTERNOON WITH FORECAST SOUNDINGS
SHOWING NO EVIDENCE OF THE PREVIOUS DAYS INVERSION. WEAK SURFACE
GRADIENT WILL AGAIN ALLOW FOR SEA BREEZE DEVELOPMENT...WHICH SHOULD
BE MORE ACTIVE THAN ON SUN. PIEDMONT TROUGH WILL BE MUCH MORE
DEFINED AND SHOULD ALSO ACT AS A FOCUS FOR CONVECTION. WILL CONTINUE
TO CARRY AFTERNOON LOW CHC POP. TEMPERATURES WILL RUN ABOVE CLIMO
THROUGH THE PERIOD.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...BERMUDA HIGH AND PIEDMONT TROUGH WILL BE THE
DOMINANT SURFACE FEATURES WHILE ALOFT WEAK ELONGATED 5H RIDGE
EXTENDS ACROSS MUCH OF THE SOUTHERN CONUS. THIS PATTERN IS FAIRLY
TYPICAL OF SUMMER AND COMBINED WITH PRECIPITABLE WATER VALUES AROUND
2 INCHES...ALSO TYPICAL FOR THIS TIME OF YEAR...WILL KEEP PRECIP
CHANCES NEAR CLIMO THROUGH THE PERIOD...30 TO 40 PERCENT. LACK OF
ANY FORCING ALOFT WILL LEAVE THE SEA BREEZE AND PIEDMONT TROUGH AS
TRIGGERS FOR CONVECTION. OUTFLOW FROM STORMS AS WELL AS LINGERING
BOUNDARIES FROM PREVIOUS DAYS CONVECTION WILL ALSO PLAY POTENTIAL
ROLES IN CONVECTIVE INITIATION. LATE IN THE PERIOD A COLD FRONT MAY
DROP IN FROM THE NORTH BUT THE STRENGTH OF THIS FEATURE WHEN IT
ARRIVES...IF IT ARRIVES...IS QUESTIONABLE. TEMPERATURES WILL BE NEAR
TO ABOVE CLIMO THROUGH THE PERIOD.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z SATURDAY...EXPECT AREAS OF MVFR/IFR CIGS/VSBYS TO DEVELOP
AS LOW LEVEL MOISTURE HAS INCREASED THANKS TO ONSHORE FLOW
YESTERDAY. SREF PROBS CONTINUE TO INDICATE THE BEST CHANCES FOR IFR
WILL BE INLAND AT KLBT AND KFLO...LIKELY IN THE 09-12Z TIME FRAME.
HAVE ALSO ADDED TEMPO IFR FOR KCRE AS SOME FOG/STRATUS IS EXPECTED
HERE ONCE THE WINDS GO CALM. WILL MAINTAIN MVFR CONDITIONS AT
KILM/KMYR... THOUGH BRIEF PERIODS OF IFR AROUND DAYBREAK CANNOT BE
RULED OUT. ALL TAF SITES SHOULD IMPROVE TO VFR BY 13-14Z TODAY. THEN
VFR WILL PREVAIL THROUGH THE REST OF THE PERIOD WITH SOUTHEAST WINDS
AOB 10 KT...HIGHEST ALONG THE COAST. SLIGHT CHC OF ISOLATED SHRA
ALONG THE SEA BREEZE DOES NOT WARRANT A MENTION IN THE TAFS ATTM.

EXTENDED OUTLOOK...INCREASING CHANCES FOR AFTN SHOWERS/TSTMS MONDAY
THROUGH WEDNESDAY WITH BRIEF AND LOCALIZED PERIODS OF MVFR POSSIBLE.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM SATURDAY...A PESKY LITTLE BACKDOOR FRONT LOCATED NEAR
JACKSONVILLE NC MAY ACTUALLY SNEAK DOWN AS FAR SOUTH AS CAROLINA
BEACH BEFORE STALLING LATER THIS MORNING AND RETURNING NORTH THIS
AFTERNOON. IT`S A PRETTY INSIGNIFICANT FEATURE IN THE WEATHER-WORLD
BUT COULD TURN WIND DIRECTIONS EAST TO NORTHEASTERLY FOR A FEW
HOURS. OTHERWISE A LIGHT SOUTHEASTERLY WIND SHOULD PREVAIL THROUGH
THE DAY...ENHANCED BY THE AFTERNOON SEABREEZE.

ISOLATED SHOWERS OUT ACROSS THE OFFSHORE WATERS WILL MOVE TOWARD THE
COAST SHORTLY AFTER SUNRISE. RAINFALL COVERAGE SHOULD AVERAGE ONLY
10-20 PERCENT OF THE AREA...ALTHOUGH UNIDIRECTIONAL WIND THROUGH THE
LOWEST 6000 FEET OF THE ATMOSPHERE RAISES THE POTENTIAL THAT
WATERSPOUTS COULD DEVELOP EVEN IN A WEAK SHOWER CELL. SHOWER CHANCES
SHOULD DIMINISH RAPIDLY THIS AFTERNOON BEHIND THE DEVELOPING
SEABREEZE FRONT. WINDS WILL TURN MORE SOUTHERLY WITH TIME TONIGHT
WITH NO INCREASE IN WIND SPEED EXPECTED.

SEAS CURRENTLY AROUND 2 FEET MAY BUILD TO 3 FEET AWAY FROM SHORE AS
A SWELL SET PRODUCED BY THE BERMUDA HIGH ARRIVES AT THE COAST. NOAA
BUOY 41002 LOCATED ABOUT 200 MILES OFFSHORE STARTED PICKING UP THIS
SWELL ABOUT 6 PM YESTERDAY. THIS SOUTHEASTERLY 7 TO 8 SECOND SWELL
SHOULD BE OUR DOMINANT WAVE THROUGH TONIGHT.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...SURFACE GRADIENT WILL REMAIN WEAK THROUGH THE
PERIOD WITH ELONGATED BERMUDA HIGH OFF THE COAST. THIS WILL MAINTAIN
LIGHT SOUTH TO SOUTHWEST FLOW THROUGH MON NIGHT. SPEEDS WILL RUN
AROUND 10 KT OVERNIGHT WITH DIURNAL INCREASES TO A SOLID 15 KT EACH
DAY. SEAS WILL RUN 2 TO 3 FT THROUGH THE PERIOD.

LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...ELONGATED BERMUDA HIGH REMAINS IN PLACE TUE
AND WED WITH PIEDMONT TROUGH BECOMING A LITTLE MORE DEFINED. SLIGHT
INCREASE IN GRADIENT EACH AFTERNOON WILL INCREASE SOUTHWEST FLOW TO
A SOLID 15 KT INTO THE EARLY EVENING HOURS. OTHERWISE SOUTHWEST FLOW
WILL BE 10 KT OR LESS. SEAS RUN 2 TO 3 FT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.

&&

$$

NEAR TERM...TRA
SHORT TERM...III
LONG TERM...III
AVIATION...BJR/TRA






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