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

000
FXUS62 KILM 241934
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
334 PM EDT SUN AUG 24 2014

.SYNOPSIS...
HIGH PRESSURE WILL EXPAND SOUTH ACROSS THE AREA THROUGH
WEDNESDAY...BRINGING A PERIOD OF COOL AND DRY WEATHER. TROPICAL
STORM CRISTOBAL MAY BECOME A HURRICANE IN THE NEXT FEW DAYS AS IT
PASSES A FEW HUNDRED MILES EAST OF THE CAROLINAS. A WARMING TREND WILL
DEVELOP LATE IN THE WEEK. A BACKDOOR FRONT MAY APPROACH BY NEXT
WEEKEND...BRINGING A RISK FOR SHOWERS AND THUNDERSTORMS.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SUNDAY...COOL BUT BEAUTIFUL LATE SUMMER AFTERNOON
COMING TO AN END...LEAVING WHAT WILL BE ONE OF THE COOLER NIGHTS
THIS AREA HAS SEEN IN QUITE SOME TIME.

COLD FRONT CONTINUES TO SAG WELL SOUTH OF THE AREA...AND HAS PUSHED
TO NEARLY THE FLORIDA STATE LINE TODAY. DRIVING THIS BOUNDARY IS A
STRONG RIDGE OF HIGH PRESSURE OF CANADIAN ORIGIN...WITH THE CENTER
OF THIS HIGH ACTUALLY WELL NORTH OF WINNIPEG, CANADA IN THE NORTH
CENTRAL PART OF THE COUNTRY. THIS HIGH IS RIDGING INTO NEW ENGLAND
AND THEN DOWN THE EASTERN SEABOARD...WITH ABNORMALLY COOL AND DRY
AIR FOR LATE AUGUST FILTERING INTO THE REGION. THIS AIR MASS IS VERY
FALL-LIKE...AND DEWPOINTS HAVE FALLEN INTO THE LOW AND MID 60S
AREA-WIDE TODAY. THIS DRY AIR HAS LIMITED TOTAL INSTABILITY...AND
ALTHOUGH HIGH-RES GUIDANCE CONTINUES TO SUGGEST THE POTENTIAL FOR
ISOLATED SEA-BREEZE SHOWERS THROUGH THIS EVE...THE CHANCE FOR THAT
IS WANING...AND EVEN DIURNAL CU IS HAVING TROUBLE GAINING MUCH
AGITATION. STILL CONTINUED JUST VERY SCHC ALONG THE SC PORTION OF
THE SEA BREEZE FOR THE NEXT FEW HOURS. IF A SHOWER DOES DEVELOP IT
WILL ERODE QUICKLY AFTER DARK...AS WILL THE MAJORITY OF THE CLOUD
COVER.

NE WINDS WILL REMAIN ELEVATED TONIGHT...LIKELY STAYING 5-10 MPH INTO
MONDAY MORNING. THESE WINDS WILL CONTINUE TO ADVECT COOL/DRY
AIR...THUS DRIVING MINS WELL BELOW 70...WITH LOWER 60S ENCOMPASSING
THE NORTHERN HALF OR 2/3 OF THE CWA. WHILE ELEVATED WINDS TEND TO
LIMIT OVERALL COOLING...NE WINDS HAVE A TENDENCY TO COOL THE AREA
MORE THAN WOULD TYPICALLY BE EXPECTED...ESPECIALLY ACROSS THE CAPE
FEAR REGION. FOR THIS REASON HAVE FORECAST THE LOWEST TEMPS IN THE
NE ZONES TONIGHT...AND WILMINGTON MAY SEE ITS COOLEST NIGHT SINCE
EARLY JUNE.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE FORECAST AREA WILL REMAIN IN THE GRIP OF
AN UNSEASONABLE NE FLOW AS HIGH PRESSURE CENTERED ACROSS THE
NORTHEAST U.S. RIDGES SOUTH...WITH ITS AXIS REMAINING TO THE WEST OF
OUR FORECAST AREA. AT THE SAME TIME...SLOW STRENGTHENING OF THE VERY
SLOW MOVING TROPICAL STORM ACROSS THE BAHAMAS IS EXPECTED. THIS WILL
SERVE TO PROLONG THE RATHER TIGHT PRESSURE GRADIENT BETWEEN THESE
TWO SYSTEMS.

AS THESE NE WINDS PERSIST...THEY WILL SERVE TO PILE UP WATER ON THE
IMMEDIATE COAST. THIS IN COMBINATION WITH THE NEW MOON WILL INCREASE
THE RISK FOR MINOR BEACH EROSION FOR THOSE BEACHES EXPOSED TO A NE
FETCH AND MINOR COASTAL FLOODING DURING THE NIGHTTIME HIGH TIDE...
BOTH AT THE BEACHES AND ALONG THE LOWER CAPE FEAR RIVER. OTHER
HAZARDS WILL INCLUDE A STRONG LONG SHORE CURRENT...MODERATE TO
PERHAPS STRONG RIP CURRENTS AND HIGHER THAN NORMAL...ROUGH SURF.

TEMPS WILL BE COOL IN THIS BREEZY NE FLOW REGIME. HIGHS WILL BE
IN THE LOWER TO MID 80S...WITH TUE PERHAPS SLIGHTLY COOLER THAN
MON. LOWS WILL BE IN THE LOWER TO MID 60S WITH PERHAPS UPPER 60S
AT THE BEACHES. WIND SPEEDS ON MON WILL BE UP TO 10 TO 20 MPH WITH
HIGHER GUSTS...ESPECIALLY AT THE BEACHES.

OFFSHORE SHOWERS ARE EXPECTED TO REMAIN THERE FOR MUCH OF THE
PERIOD. TRAJECTORIES WILL AT TIMES BRING THE SHOWERS VERY NEAR THE
BEACHES...BUT GIVEN THE DRYNESS OF THE COLUMN...EXPECT THESE SHOWERS
TO LARGELY ERODE BEFORE MOVING ONSHORE.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...THE MID LEVEL PATTERN WILL SHOW TYPICAL LATE
SUMMER LETHARGY THROUGH THE PERIOD AS RIDGING WILL BE THE CENTRAL
THEME.

THE AXIS OF THE RIDGE MOVES FROM THE MISSISSIPPI VALLEY TO OFF THE
PENINSULA OF FLORIDA BY THE END OF THE PERIOD. AT THE SURFACE...WEAK
HIGH PRESSURE WILL PREVAIL AS WELL AND AS THE MID LEVEL RIDGE
REPOSITIONS...A RELATIVELY WEAK BACKDOOR FRONT WILL MOVE ACROSS
FRIDAY. THIS WILL SERVE TO ENHANCE THE POPS BOTH FRIDAY AND
SATURDAY. HOWEVER MOISTURE AND FORCING REMAIN RELATIVELY WEAK AND
SLIGHT CHANCE FRIDAY TO LOW CHANCE SATURDAY WILL SUFFICE FOR NOW.
THERE IS ALSO SLIGHT CHANCE POPS FOR WEDNESDAY AND THURSDAY ALONG
THE COASTAL AREAS.

THE COOL REFRESHING AIRMASS WILL BE A THING OF THE PAST AS
TEMPERATURES WEDNESDAY THROUGH FRIDAY WILL BE AT OR JUST ABOVE
CLIMATOLOGY. FOR NEXT WEEKEND...A SLIGHT DROP IN TEMPERATURES IS
SEEN AS THE BACKDOOR FRONT MOVES ACROSS BUT JUST A COUPLE OF
DEGREES.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...CIGS 3-5K EXPECTED AT THE TERMINALS THIS AFTN.
MID/LOW LEVEL MOISTURE COMBINED WITH SURFACE HEATING...WEAK LIFT
AND A WEAK UPPER IMPULSE COULD PRODUCE ISOLATED SHRA NEAR SOUTHERN
COASTAL TERMINALS THIS AFTERNOON...BUT HAVE OPTED TO LEAVE ANY
MENTION OUT OF TAFS DUE TO ISOLATED NATURE. WINDS WILL BE NE 10-15
KT WITH GUSTS TO 20 KT...OCCASIONALLY HIGHER. CIGS WILL SCATTER
OUT AT THE COASTAL TERMINALS TONIGHT.

WIND GUSTS DECREASE AROUND 00Z AS DOES SHRA POTENTIAL. VFR CONTINUES
THE REMAINDER OF THE TAF VALID PERIOD WITH SCT MVFR LEVEL CLOUDS AND
NE WINDS 5-10 KT.

EXTENDED OUTLOOK...VFR THROUGH THE PERIOD. A SLIGHT CHANCE COASTAL
SHOWERS THROUGH THURS. ISOLATED TSRA FRIDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM SUNDAY...PINCHING NE GRADIENT EAST OF A RIDGE OF HIGH
PRESSURE EXPANDING DOWN THE COAST IS CAUSING DETERIORATING MARINE
CONDITIONS TODAY. WINDS ARE SLOWLY BUT STEADILY RISING OUT OF THE
NE...WITH SPEEDS OF 15-20 KTS COMMON ACROSS THE WATERS...WITH SOME
GUSTS APPROACHING 30 KTS DEVELOPING OVER THE NORTHERN WATERS AND
OUTSIDE OF 20 NM. AS THE HIGH PRESSURE STRENGTHENS TONIGHT...THE
GRADIENT WILL TIGHTEN FURTHER...AIDED BY THE DISTANT BUT
STRENGTHENING TROPICAL STORM CRISTOBAL NEAR THE BAHAMAS. THIS WILL
CAUSE WIDESPREAD 15-25 KT NE WINDS THROUGH THE PERIOD...WITH SEAS
BUILDING TO 5-8 FT.

WAVE HEIGHTS WILL BE DRIVEN ALMOST ENTIRELY BY A NE WIND CHOP
TONIGHT. HOWEVER...LONGER PERIOD SWELL ASSOCIATED WITH TROPICAL
STORM CRISTOBAL IS FORECAST TO BEGIN TO ENTER THE SPECTRUM TONIGHT.
ONLY NOTICEABLE LONG-SWELL PRESENTLY EXISTS AT 41004 /EDISTO BUOY/
WHICH IS OBSERVING A LOW-AMPLITUDE 13 SEC SWELL. EXPECT THIS TO
GRADUALLY LIFT NE INTO THE LOCAL WATERS...BUT HAVE ONLY MINIMAL
CONTRIBUTION TO THE SIGNIFICANT SEAS UNTIL MONDAY.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...THE PRESSURE DIFFERENCE BETWEEN HIGH PRESSURE
TO THE NORTH AND A SLOWLY DEVELOPING TROPICAL STORM ACROSS THE
BAHAMAS WILL KEEP A TIGHT PRESSURE GRADIENT ACROSS THE WATERS. A
SMALL CRAFT ADVISORY REMAINS IN EFFECT. WINDS WILL COMMONLY BE
SUSTAINED AT 20 TO 25 KT. THE LONG NE FETCH WILL KEEP SEAS IN THE 4
TO 7 FT RANGE WITH AT LEAST 8 FT SEAS BEYOND 20 NM. A 10 TO 12
SECOND SE SWELL IS EXPECTED TO SLOWLY BUILD THROUGH THE PERIOD.

LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...CONFIDENCE CONTINUES TO BUILD THAT THE ONLY
IMPACTS FROM CRISTOBAL WILL BE THE SWELL COMPONENT ADDED TO THE WAVE
SPECTRUM. THE LATEST WAVEWATCH HURRICANE BULLETIN FOR FRYING PAN
SHOALS SHOWS 7-8 FEET DEVELOPING OR PERSISTING WEDNESDAY THROUGH
EARLY THURSDAY WITH A GOOD PORTION OF THIS BEING THE WIND WAVE
COMPONENT. THIS MAKES SENSE AS THE GFS IS NOT DEVELOPING THE SYSTEM
APPRECIABLY. FOR THE 0-20 MILE COASTAL WATERS 4-6 FEET WEDNESDAY AND
EARLY THURSDAY SHOULD SUFFICE. BY FRIDAY A WEAK PRESSURE PATTERN
YIELDS LIGHT WINDS AND SEAS. FOR THE WINDS WEDNESDAY AND
THURSDAY...A NORTHEASTERLY FLOW OF 10-15 KNOTS WEDNESDAY DROPS TO
SINGLE DIGITS THURSDAY.

&&

.TIDES/COASTAL FLOODING...
AS OF 300 PM SUNDAY...RIDGE OF HIGH PRESSURE EXPANDING DOWN THE
COAST IS DRIVING A PINCHED GRADIENT...AND FORCING A LONG PERIOD OF
GUSTY NE WINDS LOCALLY. THESE WINDS ARE FORCING WATER TO "PILE UP"
NEAR THE COASTLINE...AS NOTED BY TIDAL ANOMALIES OF 1 TO 2 FEET AT
THE LOCAL BEACHES. THIS FORCING COMBINED WITH ASTRONOMICAL HIGH
TIDES DUE TO THE APPROACH OF THE NEW MOON (NEW MOON IS
MONDAY)...WILL CAUSE HIGH TIDE LEVELS THIS EVENING TO APPROACH OR
SLIGHTLY EXCEED MINOR FLOOD THRESHOLDS ON THE EAST FACING BEACHES
NORTH OF CAPE FEAR. HIGH TIDE IS AROUND 730 PM AT WRIGHTSVILLE
BEACH...AND A COASTAL FLOOD ADVISORY HAS BEEN ISSUED...VALID FROM
6PM TO 9PM. THE EAST FACING BEACHES OF SC WILL FARE SLIGHTLY
BETTER DUE TO THE COASTLINE ORIENTATION WITH RESPECT TO WIND
DIRECTION...AND THUS SHOULD STAY BELOW MINOR FLOOD THRESHOLDS
TONIGHT.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY FROM 6 PM TO 9 PM EDT THIS EVENING FOR
     NCZ106-108.

MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT TUESDAY FOR AMZ250-252-254-
     256.

&&

$$
NEAR TERM...JDW
SHORT TERM...RJD
LONG TERM...SHK
AVIATION...JDW/MRR
TIDES/COASTAL FLOODING...JDW




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