Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 191100
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
701 AM EDT FRI SEP 19 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE CAROLINAS FROM THE NORTH AS LOW
PRESSURE DEVELOPS OFF THE SOUTHEAST COAST AND MOVES NORTHWARD INTO
THE WEEKEND. A COLD FRONT WILL MOVE ACROSS THE AREA MONDAY NIGHT
FOLLOWED BY COOL AND DRY HIGH PRESSURE DURING THE MIDDLE OF NEXT
WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

HIGH PRESSURE AT THE SURFACE WILL PRESS DOWN FROM THE NORTH
THROUGH THE NEAR TERM AS A TROUGH OF LOW PRESSURE FORMS AND
SUBSTANTIALLY DEEPENS OVER THE FAR WESTERN ATLANTIC. GUIDANCE ALL
IN GOOD GENERAL AGREEMENT ON THIS SCENARIO...WHICH WILL ALLOW FOR
A GRADUALLY STRENGTHENING AND DEEPENING EASTERLY FLOW OVER THE
EASTERN CAROLINAS. CONTINUED RELATIVELY COOL NORTHEAST TO EASTERLY
FLOW WILL BRING SEASONAL TEMPERATURES TO THE AREA TODAY AND
TONIGHT...WITH HIGHS IN THE LOWER TO MID 80S...AND LOWS IN THE
LOWER TO MID 60S.

MODEL SOUNDINGS SHOW LOW LEVEL CONVERGENCE...STRONGEST AS ONE
APPROACHES THE COAST...WILL LEAD TO ISOLATED TO WIDELY SCATTERED
SHOWERS OR THUNDERSTORMS...ESPECIALLY THIS AFTERNOON AND
OVERNIGHT...MAINLY OVER OUR SC COUNTIES WHERE THE DEEPEST MOISTURE
IS.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...HIGH PRESSURE WILL BUILD DOWN THE COAST SAT
WHILE WEAK TROUGHING ALOFT CONTINUES. SURFACE LOW WILL START TO TAKE
SHAPE OFF THE EAST COAST OF FL. THIS LOW DEVELOPS ALONG THE REMAINS
OF A STALLED SURFACE BOUNDARY SO INITIALLY IT WILL NOT BE TROPICAL
IN NATURE BUT AS IT LIFTS NORTH-NORTHEAST IT MAY ACQUIRE SOME
TROPICAL CHARACTERISTICS. NHC CONTINUES TO ADVERTISE A 20% CHANCE OF
TROPICAL DEVELOPMENT THROUGH 5 DAYS...BUT EVEN IF THIS FEATURE
DEVELOPS INTO A FULL BLOWN TROPICAL SYSTEM IT WILL HAVE A LIMITED
AMOUNT OF TIME TO STRENGTHEN AND STEERING FLOW WOULD KEEP IT OFF THE
COAST.

ULTIMATE PATH OF THE LOW IS STILL IN QUESTION...WITH HOW CLOSE IT
PASSES OFF THE COAST THE MAIN CONCERN. DO NOT THINK ANY SIGNIFICANT
WINDS WILL BE REALIZED BUT IT COULD MAKE FOR A CLOUDY/SOGGY
SAT...ESPECIALLY ALONG THE IMMEDIATE COAST. OCCASIONAL GUSTS TO 20
MPH ALONG THE COAST ARE A POSSIBILITY. INLAND THERE WILL BE LESS OF
A PRECIP THREAT THOUGH ENHANCED NORTHEAST FLOW BETWEEN THE SURFACE
HIGH AND THE DEVELOPING LOW WOULD LIKELY MAINTAIN SOME LOWER CLOUDS
AND THE PINCH GRADIENT WILL CREATE BREEZY CONDITIONS. WILL CARRY LOW
CHC TO SLIGHT CHC POP ALONG THE COAST SAT INTO SAT NIGHT AND DRY
INLAND. NORTHEAST FLOW...CLOUDS...AND PRECIP WILL KEEP HIGHS BELOW
CLIMO BUT LINGERING CLOUD COVER AND MOISTURE OVERNIGHT WILL HOLD
LOWS ABOVE CLIMO.

EXITING SURFACE LOW AND MID LEVEL TROUGH IN PLACE LEADS TO
DEVELOPMENT OF DEEP WEST TO NORTHWEST FLOW SUN...DRYING THE REGION
OUT. PRECIPITABLE WATERS DROP ABOUT AN INCH SAT INTO SUN...FALLING
FROM AROUND 1.7 TO AROUND 0.7. THE RESULT WILL BE BEAUTIFUL DAY WITH
ABUNDANT SUNSHINE AND HIGHS IN THE MID 80S. DEVELOPMENT OF RETURN
FLOW AHEAD OF ADVANCING COLD FRONT WILL HELP KEEP LOWS ABOVE TO WELL
ABOVE CLIMO SUN NIGHT THOUGH SKIES SHOULD BE MOSTLY FREE OF CLOUDS.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 3 AM FRIDAY...MID LEVEL TROUGH DROPPING SOUTH FROM THE WESTERN
GREAT LAKES WILL PUSH A COLD FRONT ACROSS THE AREA MON. WHERE
PREVIOUS MEDIUM RANGE GUIDANCE HAD A DECENT AMOUNT OF MID LEVEL
MOISTURE THE LAST FEW RUNS HAVE SHOWN A STEADY DECREASE IN MOISTURE
ALOFT AND QPF. AT THIS POINT EVEN WITH IDEAL TIMING DURING PEAK
HEATING THINK CONVECTION IS GOING TO BE SPOTTY IN NATURE AND HAVE NO
PLANS TO CHANGE INHERITED SLIGHT CHC POP.

FRONT ENDS UP STALLED OFF THE COAST TUE WITH MODIFIED HIGH BUILDING
IN FROM THE PLAINS. MID LEVEL PATTERN OVER THE SOUTHEAST TRANSITIONS
TO PROGRESSIVE TUE INTO WED AS THE 5H TROUGH OVER SOUTHEAST CANADA
LIFTS NORTHEAST. MOISTURE ALONG THE STALLED FRONT MAY LEAD TO
COASTAL CLOUDS AND LIGHT PRECIP DURING THE DAY.

SOLUTIONS FOR MID TO LATE WEEK DIVERGE WITH SOME OF THE GUIDANCE
SHOWING A COLD FRONT PUSHING SOUTH ON WED AS REINFORCING HIGH BUILDS
IN. THIS WOULD KEEP THE REGION COOL AND DRY THROUGH THE END OF THE
PERIOD. THE OTHER SOLUTION INVOLVES A COASTAL TROUGH WITH A WEAKER
REINFORCING SURFACE HIGH. THE TROUGH AND ASSOCIATED MOISTURE ARE
MUCH CLOSER TO THE COAST WITH CLOUDS/PRECIP OVER MUCH OF THE
SOUTHEAST. ONLY PLAN MINIMAL CHANGES TO INHERITED FORECAST UNTIL MID
TO LATE WEEK DETAILS BECOME A LITTLE CLEARER.

&&

.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...STRONG WEDGE WILL CONTINUE THROUGH THE FORECAST PERIOD.
GRADIENT WILL BE QUITE STRONG...WITH EAST NORTHEAST WINDS ALONG THE
COAST GUSTING TO 20 KTS. THERE WILL BE SHOWERS ALONG THE PERIPHERY
OF THE WEDGE...AND THERE IS A POSSIBILITY OF CONVECTION ALONG THE
EXTREME WESTERN PORTION OF THE CWA...AS WELL AS THE COAST. COVERAGE
WILL BE QUITE LIMITED HOWEVER. WINDS WILL BE LIGHTER TONIGHT...BUT
WILL STAY ABOVE 7-8 KTS MOST OF THE NIGHT. A NOCTURNAL ONSHORE
SHOWER IS POSSIBLE AT THE MYRTLES NEAR THE END OF THE FORECAST
PERIOD.

EXTENDED OUTLOOK...CHANCE OF SHOWERS ALONG THE COAST SAT. GUSTY
NORTHEAST WINDS SAT WILL BECOME NORTHWEST ON SUN AS LOW PRESSURE
WELL OFFSHORE MOVES UP THE EAST COAST. VFR ON MON/TUE.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 6:15 AM FRIDAY...NO CHANGES TO THE FORECAST WITH THE LATEST
UPDATE. PREVIOUS DISCUSSION FOLLOWS:

NORTHEASTERLY WINDS WILL GRADUALLY STRENGTHEN OVER THE WATERS
TODAY AND TONIGHT AS HIGH PRESSURE PRESSES DOWN FROM THE NORTH AND
AS A TROUGH OF LOW PRESSURE FORMS AND SUBSTANTIALLY DEEPENS OVER
THE FAR WESTERN ATLANTIC. SEAS WILL GRADUALLY BUILD IN
RESPONSE...TO 4 TO 6 FT LATE THIS AFTERNOON OR TONIGHT OVER THE
WATERS. HAVE ISSUED A SMALL CRAFT ADVISORY FOR ALL WATERS AS
RESULT.

SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 AM FRIDAY...CONFIDENCE IS HIGH IN HIGH PRESSURE BUILDING
DOWN THE COAST SAT AS WEAK LOW PRESSURE DEVELOPS OFF THE EAST FL
COAST AND STARTS MOVING NORTH-NORTHEAST. HOWEVER...HAVE LOW
CONFIDENCE WITH RESPECT TO THE STRENGTH AND PATH THE LOW TAKES.
WHILE IT COULD ACQUIRE SOME TROPICAL CHARACTERISTICS AS IT LIFTS
NORTH CURRENT CONSENSUS IS THE LOW WILL REMAIN EAST OF THE WATERS.
PINCHED GRADIENT BETWEEN THE HIGH AND THE PASSING LOW WILL CAUSE
NORTHEAST FLOW IN THE 15 TO 20 KT RANGE SAT INTO SAT NIGHT.

WINDS BACK TO NORTHWEST AND THEN WEST-SOUTHWEST AS THE LOW EXITS OFF
TO THE NORTH ON SUN. GRADIENT WEAKENS AS THE LOW DEPARTS WITH WIND
SPEEDS DROPPING TO 10 TO 15 KT SUN AND UNDER 10 KT SUN NIGHT. 3 TO 5
FT SEAS SAT WILL SUBSIDE TO 2 TO 3 FT BY SUN AFTERNOON AS WINDS
BECOME OFFSHORE AND WEAKEN. IF THE LOW ENDS UP A LITTLE CLOSER TO
THE COAST LATE SAT SCA CONDITIONS MAY DEVELOP.

LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 AM THURSDAY...SOUTHWEST FLOW OVER THE WATERS MON WILL BECOME
OFFSHORE MON NIGHT IN THE WAKE OF AN EXITING COLD FRONT. AHEAD OF
AND IMMEDIATELY BEHIND THE FRONT WINDS WILL BE AROUND 10 KT. WINDS
VEER TO NORTHEAST LATE MON NIGHT THEN INCREASE TO 15 TO 20 KT TUE
AND TUE NIGHT. SEAS 2 TO 3 FT MON INTO TUE WILL BUILD TO 3 TO 5 BY
THE END OF THE PERIOD. HEADLINES MAY BE REQUIRED LATE IN THE PERIOD
DEPENDING ON THE STRENGTH AND DURATION OF THE SURGE.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 AM EDT
     SATURDAY FOR AMZ254-256.

     SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EDT
     SATURDAY FOR AMZ250-252.

&&

$$

SYNOPSIS...III
NEAR TERM...REK
SHORT TERM...III
LONG TERM...III
AVIATION...43
MARINE...REK/III







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