Area Forecast Discussion Issued by NWS Wilmington, NC
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 160551
AFDILM
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
151 AM EDT THU MAY 16 2013
.SYNOPSIS...
WARM TEMPERATURES WILL CONTINUE THROUGH EARLY NEXT WEEK AS HIGH
PRESSURE PUSHES OFFSHORE. THERE IS A SMALL RISK FOR MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS BEGINNING FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
-- Changed Discussion --
AS OF 1:45 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. RELEVANT PORTION OF PREVIOUS DISCUSSION FROM THIS
AFTERNOON FOLLOWS:
EXPECT CLEAR SKIES THROUGH TONIGHT. MID TO UPPER RIDGE HOLDS
OVER THE SOUTHEAST THROUGH TONIGHT MAINTAINING DRY CONDITIONS WITH
PLENTY OF SUBSIDENCE. SOUTHWEST FLOW WILL CONTINUE AS LOW PRESSURE
SYSTEM PASSES ACROSS THE NORTHEAST WITH TROUGH RUNNING DOWN
THROUGH INLAND CAROLINAS AND HIGH PRESSURE HOLDING OFF SHORE.
EXPECT WINDS TO REMAIN UP AS 5 TO 10 MPH THROUGH THE NIGHT IN
A TIGHTENED GRADIENT FLOW. WINDS WILL HELP KEEP A FLOW OF WARM
AND MOIST AIR INTO THE AREA WITH DEWPOINT TEMPS RISING UP CLOSE TO
60 F BY MORNING WITH OVERNIGHT LOWS HOLDING ABOVE 60 DEGREES.-- End Changed Discussion --
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...WARM ATLANTIC RIDGING WILL DOMINATE THE
PERIOD. A PIEDMONT TROUGH WILL REMAIN IN PLACE. A BACKDOOR COLD
FRONT WILL STRUGGLE TO MAKE SOUTHWARD PROGRESS AS IT DRIFTS ACROSS
VIRGINIA THU AND THU NIGHT AND THEN INTO NORTH CAROLINA FRI AND FRI
NIGHT. AT THIS TIME THE FRONT SHOULD GET HUNG UP N OF OUR FORECAST
AREA...PERHAPS GETTING CLOSE TO THE ONSLOW-PENDER COUNTY LINE BY SAT
MORNING AS IT BECOMES INCREASINGLY ILL-DEFINED.
IN TERMS OF HOW THIS WILL IMPACT OUR SENSIBLE WEATHER...IT WILL
REMAIN WARM THROUGH THE PERIOD. HIGH TEMPS ARE EXPECTED TO BE
SIMILAR TO THIS AFTERNOON...REACHING WELL UP INTO THE 80S BOTH DAYS.
A FEW SPOTS WILL LIKELY AGAIN TOUCH 90 DEGREES...ESPECIALLY ACROSS
PORTIONS OF THE PEE DEE ON THU. THE SEABREEZE WILL BE PINNED
RELATIVELY CLOSE TO THE COAST GIVEN THE DEEP WESTERLY FLOW. THUS...
EVEN THE BEACHES WILL REACH THE LOWER TO PERHAPS MID 80S WITH THE
EXCEPTION OF LOCATIONS ACROSS SOUTHERN NEW HANOVER AND COASTAL
BRUNSWICK COUNTIES WHERE MARINE INFLUENCES WILL LIKELY KEEP HIGHS
CLOSER TO 80 DEGREES. NIGHTTIME TEMPS WILL ALSO BE ABOVE NORMAL...
MID AND UPPER 60S ARE EXPECTED TO BE COMMON.
THIS SUMMERTIME PATTERN WILL NOT BE ESPECIALLY CONDUCIVE FOR SHOWERS
AND THUNDERSTORMS GIVEN THE DRY AIR BELOW 15 KFT AND THE LACK OF
SIGNIFICANT TRIGGERS ALOFT. THE DEEP AND SUBSIDENT WESTERLY FLOW
WILL ALSO BE A LIMITING FACTOR. CONFIDENT THAT DRY WEATHER WILL
PERSIST THROUGH THU NIGHT. ON FRI...THE DRY AIR SHRINKS...CONFINED
TO THE LOWEST 5-6 KFT OF THE COLUMN. THUS...GIVEN THE AFOREMENTIONED
SURFACE FEATURES...CAN NOT RULE OUT THE DEVELOPMENT OF ISOLATED TO
PERHAPS SCATTERED SHOWERS AND THUNDERSTORMS. THE COVERAGE MAY BE
GREATEST ALONG THE SEABREEZE AND THE PIEDMONT TROUGH WHERE THERE
WILL BE SOME WEAK CONVERGENCE. WANING CONVECTION TO OUR N...
ASSOCIATED WITH THE BACKDOOR COLD FRONT...MAY APPROACH THE AREA
FRI NIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...PERSISTENT SUMMER-LIKE PATTERN EXPECTED
THROUGH THE LONG TERM AS BERMUDA HIGH PRESSURE SITS ANCHORED
OFFSHORE. WHILE THIS LEAVES WARM S/SW RETURN FLOW ACROSS THE
CAROLINAS...WITH TEMPS RISING TO NEAR/ABOVE NORMAL EACH
DAY...THERE IS A POTENTIAL FLY-IN-THE-OINTMENT WITH A BACK DOOR
COLD FRONT STALLING VERY NEAR THE CWA. AT THIS TIME...BELIEVE THE
FRONT WILL REMAIN JUST TO THE NORTH OF THE LOCAL AREA THANKS TO
RETURN FLOW IMPEDING ITS SOUTHERN MOTION...AND THE FACT THAT WE
ARE MOVING BEYOND THE CLIMATOLOGICALLY FAVORED PERIOD FOR BACK
DOOR COLD FRONTS TO SINK THIS FAR SOUTH. HOWEVER...A SLOW MOVING
VORT EMBEDDED WITHIN THE AMPLIFYING MID-LEVEL FLOW WILL MOVE OVER-
TOP THE STALLED BOUNDARY...INCREASING RAIN/CONVECTION CHANCES
ALONG THE FRONT. FOR THIS REASON THERE IS SOME UNCERTAINTY IN POP
AND TEMPS...SINCE IF THE FRONT SAGS INTO THE CWA MAX TEMPS WILL
LOWER...AND POP WILL INCREASE. WITH BEST SUPPORT FOR FRONT
REMAINING NORTH...WILL KEEP INHERITED LOW-CHC POP FOR DIURNAL
CONVECTION WITH TEMPS IN THE LOW/MID 80S. LATE IN THE PERIOD...5H
HEIGHTS REBUILD ACROSS THE SOUTHEAST...BRINGING A SLIGHT WARMING
TREND AND DECREASING CHANCES FOR CONVECTION.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
AS OF 06Z...VFR CONDITIONS AT ALL TERMS WILL PREVAIL DURING THIS TAF
PERIOD. SOUTHWEST WINDS 5-10 KTS WILL CONTINUE THROUGH THE OVERNIGHT
HOURS...BECOMING 10-15 KTS DURING THE DAY WITH GUSTS OF 20 KTS
POSSIBLE IN THE AFTN. OTHER THAN SOME SCT CIRRUS AFTER 18Z...DO NOT
EXPECT MUCH IN THE WAY OF CLOUD COVER. SOUTHWEST WINDS WILL DIMINISH
AFTER 00Z BUT REMAIN 5-10 KTS INTO THE EVENING HOURS. MID/HIGH
CLOUDS WILL INCREASE NEAR THE END OF THE PERIOD WITH A SHORTWAVE TO
OUR WEST.
EXTENDED OUTLOOK...CHANCE OF AFTN SHOWERS/TSTMS FRIDAY THROUGH
MONDAY...OTHERWISE VFR.-- End Changed Discussion --
&&
.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 1:45 AM THURSDAY...NO CHANGES TO THE FORECAST WITH THE
LATEST UPDATE. PREVIOUS DISCUSSION FOLLOWS:
SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH 6 AM THIS MORNING.
WNA SHOWS PEAK IN SEAS AROUND MIDNIGHT WITH A STEADY DECREASE
THEREAFTER AS GRADIENT RELAXES A BIT WITH A CONTINUED SW TO W FLOW
OF 15 TO 20 KTS THROUGH EARLY THIS MORNING.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...BERMUDA HIGH PRESSURE WILL DOMINATE THROUGH
THE PERIOD. THE PIEDMONT TROUGH IN CONJUNCTION WITH THIS RIDGE WILL
HELP KEEP SOME GRADIENT ACROSS THE WATERS. A WEAKENING BACKDOOR COLD
FRONT WILL DRIFT SOUTHWARD FRI AND FRI NIGHT...BUT THE FRONT IS
EXPECTED TO REMAIN TO OUR N THROUGH SAT MORNING. SW WINDS WILL
CONTINUE THROUGH THE PERIOD. WINDS SHOULD BE A LITTLE HIGHER ON THU
GIVEN THE SLIGHTLY TIGHTER PRESSURE GRADIENT AS COMPARED TO FRI.
WILL FORECAST 15 TO 20 KT THU AND 10 TO 15 KT ON FRI. EXPECT 3 TO 4
FT SEAS ON THU TO SUBSIDE ABOUT A FOOT FOR FRI.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 3 PM WEDNESDAY...SUMMERTIME PATTERN DURING THE EXTENDED
WITH HIGH PRESSURE ANCHORED OFFSHORE PUMPING S/SW RETURN FLOW
ACROSS THE WATERS. WHILE A BACK DOOR COLD FRONT WILL BE TRYING TO
SAG SOUTH INTO THE NORTHERN WATERS AT THE START OF THE
PERIOD...ATTM DO NOT EXPECT ANY VEERING OF WINDS EVEN ACROSS THE
NORTHERN EDGE OF AMZ250...BUT WILL HAVE TO MONITOR THIS AS THE
WEEKEND APPROACHES. WHILE THE FRONT STAYS NORTH...S/SW WINDS WILL
PERSIST THROUGH THE PERIOD...AT SPEEDS OF AROUND 10
KTS...INCREASING TO 10-15 KTS ON MONDAY. SEAS OF 2-3 FT WILL BE
COMMON DURING THE WKND...GROWING TO 2-4 FT MONDAY THANKS TO THE
SLIGHTLY INCREASED WIND SPEEDS.-- End Changed Discussion --
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
AMZ250-252-254-256.-- End Changed Discussion --
&&
$$
NEAR TERM...REK/RGZ
SHORT TERM...RJD
LONG TERM...JDW
AVIATION...BJR
MARINE...REK/RJD/JDW/RGZ