Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 280539
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1239 AM EST SUN DEC 28 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLIP FARTHER OFFSHORE ALLOWING MILD AIR AND
INCREASING MOISTURE TO OVERSPREAD THE AREA. RAIN CHANCES WILL PEAK
TONIGHT AND MONDAY AS A COLD FRONT MOVES SOUTH ACROSS THE CAROLINAS.
SEVERAL WAVES ALONG THIS FRONT MAY BRING PATCHY LIGHT RAIN THROUGH
TUESDAY. CLEARING AND COOLER WEDNESDAY AND NEW YEARS DAY AS HIGH
PRESSURE BUILDS INTO THE AREA. MOISTURE AND TEMPERATURES WILL
INCREASE LATE IN THE WEEK AS A STORM SYSTEM DEVELOPS WEST OF THE
REGION...BRINGING POTENTIALLY A WET WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1239 AM SUNDAY...RADAR DETECTING LIGHT HIGH ALTITUDE ECHOES
OVERSPREADING CENTRAL SC MOVING ENE IN THE WSW FLOW ALOFT...AND
MOST OF THE RETURNS REMAIN VIRGA WITH A FEW TRACE REPORTS IN THE
BUCKETS EMERGING ACROSS CENTRAL SC INTERIOR. THICKENING CLOUDS
LOCALLY ANTICIPATED AND A SLIGHT CHANCE OF -RA FAR INTERIOR ZONES
OF NE SC/SE NC AS THE VIRGA SLOWLY OVERCOMES AN OVERALL DRY COLUMN
STILL RESIDING HERE. NO SIGNIFICANT CHANGES AND TEMPERATURES
SHOULD HOLD IN THE 40S FOR THE MOST PART AS CLOUD COVER BECOMES A
CEILING...IMPLYING MINIMUM TEMPERATURES AT DAYBREAK WILL BE WITHIN
A DEGREE OR 2 OF CURRENT READINGS MOST LOCALS.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...NO LESS THAN 4 DISTINCT FEATURES WORKING
TOGETHER WILL CREATE AN UNSETTLED SHORT TERM PERIOD. HIGH PRESSURE
OFFSHORE WILL CONTINUE TO PUSH TO THE EAST INTO EARLY NEXT
WEEK...DRIVEN BY A SLOWLY DEAMPLIFYING MID-LEVEL RIDGE OFF THE EAST
COAST. THIS LEAVES DEEP SW FLOW AND MOIST ADVECTION ACROSS THE
SOUTHEAST. EMBEDDED WITHIN THIS DEEP SW FLOW...2 SHORTWAVES...A WEAK
ONE SUNDAY MORNING...AND A STRONGER IMPULSE MONDAY MORNING...WILL
TRAVERSE OVERHEAD THE AREA. THE FORMER WILL BE ACCOMPANIED BY SOME
VERY LIGHT RAINFALL SUNDAY MORNING...FOCUSED MOSTLY ACROSS INLAND
ZONES. A BREAK IN PRECIP IS ANTICIPATED SUNDAY AFTN/EVE THANKS TO
SUBSIDENCE AND DRYING BEHIND THIS FEATURE...BEFORE RAIN RE-DEVELOPS
LATE SUNDAY NIGHT. THE SECOND /STRONGER/ SHORTWAVE WILL BE
ACCOMPANIED BY A SURFACE REFLECTION AND WIDESPREAD RAINFALL IS
EXPECTED DURING MONDAY AS THE LOW PRESSURE MOVES ACROSS AND DRAGS A
COLD FRONT BEHIND IT. AGAIN...TOTAL QPF LOOKS PRETTY LOW BUT AN
AVERAGE OF ONE-QUARTER TO AS MUCH AS ONE-HALF INCH OF RAINFALL IS
POSSIBLE MONDAY. THE COLD FRONT WILL SLOW OFFSHORE MONDAY
NIGHT...KEEPING UNSETTLED AND DRIZZLY CONDITIONS GOING THROUGH THE
END OF THE PERIOD.

TEMPS SUNDAY WILL WARM WELL INTO THE 60S THANKS TO WAA AND AFTN
INSOLATION...AND LOWS WILL STRUGGLE TO FALL MUCH DUE TO CLOUDS AND
THE CONTINUED WARM SW FLOW. EXPECT LOWS SUNDAY NIGHT TO DROP ONLY
INTO THE MID 50S - VALUES MORE TYPICAL OF LATE-DECEMBER HIGHS. HIGHS
MONDAY WILL STILL BE WARM AHEAD OF THE COLD FRONT...BUT A FEW
DEGREES COOLER THAN SUNDAY. A BIGGER DROP IN TEMPS IS FORECAST FOR
MONDAY NIGHT THANKS TO DEVELOPING CAA BEHIND THE FRONT...AND LOWS
WILL FALL INTO THE LOW/MID 40S...COOLEST FAR NW.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...TUESDAY`S WEATHER MAP WILL FEATURE AN
UNUSUALLY LARGE AREA OF HIGH PRESSURE COVERING JUST ABOUT THE
ENTIRE NATION, IT`S CENTER OVER MONTANA. AT IT`S CORE IT IS A VERY
CHILLY AIRMASS BUT WITH THE CAROLINAS ONLY ON THE SOUTHEASTERN
PERIPHERY TEMPERATURES WILL ONLY BE A LITTLE BIT BELOW CLIMO. OVER
THE NEXT SEVERAL DAYS THIS AIRMASS WILL BLEED SLOWLY SOUTHWARD
INTO THE PLAINS. CONFLUENT MID AND UPPER LEVEL FLOW OVER THE
EASTERN U.S. WILL ALSO DRAW A RIDGE AXIS INTO THE MIDATLANTIC FROM
THE PARENT HIGH. THIS SETS UP VERY LITTLE IN THE WAY OF THERMAL
ADVECTION ACROSS THE SOUTHEAST AND MID ATLANTIC AS LOW LEVEL
THICKNESSES AND ISOTHERMS ALIGN WITH THE ZONAL FLOW ALOFT. RAD
COOLING TUESDAY NIGHT WILL HELP TO MAKE WEDNESDAY COOLER THAN
TUESDAY AS FAIRLY SHALLOW MIXING OCCURS EACH DAY AND FAIRLY GOOD
RADIATIONAL COOLING OCCURS EACH NIGHT. THINGS BECOME QUITE
PROGRESSIVE FRIDAY AND SATURDAY WITH RETURN FLOW SETTING UP AND
MOISTURE RETURNING ALONG WITH IT. CLOUDS AND TEMPERATURES SHOULD
BOTH BE ON THE RISE. THE GFS HAS COASTAL TROUGHINESS AS WELL THAT
WOULD IMPLY SOME MINOR RAIN CHANCES, BUT THIS FEATURE IS LARGELY
ABSENT IN THE ECMWF AND CANADIAN. WILL CAP POPS AT SLIGHT
CHANCE/20S LATE IN THE PERIOD.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 06Z...VFR WILL PREVAIL OVERNIGHT WITH TEMPO PERIODS OF MVFR
CIGS/VSBYS POSSIBLE IN THE EARLY MORNING HOURS. AS MID/HIGH CLOUDS
INCREASE AND CIGS LOWER...BR APPEARS TO BE LESS OF A THREAT DESPITE
THE CALM SFC WINDS. HOWEVER...FCST SOUNDINGS STILL HINT AT SCT MVFR
STRATOCU DEVELOPING TOWARD DAYBREAK AND LINGERING THROUGH MUCH OF
THE DAY. AN UPPER DISTURBANCE WILL MOVE ACROSS THE CENTRAL CAROLINAS
THIS MORNING...PERHAPS BRINGING SOME -RA TO THE INLAND TERMINALS.
AVIATION IMPACTS WOULD BE LIMITED EVEN IF ANY PRECIP FALLS AT KFLO
OR KLBT.

EXPECT SOUTHWEST WINDS AOB 10 KT DURING THE DAY. THIS WIND
TRAJECTORY...BRINGING WARM MOIST AIR OVER COOL SHELF WATERS...WOULD
FAVOR SEA FOG AND STRATUS DEVELOPMENT AFTER 00Z MON. GUIDANCE AND
SREF OUTPUT ARE ALREADY PICKING UP ON REDUCED CIGS/VSBYS DURING THE
EVENING HOURS. KMYR/KCRE WOULD LIKELY BE THE FIRST SITES AFFECTED AS
POTENTIAL SEA FOG SPREADS UP THE S.C. COAST. THIS COULD RESULT IN
IFR/LIFR CIGS/VSBYS BEFORE THE END OF THE PERIOD. FOR NOW...WILL
ADVERTISE MVFR VSBYS WITH SCT IFR/LIFR STRATUS...MAINLY DUE TO
UNCERTAINTIES IN THE TIMING/ONSET OF DENSE FOG.

EXTENDED OUTLOOK...RAIN WITH MVFR/IFR CIGS/VSBYS ON MON. MVFR/IFR
CIGS WILL PERSIST INTO TUE. VFR ON WED. MVFR CIGS POSSIBLE MAINLY AT
THE COASTAL SITES ON THU.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1239 AM SUNDAY...SEAS 4.3 FEET AT 16 SECONDS AT FRYING PAN
BUOY WITH LIGHT WIND SO MOSTLY SWELL IMPACTING THE WATERS FROM A
PREVIOUS NORTH ATLANTIC STORM. INSHORE HEIGHTS 2 - 2.5 FEET AT
BOTTOM FRICTION CONSUMES A PORTION OF THE INCOMING WAVE ENERGY.
WINDS INSHORE SHOULD HOLD AT N-NE AT 10 KT OR LESS OVERNIGHT AND
OFFSHORE SE 10 KT AS A WEAK INVERTED COASTAL TROUGH/LOW MIGRATES
NNE ALONG OUR COAST.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 PM SATURDAY...OFFSHORE HIGH PRESSURE WILL DRIVE SW RETURN
FLOW INTO THE AREA SUNDAY AND THE FIRST PART OF MONDAY...BEFORE A
COLD FRONT DROPS SOUTH ACROSS THE WATERS MONDAY EVENING. THIS
CREATES TWO DISTINCT WIND REGIMES DURING THE SHORT TERM...SW AROUND
10 KTS AHEAD OF THE COLD FRONT...QUICKLY BECOMING NE AT 10-15 KTS
MONDAY NIGHT. WAVE HEIGHTS WILL BE 2-4 FT THROUGH THE PERIOD...WITH
THE HIGHEST SEAS OCCURRING SUNDAY AFTN AND AGAIN MONDAY NIGHT BEHIND
THE COLD FRONT.

LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 300 PM SATURDAY...SPRAWLING HIGH PRESSURE COVERING MOST OF
THE NATION THROUGH THE PERIOD. INITIALLY CENTERED OVER MONTANA, IT
WILL BOTH BLEED SOUTH AND EXTEND A RIDGE AXIS EASTWARD AS TIME
WEARS ON. THIS KEEPS WIND MORE OR LESS OUT OF THE NORTH TUESDAY
THROUGH WEDNESDAY. UNCERTAINTY CRAWLS INTO THE FORECAST ON
THURSDAY AS THE HIGH MAY STILL BE BRINGING A NORTHERLY/OFFSHORE
FLOW OR A SURFACE TROUGH MAY DEVELOP OFFSHORE AND TURN WINDS MORE
EASTERLY.

&&

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

&&

$$

NEAR TERM...MJC
SHORT TERM...JDW
LONG TERM...MBB
AVIATION...8/BR






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