Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 260601
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1259 AM EST MON JAN 26 2015

.SYNOPSIS...
A QUICK MOVING AREA OF LOW PRESSURE WILL DIVE SOUTHEAST...REACHING
THE OHIO VALLEY THIS EVENING. THE LOW WILL MOVE ACROSS NC EARLY
MONDAY...BEFORE REDEVELOPING OFF THE COAST OF THE VA NC BORDER.
THE LOW WILL BOMB AS IT MOVES VERY SLOWLY UP THE EAST COAST OF THE
U.S. MONDAY THRU WED. FOR THE AREA WATERS...HIGH PRESSURE WILL BUILD
IN FROM THE WEST MONDAY NIGHT THROUGH WEDNESDAY...BEFORE MOVING
OFFSHORE THURSDAY. A COLD FRONT WILL PUSH THROUGH THE CAROLINAS
EARLY FRIDAY FOLLOWED BY HIGH PRESSURE FOR THE UPCOMING WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1015 PM SUNDAY...LATEST SATELLITE 11-3.9 MICRON IR IMAGERY
SHOWS CLEAR SKIES GIVING WAY TO MID-LEVEL CLOUDINESS FROM THE
WEST. TRENDS AND LATEST MODEL RUNS INDICATE THESE CLOUDS WILL
OVERSPREAD THE FA DURING THE PRE-DAWN MONDAY HRS. AS A
RESULT...THE CURRENT DECENT RADIATIONAL COOLING CONDITIONS WILL
END BY MIDNIGHT. THE SFC PG TO PARTIALLY TIGHTEN AHEAD OF THE
APPROACHING CLIPPER LOW AND THUS THE CURRENT DECOUPLED WINDS
ACROSS THE FA WILL BEGIN TO ACT UP...S-SW WINDS INCREASING TO 3
TO 6 MPH. TEMPS AFTER MIDNIGHT WILL EITHER HOLD STEADY OR EXHIBIT
A SLOW CLIMB.

THE CLIPPER LOW WILL WEAKEN AND TRANSFER ITS ENERGY TO INTENSIFYING
LOW OFF VA-NC COAST DURING MON. THIS LOW IS FORECAST TO BOMB AS IT
MOVES UP THE EAST COAST THRU WED ACCOMPANIED WITH EXTREMELY NASTY
WINTER WX ACROSS THE NE STATES. FOR THE ILM CWA THO...MOISTURE
WITH THIS CLIPPER WILL MOVE ACROSS THE FA IN THE FORM OF MID AND
UPPER LEVEL CLOUDS...MAINLY AFTER MIDNIGHT. SEE THE 1ST PARAGRAPH.
PCPN CHANCES FROM THIS DYNAMIC MID-LEVEL S/W WILL BE ON THE LOW
CHANCE SIDE...POSSIBLY OCCURRING AROUND DAYBREAK MON...AND MAINLY
ALONG AND WEST OF THE I-95 CORRIDOR. PCPN WILL BE JUST LIQUID
LIGHT RAIN.

PREVIOUS DISCUSSION.....................................
AS OF 3 PM SUNDAY...AWAY FROM THE BEACHES IT HAS BEEN AN OUTSTANDING
DAY ACROSS THE EASTERN CAROLINAS WITH BRIGHT SUNSHINE AND
TEMPERATURES IN THE MID-UPPER 50S. THE BEACHES THEMSELVES HAVE A
VERY CHILLY SEABREEZE BLOWING ONSHORE WITH AIR TEMPERATURES STUCK
NEAR 50.

A WEAK RIDGE OF HIGH PRESSURE PUSHED OFF THE COAST EARLY THIS
AFTERNOON...AND THE GRADIENT WILL TIGHTEN OVERNIGHT IN ADVANCE OF A
CLIPPER-TYPE LOW MOVING SOUTHEASTWARD FROM ILLINOIS. THIS LOW WON`T
REACH THE AREA UNTIL TOMORROW...BUT THE FIRST WAVE OF CLOUDS AND
DYNAMICALLY-SUPPORTED LIFT SHOULD ARRIVE LATE TONIGHT. ISENTROPIC
MODEL FIELDS SHOW WEAK LIFT DEVELOPING ALONG THE 290K-295K THETA
SURFACES BY 12Z (7 AM) MONDAY MORNING...BUT MOISTURE IS STILL
VERTICALLY THIN WITH MULTIPLE DRY LAYERS INTERFERING WITH PRECIP
GENERATION. THE APPROACH OF THE COLD UPPER LOW WILL GRADUALLY
STEEPEN MID LEVEL LAPSE RATES...AND BY 12Z THERMAL PROFILES SHOULD
APPROACH THE MOIST ADIABATIC LAPSE RATE THROUGH THE 900-500 MB
LAYER. THIS COULD LEAD TO ISOLATED SHOWERS DEVELOPING...ESPECIALLY
INLAND. I WILL MAINTAIN SLIGHT CHANCES FOR SHOWERS INLAND VERY LATE
TONIGHT.

TEMPERATURES SHOULD DROP LIKE A ROCK THIS EVENING AND MAY BE WITHIN
A FEW DEGREES OF FORECAST LOWS BY 10 PM. INCREASING WINDS LATE THIS
EVENING AT THE TOP OF THE SHALLOW BOUNDARY LAYER SHOULD INDUCE
ENOUGH TURBULENCE TO PREVENT THE RADIATIONAL INVERSION FROM BECOMING
MUCH STRONGER. CLOUDS INCREASING LATE TONIGHT MAY EVEN CAUSE A
RISING TREND IN TEMPERATURES. FORECAST LOWS RANGE FROM 35-40 ACROSS
SE NORTH CAROLINA...TO AROUND 40 ACROSS NE SOUTH CAROLINA.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...REGION WILL REMAIN UNDER THE CONTROL OF SLOW
MOVING 5H TROUGH FOR THE MAJORITY OF THE PERIOD. A SERIES OF
SHORTWAVES WILL MOVE AROUND THE BASE OF THE TROUGH MON AND CONTINUE
TO AFFECT THE REGION TUE AS TROUGH AXIS IS SLOW TO LIFT NORTHEAST.
COLD POOL ALOFT MON WILL GENERATE CONSIDERABLE CLOUD COVER WITH
POTENTIAL FOR AFTERNOON SHOWERS. WHILE POSSIBLE THE LIKELIHOOD OF
SMALL HAIL FROM ANY DEVELOPING SHOWERS SEEMS TO BE DIMINISHING. THE
STRENGTH OF THE COLD POOL ALOFT IN GUIDANCE HAS SHOWN A WEAKENING
TREND WITH TEMPS ALOFT WARMING OVER THE LAST DAY OR SO. COVERAGE OF
SHOWERS WILL BE LIMITED DUE TO THE LACK OF DEEP MOISTURE. PLAN TO
CONTINUE WITH LOW CHANCE POP GIVEN THE MID LEVEL LAPSE RATES.
DESPITE CLOUD COVER AND POTENTIAL SHOWERS HIGHS MON WILL RUN ABOVE
CLIMO...HELPED BY WESTERLY LOW LEVEL FLOW.

CLOUDS AND SHOWERS MAY LINGER INTO MON EVENING BUT INCREASING
SUBSIDENCE AND MID LEVEL DRYING IN THE WAKE OF EXITING 5H TROUGH AND
ASSOCIATED SHORTWAVES BRINGS AN END TO ANY ACTIVITY BEFORE MIDNIGHT.
COLD ADVECTION BEGINS MON NIGHT AS LOW PRESSURE STARTS TO RAPIDLY
DEEPEN OFF THE MID ATLANTIC AND NEW ENGLAND COASTS. 850 TEMPS DROP 5
TO 7 DEGREES C OVERNIGHT...ENDING UP AROUND -5C BY DAYBREAK TUE.
ONLY STRONG MIXING WILL KEEP LOWS WITHIN A FEW DEGREES OF CLIMO.

TUE AND TUE NIGHT WILL BE COLD WITH TEMPS BELOW TO WELL BELOW CLIMO.
SHORTWAVE APPROACHING FROM THE NORTHWEST SHOULD INCREASE AFTERNOON
CLOUD COVER BUT MID LEVEL LAPSE RATES ARE WEAKER THAN MON AND THE
MID LEVELS ARE DRIER. THEREFORE WHILE CLOUDS MAY INCREASE DO NOT SEE
SHOWERS DEVELOPING.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...AIR MASS WILL BEGIN TO MODIFY AS HIGH
PRESSURE BUILDS OVER THE CAROLINAS WED INTO THURS. THE DEEP COLD
NW FLOW ON WED WILL WEAKEN AS RIDGE ALIGNS UP THE EAST COAST AND
CENTER OF HIGH SETTLES OVER THE REGION BY WED NIGHT. THE MID TO
UPPER LEVEL FLOW WILL BECOME MORE ZONAL BY THURS WITH H5 HEIGHTS
RISING ABOUT 25 DEM. OVERALL WARMING OF THE ATMOSPHERE WILL OCCUR
BY THURS WITH 850 TEMPS UP FROM NEAR -8C WED MORNING UP TO 5C BY
THURS. THE VERY DRY AIR MASS IN PLACE WILL BEGIN TO MODIFY ONCE
THE RIDGE SHIFTS OFF SHORE ON THURS WITH MORE OF A WARMER W-SW
FLOW SETTING UP. FLOW REMAINS QUITE PROGRESSIVE THOUGH...AND THE
WARMER RETURN FLOW THURS AFTN WILL BE BRIEF AS NEXT COLD FRONT
CROSSES THE CAROLINAS BY FRI MORNING. TEMPS THURS SHOULD SPRING
BACK UP TO NORMAL OR ABOVE BUT WILL BE KNOCKED BACK DOWN A FEW
DEGREES BY THE WEEKEND AFTER COLD FRONT MOVES THROUGH ON FRI.
THERE WILL BE SOME MOISTURE RETURN IN SW RETURN FLOW ON THURS INTO
EARLY FRI AHEAD OF NEXT FRONT. INITIALLY LOOKS LIKE IT WILL COME
IN WITH THE MID TO UPPER LEVEL FLOW SO EXPECT INCREASING CLOUDS
THROUGH LATE THURS BUT BEST UPPER LEVEL SUPPORT WILL COME INTO
EARLY FRI MORNING. OVERALL MOISTURE WILL BE LACKING BUT WILL ADD
LOW END POPS MAINLY VERY EARLY FRI MORNING. ANOTHER SHOT OF COLD
AND DRY AIR WILL COME ON FRI AS HIGH PRESSURE BUILDS DOWN FROM
CANADA. DEEP NW-N FLOW ON FRI WILL BACK ON SATURDAY AS SHORTWAVE
APPROACHES. LOOKS LIKE SOME CLOUDS AND PCP MAY DEVELOP SAT AFTN AS
COASTAL TROUGH DEVELOPS WITH WEDGE OF HIGH PRESSURE INLAND. THIS
SHOULD CLEAR OUT BY SUNDAY AS HIGH PRESSURE BUILDS DOWN FORM THE
NORTH. ECMWF IS SLOWER AND FOCUSES POPS MORE ON SUNDAY. WILL KEEP
SILENT POPS FOR NOW AND WILL SEE WHAT THE NEXT MODEL RUNS BRING.

TEMPS WILL STILL RUN BELOW NORMAL ON WED REACHING NEAR 50 MOST
PLACES. WITH HIGH OVERHEAD WED NIGHT...CLEAR SKIES AND CALM WINDS
WILL ALLOW FOR IDEAL RADIATIONAL COOLING AND TEMPS BELOW FREEZING
MOST PLACES. TEMPS FRI WILL BE MORE SEASONAL WITH SUNSHINE BACK IN
THE FORECAST. SATURDAY SHOULD START OUT CLEAR AND COOL WITH SOME
INCREASING CLOUDS AND CHC OF PCP SAT AFTN INTO SAT EVE.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...EXPECT VFR TO PREVAIL THROUGH THE VALID PERIOD...WITH
CLOUDS INCREASING OVERNIGHT AND SHOWERS POSSIBLE ON MONDAY AS A
QUICKLY PROPAGATING SYSTEM MOVES THROUGH THE AREA.

WHILE ONE MODEL SUGGESTS MARGINAL MVFR FOG DEVELOPMENT AT THE INLAND
SITES...AM EXPECTING INCREASED BOUNDARY LAYER WINDS TO KEEP
DEVELOPMENT CHANCES LOW. THROUGH THE OVERNIGHT HOURS WILL SEE A
GRADUAL INCREASE OF MID TO HIGH LEVEL CLOUDS AHEAD OF THE NEXT
SYSTEM...WITH VARIABLE WINDS AROUND 5 KT. AFTER DAYBREAK...WINDS
THROUGHOUT THE DAY WILL VEER...BECOMING WESTERLY WITH SUSTAINED
WINDS AOB 10 KT BY MORNING AND THEN INCREASING EVEN MORE TO AOB 12
KT WITH GUSTS AROUND 20 KT INTO THE EARLY AFTERNOON HOURS.
ISOLATED TO SCATTERED SHOWERS ARE POSSIBLE...THUS HAVE INTRODUCED
VCSH ATTM. LOW CLOUDS MOVE IN AS WELL...AND COULD NOT RULE OUT A
BRIEF PERIOD OF MVFR DUE TO LOW CIGS IN THE AFTERNOON...BUT
CONFIDENCE IS LOW ATTM. INTO THE LATE EVENING HOURS CHANCES OF
PRECIPITATION WILL DIMINISH...AND WINDS WILL BECOME NORTHWEST...
WITH GUSTS UP TO AROUND 20 KT CONTINUING.

EXTENDED OUTLOOK...SLIGHT CHANCE OF -RA/MVFR CIGS MONDAY. VFR
WEDNESDAY THROUGH FRIDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 PM SUNDAY...WINDS AND SEAS ACROSS THE LOCAL WATERS
HAVE BASICALLY DIMINISH AND SUBSIDE TO THEIR LOWS OF THE NIGHT
RESPECTIVELY. HOWEVER...THIS IS JUST TEMPORARY. WILL BE LOOKING
FOR THE SFC PG TO BEGIN RE-TIGHTENING AFTER MIDNIGHT AHEAD OF THE
APPROACHING CLIPPER LOW. THUS...THE CURRENT WINDS AT 5 TO 10 KT...
WILL INCREASE TO 10 TO 20 KT BY DAYBREAK MON. THIS MAY BE A BIT ON
THE LOW SIDE GIVEN 41013 RECENT REPORT OF SW 18G23. BUT THEN
AGAIN...41013 IS SITUATED OVER SSTS IN THE MID 60S...WHEREAS THE ILM
COASTAL WATERS EXHIBIT SSTS IN THE LOW 50S...MAKING IT MORE
DIFFICULT FOR WAA WINDS ALOFT FROM MIXING DOWN TO THE OCEAN SFC.
SIGNIFICANT SEAS HAVE BOTTOMED OUT AROUND 2 FEET...BUT SHOULD
BUILD-SOME OVERNIGHT TO THE 2 TO 4 FOOT RANGE BY DAYBREAK MON. WIND
DRIVEN WAVES WILL DOMINATE THE SIG SEAS WITH DOMINANT PERIODS AROUND
6 SECONDS.

PREVIOUS DISCUSSION....................................
AS OF 3 PM SUNDAY...THE WEAK RIDGE OF HIGH PRESSURE PUSHED OFFSHORE
EARLY THIS AFTERNOON AND WILL MOVE FARTHER OFF THE CAROLINA COAST
TONIGHT. THE NEXT WEATHER SYSTEM IS LOCATED OVER SOUTHERN ILLINOIS
AND WILL MAKE A BEE-LINE FOR NORTH CAROLINA TOMORROW. UNTIL
THEN...A TIGHTENING PRESSURE GRADIENT BETWEEN THE DEPARTING RIDGE
AND THE APPROACHING LOW WILL CAUSE INCREASING SOUTHWEST WINDS
OVERNIGHT. THIS WILL BE MOST EVIDENT AWAY FROM SHORE WHERE WATER
TEMPERATURES ARE WARMER AND ATMOSPHERIC MIXING IS BETTER DEVELOPED.
WINDS 15-20 MILES OUT SHOULD INCREASE TO A SOLID 15 KNOTS...WHILE
NEARSHORE IN THE COOLER MORE STABLE ENVIRONMENT WINDS SHOULD REMAIN
CLOSER TO 10 KT. SEAS CURRENTLY 2-3 FT MAY BUILD TOWARD 4 FT 15-20
MILES FROM SHORE IN RESPONSE TO THE INCREASING WINDS LATE.

SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 300 PM SUNDAY...DEVELOPMENT AND INTENSIFICATION OF LOW
PRESSURE MOVING OFF TO THE NORTHEAST MON AND TUE WILL MAINTAIN
OFFSHORE FLOW THROUGH THE PERIOD. WINDS HAVE MORE OF A WESTERLY
COMPONENT MON WITH AN INCREASE IN SPEEDS EXPECTED MON NIGHT INTO TUE
AS WINDS VEER TO THE NORTHWEST. PINCHED GRADIENT AS THE LOW
INTENSIFIES SOUTHEAST OF NEW ENGLAND WILL PUSH SPEEDS OVER 20 KT MON
NIGHT BUT OFFSHORE TRAJECTORY WILL KEEP SEAS 2 TO 4 FT. REDUCTION IN
OFFSHORE FLOW TUE IS SHORT LIVED AS ANOTHER COLD SURGE ARRIVES TUE
NIGHT...ONCE AGAIN PUSHING SPEEDS CLOSE TO 20 KT OVERNIGHT. SEAS
WILL REMAIN 2 TO 4 FT.

LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...HIGH PRESSURE WILL MOVE CLOSER ON WED
REACHING OVER THE WATERS BY WED NIGHT. THEREFORE NW WINDS UP TO 20
KTS EARLY WED WILL DIMINISH THROUGH LATE WED INTO THURS AS HIGH
PRESSURE PASSES OVERHEAD. SEAS AROUND 2 TO 4 FT EARLY WED WILL
CONTINUE TO DROP THROUGH THURS MORNING DOWN TO LESS THAN 3 FT MOST
WATERS.

LIGHT NORTHERLY FLOW WED EVE WILL BECOME MORE VARIABLE BEFORE
SHIFTING AROUND TO THE SW AS NEXT SYSTEM APPROACHES THURS EVE. THESE
INCREASING SW WINDS WILL VEER AROUND THROUGH THURS NIGHT AS COLD
FRONT APPROACHES. SEAS WILL REACH UP TO 3 TO 5 FT THURS NIGHT INTO
FRI BUT AS WINDS BECOME MORE OFF SHORE AS FRONT APPROACHES AND MOVES
THROUGH...GREATEST SEAS WILL GET DISPLACED FURTHER OFF SHORE THURS
NIGHT INTO EARLY FRI. NW-N WINDS ON FRI WILL DIMINISH AS GRADIENT
RELAXES AS HIGH PRESSURE REACHES INTO THE WATERS FROM THE NORTH.
WINDS WILL VEER TO MORE N-NE THROUGH FRI NIGHT AS HIGH PRESSURE TO
THE NORTH MOVES TOWARD THE COAST.

&&

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

&&

$$

NEAR TERM...DCH/TRA
SHORT TERM...III
LONG TERM...RGZ
AVIATION...SGL/RJD





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