Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 312034
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
334 PM EST SAT JAN 31 2015

.SYNOPSIS...
MORE SEASONABLE AIR WILL ARRIVE TOMORROW ALONG WITH A GRADUAL
INCREASE IN MOISTURE. RAINFALL WILL SPREAD ACROSS THE REGION
SUNDAY NIGHT INTO MONDAY AHEAD OF COLD FRONT. UNSETTLED WEATHER IS
EXPECTED LATE IN THE WEEK WITH LOW PRESSURE POSSIBLY FORMING OFF
THE COAST ALONG A COLD FRONT THAT MOVES THROUGH ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 3 PM SATURDAY...FAIR AND COOL EVENING WEATHER IN STORE FOR
NE SC AND SE NC AS THE HEART OF A MODIFIED ARCTIC AIR MASS SETTLES
OVER THE AREA THEN SLIPS OFFSHORE INTO EARLY SUNDAY. INFILTRATION
OF CIRRUS LATE TONIGHT AND WEAK RETURN WIND FLOW WILL LIKELY SERVE
TO LEVEL OFF OR SIGNIFICANTLY DECELERATE TEMPERATURE FALLS INTO
THE PRE-DAWN HOURS. MAINLY CLEAR SKIES THIS EVENING AND LIGHT WIND
ON THE OTHER HAND WILL PROMPT RAPID DROPS IN TEMPERATURES...WITH
SUB-FREEZING READINGS LIKELY BEFORE MIDNIGHT IN MANY LOCATIONS
AWAY FROM BEACHES AND THE ICWW CORRIDOR. THUS LOOK FOR MINIMUMS IN
MANY SPOTS POTENTIALLY TO OCCUR AROUND OR JUST AFTER MIDNIGHT
BEFORE LEVELING OFF INTO THE WEE HOURS OF SUNDAY...AS H5-H6 CLOUDS
THICKEN AND LIGHT S-SW WINDS PREVAIL.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...RETURN FLOW GETS UNDERWAY ON SUNDAY ALBEIT
PERHAPS SLOWER THAN PREVIOUSLY THOUGHT AS IT MAY BE LATER IN THE
DAY. MOST OF THE RETURN FLOW WILL GO TO INCREASING CLOUDS RATHER
THAN ACTUAL RAIN CHANCES WHICH SHOULD HOLD OFF UNTIL NIGHTTIME.
WARMER AIR MOVING INTO THE REGION WILL ALSO BRING ABOUT SOME WELCOME
SEASONABLE HIGH TEMPERATURES. AS THE RAINFALL CHANCES RAMP UP IN THE
STRENGTHENING WE MAY SEE TEMPERATURES NEARLY FLAT OR EVEN RISING
OVER SUNDAY NIGHT WITH LOW TEMPERATURES FAIRLY CLOSE TO SEASONABLE
HIGHS AND THE NIGHT WILL GROW INCREASINGLY BREEZY AS THE LOW LEVEL
JET REALLY RAMPS UP IN STRENGTH. SIMILARLY MONDAY WILL BE QUITE
BREEZY WITH SHOWERS THAT WILL BE OF MODERATE INTENSITY. ALL TOLD
SOME AREAS COULD NET A HALF INCH OF PRECIP. MONDAY MAY FEATURE A
SECOND PERIOD OF NON-DIURNAL TEMPERATURE CURVE AS THE MIDDAY FROPA
LEADS TO AFTERNOON FALLING TEMPERATURES. BACK TO REALITY MONDAY
NIGHT WITH TEMPERATURES NEAR OR BELOW THEIR SEASONABLE NORMS.


&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...UNCERTAINTY REMAINS PROMINENT DURING THE
PERIOD CONCERNING THE EVOLUTION OF SOUTHERN STREAM SYSTEM NEXT WEEK.
WHILE CONFIDENCE IN THE SOUTHERN STREAM FEATURE DEVELOPING IS QUITE
HIGH THE EXTENT OF ITS INTERACTION WITH A NORTHERN STREAM SHORTWAVE
MID TO LATE WEEK REMAINS UNCLEAR. LATEST GFS/CMC CONTINUE TO SHOW
INTERACTION OF THESE 2 FEATURES WITH UNSETTLED WEATHER ACROSS THE
SOUTHEAST THU AS THE LOW MOVES UP THE COAST AND THEN FRI AS THE 5H
TROUGH MOVES OVERHEAD. IN ADDITION THIS SOLUTION HAS SUPPORT FROM A
LITTLE MORE THAN HALF OF THE GFS ENSEMBLE MEMBERS. ON THE OTHER HAND
THE ECMWF PAINTS A MUCH DRIER PICTURE. IT HAS LIMITED INTERACTION
BETWEEN THE NORTHERN AND SOUTHERN STREAM SYSTEMS AND MOVES THE 5H
FEATURE AND THE SURFACE LOW ACROSS THE FL PENINSULA. IT IS WORTH
NOTING THAT WITH THE LAST SYSTEM...THE NORTHEAST BLIZZARD EARLIER
THIS WEEK...THERE WAS DISAGREEMENT BETWEEN THE GUIDANCE AND AT THE 5
DAY MARK THE CMC ENDED UP BEING PRETTY CLOSE.

NOT PLANNING MUCH IN THE WAY OF CHANGES FOR NOW GIVEN THE LARGE
AMOUNT OF UNCERTAINTY LATE IN THE PERIOD. UNTIL THE NORTHERN STREAM
SHORTWAVE IS ASSESSED BY THE UPPER AIR NETWORK GUIDANCE WILL LIKELY
CONTINUE TO STRUGGLE WITH THE TIMING...STRENGTH...AND TRACK OF THE
SYSTEM. EITHER WAY TEMPERATURES ARE GOING TO BE GENERALLY AT OR
BELOW CLIMO THROUGH THE PERIOD WITH HIGHS POTENTIALLY WELL BELOW
CLIMO MID TO LATE WEEK.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 18Z...HIGH CONFIDENCE CONTINUES FOR VFR THROUGH THE VALID TAF
PERIOD AS HIGH PRESSURE ACROSS THE AREA TODAY GRADUALLY PUSHES
OFFSHORE TONIGHT.

NEARLY CLEAR SKIES AND WEST-NORTHWESTERLY WINDS AOB 12 KTS WILL
GRADUALLY BECOME WEST-SOUTHWEST LATER THIS AFTERNOON. INTO THE
EVENING HOURS...HIGH CLOUDS WILL CONTINUE TO GRADUALLY INCREASE IN
OPACITY AS TIME-HEIGHT ANALYSIS AND FCST SOUNDINGS ILLUSTRATE...JUST
AHEAD OF THE NEXT APPROACHING SYSTEM. FEW/SCT HIGH CLOUD COVERAGE
EXPECTED LATER TODAY AND TONIGHT WITH BKN/OVC COVERAGE OVERNIGHT
INTO SUNDAY. WINDS WILL BECOME LIGHT AND VARIABLE TONIGHT AND
PERSIST THROUGH INTO SUNDAY MORNING...BECOMING SOUTHEASTERLY AOB 8
KTS INTO SUNDAY AFTERNOON.

EXTENDED AVIATION OUTLOOK...SHOWERS/MVFR LIKELY LATE SUN
THROUGH MON MORNING...THEN BECOMING VFR AGAIN THROUGH TUE. POSSIBLE
RAIN WED.


&&

.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 3 PM SATURDAY...A VASTLY IMPROVING MARINE ENVIRONMENT INDEED
MATEYS...AS SURFACE HIGH PRESSURE PARKS OVER THE WATERS AND WINDS
DIE OUT TO 10 KT OR LESS OVERNIGHT. THE BULK OF WAVE ENERGY HAS
BEEN LINKED WITH WINDS SO AS WINDS TAIL OFF...SEA HEIGHT WILL AND
PRESENTLY ARE SUBSIDING. 2-4 FOOT SEAS LATE THIS AFTERNOON WILL
FALL TO 2-3 FT THIS EVENING TO 1.5-2 FT INTO FIRST LIGHT SUNDAY
WITH LIGHT WIND. THIS WILL LIKELY ALLOW E WAVES OF 1-1.5 FT EVERY
9-10 SECONDS TO BECOME THE DOMINANT WAVE ACTION IN GENTLE ROLLING
SWELL. NO TSTMS OR RESTRICTIONS TO VISIBILITY ARE EXPECTED THROUGH
TONIGHT.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...VERY UNSETTLED FOR ALL BUT THE VERY START OF
THE PERIOD. THIS RELATIVE CALM COMES THROUGH MIDDAY SUNDAY AS HIGH
PRESSURE INITIALLY JUST OFFSHORE MOVES A BIT FURTHER OUT TO SEA.
THIS ALLOWS FOR A BROAD SWATH OF SWRLY RETURN FLOW TO SET UP ALL
ALONG THE EAST COAST. SUNDAY NIGHT INTO MONDAY WARM AND MOIST AIR
WILL STREAM INTO THE SOUTHEAST IN THIS RETURN FLOW REGIME. MEANWHILE
AN UPPER DISTURBANCE AND SURFACE COLD FRONT APPROACH FROM THE
NORTHWEST. A SMALL CRAFT ADVISORY IS EXPECTED FOR BOTH WIND AND
SEAS...EASILY. THE MAIN QUESTION IS WHETHER OR NOT GALES WILL OCCUR
AND BE FREQUENT ENOUGH THAT A GALE WARNING WILL BE NEEDED. AT THIS
TIME A GALE WATCH COULD BE HOISTED BUT AFTER COLLAB WITH NEIGHBORING
WFOS HAVE ELECTED TO HOLD OFF FOR NOW. THE TWO MAIN ISSUES THAT MAY
PRECLUDE GALES ARE: 1.THE STRONGER LOW LEVEL WIND FIELDS ON THE WRF
MAY BE OVERDONE AND 2. THE COOL SSTS WILL REALLY INHIBIT VERTICAL
MIXING IN THIS OTHERWISE WARM AIRMASS. SOME PRETTY STRONG WINDS MAY
BE LURKING JUST OFF THE DECK BUT MAY HAVE TROUBLE REACHING THE
SURFACE...WITH ANY REGULARITY. REGARDLESS IT LOOKS LIKE HAZARDOUS
CONDITIONS PERSIST AND A MIDDAY OR EARLY PM FROPA WILL ADD A
STEEPENING ELEMENT OF CONFUSION TO WAVE FACES DUE TO ABRUPT WIND
SHIFT.

LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...SURFACE HIGH BUILDING IN FROM THE WEST TUE
WILL MOVE OVERHEAD AND OFFSHORE TUE NIGHT AND WED. PINCHED GRADIENT
INITIALLY WILL HAVE NORTHEAST FLOW IN THE 15 TO 20 KT RANGE BUT
GRADIENT IS QUICK TO RELAX AND BY MIDDAY NORTHEAST FLOW WILL BE 10
KT OR LESS. LIGHT AND VARIABLE WINDS TUE NIGHT BECOME SOUTHERLY ON
WED. EARLY THU WINDS VEER TO NORTHERLY AS COLD FRONT MOVES ACROSS
THE WATERS. STILL SOME UNCERTAINTY LATE IN THE PERIOD BUT NEARLY ALL
OF THE SOLUTIONS DO SHOW MODERATE TO STRONG NORTHERLY FLOW
DEVELOPING THU INTO THU NIGHT. HEADLINES MAY BE REQUIRED LATE IN THE
PERIOD. LIGHT AND VARIABLE WINDS WILL KEEP SEAS 2 TO 3 FT TUE AND
WED WITH AN INCREASE EXPECTED LATE IN RESPONSE TO INCREASED WIND
SPEEDS.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM MONDAY TO 1 AM EST TUESDAY FOR
     AMZ250-252-254-256.

&&

$$
SYNOPSIS...MBB
NEAR TERM...MJC
SHORT TERM...MBB
LONG TERM...III
AVIATION...SGL





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