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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KILM 150232
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
1032 PM EDT MON APR 14 2014

.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA TUESDAY...WITH INCREASING
CHANCES FOR SHOWERS AND THUNDERSTORMS TONIGHT AND TUESDAY. HIGH
PRESSURE WILL MOVE INTO THE AREA WEDNESDAY AND CONTROL AREA WEATHER
INTO FRIDAY BEFORE CONDITIONS DETERIORATE IN ADVANCE OF A COLD FRONT
THAT WILL MOVE INTO THE AREA AND STALL INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
-- Changed Discussion --
AS OF 1015 PM MONDAY...THE REMAINDER OF THE EVENING POPS WILL
CONTINUE TO TAKE INTO ACCOUNT THE CURRENT PCPN PAINTED BY MOSAIC
RADARS...ALONG WITH ITS IMMEDIATE FUTURE MOVEMENT. FOR POPS AFTER
MIDNIGHT THROUGH DAYBREAK...HAVE FOLLOWED MORE CLOSELY TO THE HRRR
OUTPUT THAT MIMICS PROGGED REFLECTIVITY ACROSS THE ILM CWA. IN
ADDITION...FOLLOWED THE LATEST SREF OVERNIGHT PROBABILITIES FOR
MEASURABLE RAIN. IN ESSENCE...THE BEST SYNOPTIC/MESOSCALE UVVS ARE
PROGGED TO OCCUR AND REMAIN WEST AND NORTH OF THE ILM CWA DURING
THE PRE-DAWN TUE HOURS. AND AS A RESULT...HAVE ALIGNED THE HIER
POPS ACROSS THE NORTHERN AND WESTERN PORTIONS OF THE ILM CWA. FOR
THE EASTERN AND SOUTHERN PORTIONS OF THE ILM CWA...YOU WILL FIND
MUCH LOWER CHANCE POPS. THIS PLAN OF ACTION ALIGNS UP NICELY WITH
OUR NEIGHBORING CWAS. LATEST LIGHTNING OBSERVING NETWORK CONTINUES
TO INDICATE A LACK OF ANY STRIKES ACROSS THE FA UP TO THIS
POINT IN TIME. ONLY A FEW SELECT UPSTREAM TSTORMS HAVE EXHIBITING
LIGHTNING. WILL THEREFORE CONTINUE TO INDICATE NO THUNDER FOR THE
REMAINDER OF THIS EVENING. HOWEVER...DID ILLUSTRATE ISOLATED
THUNDER DURING THE PRE-DAWN TUE HRS...AND CONTINUED THAT INTO
THE DAYLIGHT TUE MORNING HRS. PROGGED OVERNIGHT TSTORM PARAMETERS
RATHER WEAK BUT NEVERTHELESS PRESENT ENUF TO INCLUDE ISOLATED
THUNDER. CAE`S LONE SVR ISSUED THIS EVENING CONFIRMS THE POSSIBILITY
OF THUNDER BUT LATER TONIGHT ACROSS THE ILM CWA.

LATEST OBSERVED TEMPS/DEWPOINTS HAVE BEEN TWEAKED TO ACCOUNT FOR
LATEST READINGS AND TRENDS. WHAT MAKES IT DIFFICULT FOR THE
OVERNIGHT MIN TEMP FORECAST IS THAT ANY PCPN THAT OCCURS ACROSS
THE FA...MAY LOWER TEMPS TO AT OR BELOW THE CURRENT MIN TEMP
FORECAST FOR THAT AREA. OVERALL...TEMPS ACROSS THE FA MAY LOWER A
FEW MORE DEGREES AND THEN BASICALLY REMAIN STEADY FOR THE
REMAINDER OF THE OVERNIGHT PERIOD.

PREVIOUS DISCUSSION...............................................
AS OF 300 PM MONDAY...SCATTERED SHOWERS HAVE DEVELOPED ACROSS THE
AREA AS EXPECTED...THANKS TO MOIST ADVECTION ON S/SE WINDS AROUND A
SURFACE HIGH PRESSURE CENTERED WELL OFFSHORE. SHOWERS HAVE DEVELOPED
ALONG CONVERGENT BOUNDARIES...SINCE MORE WIDESPREAD ACTIVITY IS
LIMITED BY A DECENT INVERSION ABOVE 800MB...AND PERSISTENT VERY DRY
AIR IN THE MID-LEVELS. THIS INVERSION IS PROGGED TO SLOWLY ERODE
THROUGH THE REMAINDER OF THE AFTN INTO THIS EVENING...AS MID-LEVEL
THICKNESSES DECREASE IN ADVANCE OF AN APPROACHING UPPER LOW AND COLD
FRONT. AT THE SAME TIME...MID-LEVELS WILL MOISTEN TONIGHT...AND THUS
PRECIPITATION WILL HAVE THE POTENTIAL TO BECOME MORE WIDESPREAD
THROUGH TONIGHT.

HOWEVER...THE NATURE OF THE SHOWERS HAS BEEN PRIMARILY
CONVECTIVE...ALBEIT OF SHALLOW NATURE. THUS WITH LOSS OF DIURNAL
HEATING...THERE IS LIKELY TO BE A PERIOD OF REDUCED
COVERAGE/ACTIVITY AFTER DARK BEFORE PRECIP RAMPS BACK UP AGAIN
TOWARDS DAYBREAK. HAVE SHOWN THIS IN POP GRIDS...THE EXCEPTION BEING
OVER THE WATERS WHERE ACTIVITY MAY BLOSSOM OVER THE GULF STREAM AND
ADVECT INTO THE COASTAL WATERS (POSSIBLY ONSHORE AS WELL)...BUT THE
MOST SIGNIFICANT RAINFALL WILL HOLD OFF UNTIL AFTER THIS PERIOD.

TEMPS TONIGHT WILL REMAIN QUITE WARM AS SOUTHERLY WINDS INCREASE
OVERNIGHT AS THE PRESSURE GRADIENT TIGHTENS. HAVE SHOWN A
NON-TYPICAL DIURNAL CURVE...WITH MINS BEING REACHED A FEW HOURS
AFTER MIDNIGHT...AND THEN RISING TOWARDS DAWN. LOWS WILL BE IN THE
MID/UPR 60S...SUPPORTING VERY LITTLE DIURNAL CHANGE OVERNIGHT.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM TUESDAY THROUGH 6 AM TUESDAY/...
AS OF 300 PM MONDAY...A STRONG COLD FRONT WILL MOVE MOVE THROUGH THE
AREA TUESDAY BRINGING SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS.  WINDS AT H8 ARE FORECAST TO BE IN THE 50 TO 55 KT
RANGE WITH 0-3 KM SRH VALUES IN EXCESS OF 300 DURING THE AFTERNOON
WHEN A SQUALL LINE IS EXPECTED TO MOVE THROUGH.  MAX TEMPERATURES IN
THE MID TO UPPER 70S WILL YIELD CAPE VALUES BELOW 1000 J/KG BUT
THERE STILL IS SOME POTENTIAL FOR TEMPERATURES IN THE LOWER 80S
WHICH WOULD YIELD CAPES AROUND 2000 J/KG AND ENHANCE SEVERE WEATHER
POTENTIAL.

SHOWERS AND STORMS END RAPIDLY BY ABOUT 03Z WEDNESDAY WITH FROPA
FOLLOWED BY STRONG CAA RESULTING IN TEMPERATURES FALLING TO THE MID
30S TO AROUND 40.  GUIDANCE HAS TRENDED COLDER TUESDAY NIGHT AND
THERE IS SOME POTENTIAL FOR NEAR FREEZING TEMPERATURES NW BUT WILL
WAIT TO SEE LATER MODEL RUNS TO SEE IF THE TREND CONTINUES.

MAINLY CLEAR SKIES ARE EXPECTED WEDNESDAY WITH CAA CONTINUING ON N
TO NE FLOW WHICH SHOULD YIELD MAX TEMPERATURES IN THE UPPER 50S TO
LOWER 60S.  AT THIS TIME...CONTINUED LIGHT WINDS AND A SLIGHT
INCREASE IN CLOUDS...ESPECIALLY NE...SHOULD PRECLUDE A FREEZE BUT
SOME FROST IS NOT OUT OF THE REALM OF POSSIBILITY...ESPECIALLY
WESTERN AREAS.  MINS WILL BE IN THE MID TO UPPER 30S.

&&

.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...STRONG HIGH PRESSURE CENTERED ACROSS NEW
ENGLAND AND THE CANADIAN MARITIMES WILL REMAIN IN PLACE...AND MAY
PERSIST INTO FRI...ALTHOUGH THE PRESSURES WILL BE LOWERING WITH
TIME...AN INDICATION THAT THE WEDGE WILL BE WEAKENING WITH TIME.
LATEST MODEL DATA INDICATES THE ORIENTATION OF THE WEDGE AND ITS
EASTWARD EXTENSION DOES NOT SUPPORT THE DEVELOPMENT OF A COASTAL
TROUGH NEAR THE COAST. THE DEVELOPING AND PRONOUNCED TROUGH
INITIALLY OFFSHORE DOES MIGRATE CLOSER TO THE COAST BY THE WEEKEND
AS THE UPSTREAM TROUGH STRUGGLES TO GAIN PROXIMITY AS THE UPPER
SUPPORT REMAINS WELL AWAY FROM THE SOUTHEAST AND IS LIFTING NE AND
FURTHER AWAY. THE CLOSER THE TROUGH IS TO THE COAST...THE GREATER
THE ISENTROPIC LIFT POTENTIAL AND THE HIGHER THE RISK FOR RAINFALL.

THE GFS AND EUROPEAN MODELS ARE SHOWING VERY DIVERSE SOLUTIONS THIS
WEEKEND AND EARLY NEXT WEEK. THE EURO IS POINTING TO A WET FRI NIGHT
AND SAT AS LOW PRESSURE MOVES OUT OF THE GULF OF MEXICO AND UP THE
SOUTHEAST COAST. THE GFS KEEPS PRECIPITATION OFFSHORE DURING THIS
TIME...BUT DOES BRING A WAVE OF LOW PRESSURE AND A SLUG OF DEEPER
MOISTURE ACROSS THE FORECAST AREA LATE IN THE WEEKEND AND ON MON
WITH A FRONTAL BOUNDARY STALLED NEAR IF NOT OVER THE FORECAST AREA.
THE EURO ON THE OTHER HAND DOES NOT BRING THIS WAVE ACROSS THE AREA
UNTIL MON NIGHT. THUS...THE WEEKEND AND EARLY NEXT WEEK FORECAST IS
VERY MUCH A LOW CONFIDENCE FORECAST AND WILL BENEFIT FROM MODEL
CONSISTENCY IF NOT A MORE UNIFIED SOLUTION WITH LATER RENDITIONS.

TEMPERATURES WILL STILL BE COOL AND WELL BELOW NORMAL ON THU...WITH
A SLOW MODERATING TREND THROUGH MON. HIGHS THU ARE NOT EXPECTED TO
EXCEED THE LOWER TO PERHAPS MID 60S. WE WILL ADD ABOUT 5 DEGREES TO
THAT ON FRI WITH TEMPS BACK TO NORMAL FOR THE WEEKEND AND MON...
LOWER TO MID 70S. LOWS WILL BE CHILLY LATE WEEK...AROUND 40 THU
NIGHT...NO FREEZE IS EXPECTED. MINIMUMS WILL BE ON THE UPSWING INTO
EARLY NEXT WEEK...RETURNING TO NEAR NORMAL FRI NIGHT AND THEN ABOVE
NORMAL SAT NIGHT AND SUN NIGHT.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
AS OF 00Z...A MIX OF MVFR/IFR WITH POSSIBLE BRIEF PERIODS VFR
EXPECTED THROUGH THE OVERNIGHT HOURS AS LOWERED CIGS AND ISOLATED
SHOWERS MOVE THROUGH. LOWERED RESTRICTIONS CONTINUE INTO TUESDAY
WITH INCREASING CHANCES FOR WIDESPREAD RAINFALL AND ISOLATED TO
SCATTERED THUNDERSTORMS...SOME SEVERE.

VFR/MVFR/IFR CONDITIONS ARE CURRENTLY AFFECTING THE AREA TAF SITES
THIS EVENING AS VARYING CEILING HEIGHTS AND ISOLATED SHOWERS MOVE
ACROSS THE AREA...WHICH IS EXPECTED TO PREVAIL THROUGH THE
OVERNIGHT HOURS. SOUTH-SOUTHWEST WINDS WILL CONTINUE AOB 10 KTS
WITH OCCASIONAL GUSTS AROUND 15-20 KTS POSSIBLE. ON TUESDAY
CONFIDENCE REMAINS LOWERED REGARDING FLIGHT RESTRICTIONS GIVEN
VARYING CLOUD HEIGHTS AND SHOWERS...OVERALL THOUGH ANTICIPATE
MVFR/IFR AGAIN WITH INTERMITTENT IMPROVEMENTS TO VFR POSSIBLE.
CHANCES INCREASE THROUGHOUT THE DAY FOR THUNDERSTORMS...WITH THE
POSSIBILITY OF SOME BEING SEVERE...THOUGH CONFIDENCE IS LOW IF THE
ANTICIPATED LINE OF CONVECTION WILL MAKE IT TO THE COAST. PRIMARY
THREAT WITH POSSIBLE SEVERE WEATHER WILL BE DAMAGING WINDS. SOUTH-
SOUTHWEST WINDS WILL CONTINUE ON TUESDAY AOB 10-15 KTS WITH HIGHER
GUSTS POSSIBLE...ESPECIALLY IN STRONGER STORMS.

EXTENDED OUTLOOK...BECOMING LATE VFR TUESDAY NIGHT...CONTINUING
THROUGH THURSDAY. POSSIBLE FOG/STRATUS FRIDAY AND SATURDAY...LOW
CONFIDENCE.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 PM MONDAY...WIND SPEEDS STILL SLOW TO INCREASE ACROSS
THE COASTAL WATERS DUE TO THE STABLE LOW LEVEL MARINE LAYER
INDUCED BY THE COOL SHELF WATERS WITH READINGS IN THE LOW TO MID
60S. LATEST 41013 BUOY JUST OUTSIDE THE COASTAL WATERS...HAS
FINALLY SHOWN AN INCREASE IN THE SOUTHERLY WINDS. AS THE SFC PG
TIGHTENS OVERNIGHT...WIND SPEEDS WILL FOLLOW SUIT. COULD SEE WIND
GUSTS UP TO 25 KT LATE TONIGHT AS THE LOW LEVEL STABLE MARINE
LAYER DECREASES IN DEPTH...ALLOWING SOME OF THOSE HIER WINDS JUST
OFF THE DECK TO DROP DOWN TO THE OCEAN SFC. THE SFC PRESSURE
PATTERN WILL CONTINUE TO PRODUCE A SOUTHERLY WIND DIRECTION
THROUGH DAYBREAK TUE.

BUILDING SIGNIFICANT SEAS WILL HIGHLIGHT THE OVERNIGHT PERIOD
...AND CONTINUE INTO DAYLIGHT TUE. CURRENTLY...THE MAJORITY OF
THE SIGNIFICANT SEAS MAKE-UP COMES FROM A SE-S...7 TO 8 SECOND
PERIOD...PSEUDO SWELL FROM THE OFFSHORE WATERS. THIS A RESULT OF
THE STRONGER WINDS FURTHER OFFSHORE HAVING A DECENT FETCH TO
BUILD UPON. WIND DRIVEN WAVES WILL BECOME THE DOMINANT
CONTRIBUTOR TO SIGNIFICANT SEAS BY DAYBREAK TUE...WITH AVERAGE
PERIODS AT 5 TO 6 SECONDS.

PREVIOUS DISCUSSION...............................................
AS OF 300 PM MONDAY...HIGH PRESSURE WELL OFFSHORE WILL SLOWLY
RETREAT TO THE EAST THROUGH TONIGHT...AS A COLD FRONT APPROACHES
FROM THE WEST. THIS WILL DRIVE THE CURRENT 10 KT S/SE WINDS UPWARD
THROUGH THE PERIOD...BECOMING 15-20 KTS TONIGHT WITH A SLIGHT
VEERING TO THE SOUTH. THESE STRONGER WINDS AND CONTINUED LONG
DURATION FETCH AROUND THE HIGH PRESSURE WILL FORCE WAVE HEIGHTS TO
AMPLIFY TONIGHT. EXPECT WAVE HEIGHTS TO GROW TO 4-6 FT
OVERNIGHT...AND THE SMALL CRAFT ADVISORY HAS BEEN EXTENDED TO BEGIN
AT 8PM TONIGHT FOR ALL THE COASTAL WATERS.

SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED
THROUGH MUCH OF THE PERIOD WITH S TO SW WINDS OF 20 TO 25 KT TUESDAY
WHICH WILL SHIFT TO N TO NE AFTER THE FROPA TUESDAY NIGHT AND
INCREASE TO 25 TO 30 KT.  N TO NE WINDS WILL CONTINUE THROUGH WED
NIGHT AS THEY GRADUALLY DIMINISH TO 15 TO 20 KT.  SEAS WILL BUILD TO
6 TO 8 FT ON THE OPEN WATERS TUESDAY...MAY RELAX A LITTLE AS THE
FRONT GOES THROUGH...THEN BUILD AS HIGH AS 9 FT TUESDAY NIGHT.  SEAS
WILL SLOWLY SUBSIDE WEDNESDAY AND WEDNESDAY NIGHT BUT RESIDUAL 6
FOOTERS ARE POSSIBLE AT 20 NM AROUND DAYBREAK THURSDAY.  FOR NOW SCA
HAS BEEN EXTENDED THROUGH 2 AM THURSDAY BUT MAY NEED TO BE EXTENDED
FURTHER IN TIME IN LATER FORECASTS.

LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...A PROLONGED PERIOD OF SMALL CRAFT ADVISORY
CONDITIONS...ASSOCIATED WITH A COOL WEDGE OF HIGH PRESSURE AND ITS
ASSOCIATED TIGHT PRESSURE GRADIENT...IS EXPECTED TO DROP BELOW
THRESHOLDS THU NIGHT OR FRI. SEAS OF 6 FT ACROSS PORTIONS OF THE
OUTER WATERS WILL BE THE LAST TO DROP BELOW THRESHOLD. THE
JUXTAPOSITION OF A DEVELOPING COASTAL TROUGH MAY COMPLICATE THE WIND
FORECAST FRI THROUGH SAT. AT THIS TIME...WILL KEEP NE WINDS
THROUGHOUT THE PERIOD...HIGHEST THU AND THU NIGHT...UP TO 20 TO 25
KT. SEAS WILL BE HIGHEST DURING THIS TIME AS WELL...UP TO 5 TO 7 FT.
-- End Changed Discussion --

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR AMZ250-252-
     254-256.

&&

$$
SYNOPSIS...RAN
NEAR TERM...DCH/JDW
SHORT TERM...RAN
LONG TERM...RJD
AVIATION...SGL