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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KMHX 182311
AFDMHX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
711 PM EDT TUE JUN 18 2013

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE THROUGH EASTERN NORTH
CAROLINA LATE TONIGHT AND EARLY WEDNESDAY. WEAK HIGH
PRESSURE WILL BUILD IN FROM THE NORTH WEDNESDAY INTO THE
WEEKEND. THE HIGH WILL MOVE OFFSHORE AND CONTINUE TO EXTEND INTO
THE REGION THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /TONIGHT/...
-- Changed Discussion --
AS OF 7 PM TUESDAY...NO SIG CHANGES NEEDED TO ONGOING FORECAST AT
THIS TIME...JUST TWEAKED GRIDS SLIGHTLY BASED ON LATEST TRENDS.
LATEST SFC ANALYSIS SHOWS COLD FRONT DRAPED THROUGH CENTRAL NC.
LATEST RADAR IMAGERY SHOWS LINE OF SHOWERS AND TSTMS MOVING
THROUGH CENTRAL NC EARLY THIS EVENING...AND SHOULD MAKE IT INTO
THE NORTHERN COASTAL PLAIN BY 8PM. THE 12Z UPPER AIR ANALYSIS
INDICATED A VERY MOIST AIRMASS IN PLACE ACROSS EASTERN NC WITH PW
VALUES OF 2" (150% OF NORMAL)...850 MB DEWPOINTS AROUND 15C AND
SURFACE DEWPOINTS IN THE 70S. SURFACE OBSERVATIONS AND SATELLITE
IMAGERY INDICATE NUMEROUS BREAKS IN THE CLOUDS THIS AFTERNOON
WHICH HAS ALLOWED SUFFICIENT SURFACE HEATING TO PRODUCING MODERATE
INSTABILITY WITH LI VALUES -4/-5 AND SURFACE/MU CAPES OF 2000 TO
2500 J/KG. OBSERVED SHEAR WAS MARGINAL ROUGHLY AROUND 25 KT BUT IS
FORECAST TO INCREASE SLIGHTLY TO AROUND 35 KT THIS AFTERNOON WITH
THE APPROACH AND PASSAGE OF A LOW AMPLITUDE MID LEVEL SHORTWAVE
THIS EVENING. IF THE INCREASED SHEAR MATERIALIZES THEN THIS WILL
INCREASE THE CHANCES OF THUNDERSTORM ORGANIZATION WITH MULTI CELL
CLUSTERS CAPABLE OF PRODUCING A LOW END SEVERE WIND THREAT. VERY
ISOLATED TORNADO THREAT EXISTS THIS EVENING FOR THE NORTHERN
CWA...AS CELLS W OF THE CWA MOVE EASTWARD...WHICH HAVE A HISTORY.
THE MAIN THREAT STILL LOOKS LIKE LOCALLY HEAVY RAINS AND MINOR
FLOODING IN POOR DRAINAGE AREAS. PW VALUES WILL BE AOA 2" AND THE
REGION WILL BE IN THE RIGHT ENTRANCE REGION OF THE UPPER JET
PRODUCING DEEP ASCENT. ONLY CHANGE TO POPS WAS TO DELAY HIGHEST
POPS BASED ON RADAR...AND INCREASE SLIGHTLY FOR THE NORTHERN CWA.
WILL CONTINUE WITH LIKELY POPS THROUGH THE EVENING THEN BEGIN TO
TAPER THEM OFF LATE WESTERN PORTION. OVERNIGHT LOWS ARE EXPECTED
TO BE WITH A FEW DEGREES OF 70 INLAND AND THE LOWER TO MIDDLE 70S
BEACHES.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY/...
AS OF 340 PM TUESDAY...THERE CONTINUE TO BE DIFFERENCES IN THE
MODELS REGARDING THE THE TIMING OF THE FRONTAL PASSAGE EARLY
WEDNESDAY AND THE AMOUNT OF POST FRONTAL DRYING WITH THE GFS BEING
THE WETTEST. WILL USE A BLEND OF THE GUIDANCE INDICATING THE
HIGHEST POPS EARLY AND MAINLY ACROSS THE SOUTHERN PORTION OF
EASTERN NC. NORTHERN AREAS SHOULD BE MOSTLY DRY AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE NORTH. FORECAST HIGHS WILL RANGE
FROM THE LOWER 80S INLAND TO THE MIDDLE 70S BEACHES.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
AS OF 405 PM TUES...BROAD UPPER TROUGH WILL PUSH OFF THE
NORTHEASTERN STATES WED NIGHT INTO THURS WITH UPPER RIDGING
BUILDING IN FROM THE WEST. WEDNESDAYS COLD FRONT WILL STALL SOUTH
OF THE REGION THURS AND FRI WITH DRIER CONDITIONS EXPECTED AS THE
SURFACE RIDGE OVER THE MID-ATLANTIC NOSES SW OVER EASTERN NC.
LATEST GUIDANCE HEDGES CLOSER TO A DRIER SOLUTION FOR THE WEEKEND
WITH THE FRONT WELL SE OF THE AREA AND PWATS FALLING TO AND INCH
OR SO...LEADING TO VERY PLEASANT CONDITIONS FRI AND SAT. 00Z/12Z
GFS KEEPS THE RIDGE OVER THE AREA THROUGH SUN WHILE THE 12Z ECMWF
NOW BRINGS A WEAK INVERTED TROUGH ALONG THE COAST. WILL HEDGE
CLOSER TO THE MORE CONSISTENT GFS OVER THE PAST FEW DAYS. SURFACE
RIDGE SHIFTS FARTHER OFFSHORE MON INTO TUES WITH RETURN SOUTHERLY
FLOW SETTING UP ALLOWING DEWPOINTS/PWATS TO INCREASE. TRIED TO
PICK A MIDDLE ROAD AND HIGHLIGHT ONLY THE SOUTHERN COASTAL
COUNTIES FOR PRECIP CHANCES MON AND TUES AFTERNOON WHERE DIURNAL
/SEA-BREEZE CONVECTION IS POSSIBLE.

NE-E FLOW ACROSS THE REGION THURS AND FRI WILL KEEP TEMPS A FEW
DEGREES BELOW CLIMO...IN THE LOW TO MID 80S. WINDS SHIFTING SE
THROUGH THE WEEKEND AND TEMPS GRADUAL WARM BACK INTO THE MID/UPPER
80S. TEMPS MON AND TUES BUILD BACK NEAR 90 AS LOW LEVEL
THICKNESSES BUILD 1400-1410 METERS. SHOULD THE INVERTED TROUGH
INDICATED BY THE 12Z ECMWF COME TO FRUITION...TEMPS COULD BE A FEW
DEGREES BELOW CLIMO SUN-TUES.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
SHORT TERM /THROUGH WEDNESDAY/...
AS OF 7 PM TUESDAY...SCATTERED TO NUMEROUS SHOWERS AND STRONG
THUNDERSTORMS CONTINUE TO DEVELOP ALONG AND JUST AHEAD OF A COLD
FRONT IN CENTRAL NC. OUTSIDE OF THE SHOWERS AND STORMS WE ARE
EXPECTING PRIMARILY VFR CONDITIONS THROUGH ABOUT 06Z. THEN BEHIND
THE FRONT WHILE THE SHOWER THREAT WILL CONTINUE FOR SEVERAL
HOURS...WIDESPREAD MVFR CEILINGS ARE EXPECTED WHICH COULD POSSIBLY
DROP TO IFR AROUND DAWN...ESP FOR OAJ/EWN. IN THE SHOWERS AND
STORMS MVFR TO IFR CONDITIONS ARE EXPECTED THROUGH AT LEAST EARLY
WEDNESDAY.

THERE REMAINS CONSIDERABLE DIFFERENCES IN THE DETERMINISTIC MODELS
WITH RESPECT TO THE AMOUNT OF DRYING THAT WILL OCCUR BEHIND THE
FRONT WEDNESDAY. THE GFS INDICATES CONSIDERABLY MORE SHOWER
ACTIVITY ACROSS EASTERN NC THEN THE NAM. WILL HOLD ON TO THE MVFR
CONDITIONS FOR THE MORNING THEN INDICATE PRIMARILY VFR IN THE
AFTERNOON PER CONSENSUS OF ALL AVAILABLE GUIDANCE.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 400 PM TUES...A COLD FRONT STALL WILL SOUTH OF THE REGION
HIGH PRESSURE BUILDS SOUTH OVER THE TERMINALS BY LATE WEEK WITH
VFR CONDITIONS DOMINATING THROUGH THE WEEKEND.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
SHORT TERM /THROUGH WEDNESDAY/...
AS OF 7 PM TUESDAY...NO SIGNIFICANT CHANGES NEEDED TO PREVIOUS
FORECAST FOR EARLY PM UPDATE. LATEST OBS SHOW SW WINDS 10-20KT
WITH GUSTS TO 25KT AND SEAS 2-4FT NORTH OF OREGON INLET AND 3-6FT
SOUTH. A COLD FRONT WILL BEGIN TO MOVE ACROSS EASTERN NORTH
CAROLINA TONIGHT AND IS FORECAST TO MOVE THROUGH THE WATERS
WEDNESDAY MORNING. AHEAD OF THE FRONT MODERATE SW FLOW TO 20 KT
WITH FREQUENT GUSTS TO 25 KT WILL OCCUR. WEDNESDAY BEHIND THE
FRONT THE FLOW WILL SHIFT TO THE NORTH AT 15 TO 20 KT NORTH OF
OCRACOKE INLET AND 10 TO 15 KT SOUTH OF OCRACOKE. SEAS ARE
FORECAST TO BUILD TO 5 TO 8 FT TONIGHT (HIGHEST CENTRAL WATERS)
AND 4 TO 7 FT ON WEDNESDAY. BASED ON POTENTIAL FOR FREQUENT GUSTS
TO 25 KT HAVE ADDED THE PAMLICO SOUND TO THE SMALL CRAFT
ADVISORIES.

LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 420 PM TUES...A COLD FRONT WILL STALL SOUTH OF THE WATERS
WED NIGHT INTO THURS WITH WINDS SHIFTING NE THROUGH THE END OF
THE WEEK. NE FLOW 10-15 KT WILL PERSIST THURS AND FRI WITH SEAS
3-5 FT NORTH OF DIAMOND SHOALS TO 2-4 FT SOUTH. HIGH PRESSURE WILL
NOSE SOUTH OVER THE WATERS THURS THROUGH SAT. THE HIGH WILL SHIFT
FARTHER OFFSHORE SUN AND EXPECT WINDS TO SHIFT E AND POSSIBLY SE
LATE SUN. LATEST ECMWF SUGGESTS AN INVERTED TROUGH WILL DEVELOP
OFF THE CAROLINA COAST FRI AND SAT...BUT UNCERTAINTY REMAINS AS
TO HOW CLOSE TO THE COAST THIS FEATURE WILL RESIDE AND THUS THERE
IS GREATER UNCERTAINTY IN THE WIND/SEAS FORECAST FOR LATE WEEK
INTO SAT. CURRENTLY EXPECT WINDS SHIFTING E SAT WITH SEAS 2-4 FT.
WINDS WILL SHIFT SE THROUGH THE DAY SUN WITH SEAS 2-3 FT. GOOD
AGREEMENT BETWEEN LOCAL SWAN/NWPS...12Z WAVE WATCH III
GUIDANCE...AND PREVIOUS SEAS FORECAST THUS ONLY MINOR ADJUSTMENTS
NEEDED WITH THE AFTERNOON PACKAGE.
-- End Changed Discussion --

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT WEDNESDAY FOR AMZ152-154.
     SMALL CRAFT ADVISORY FROM 2 AM TO 4 PM EDT WEDNESDAY FOR
     AMZ156-158.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT WEDNESDAY FOR AMZ135.
-- End Changed Discussion --

&&

$$
SYNOPSIS...JME
NEAR TERM...JME/CQD
SHORT TERM...JME
LONG TERM...DAG
AVIATION...JME/CQD/DAG
MARINE...JME/CQD/DAG