Area Forecast Discussion
Issued by NWS Wilmington, NC

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000
FXUS62 KILM 261128
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
727 AM EDT TUE MAY 26 2015

.SYNOPSIS...
BERMUDA HIGH PRESSURE CENTERED OFFSHORE WILL PREVAIL THROUGH THE
WEEK...BRINGING TYPICAL LATE MAY HUMIDITY AND WARMTH. SHOWER AND
THUNDERSTORM CHANCES WILL INCREASE LATER THIS WEEK. HIGH PRESSURE
WILL STRENGTHEN INTO NEXT WEEKEND MAINTAINING WARM CONDITIONS WITH
ONLY SMALL CHANCES OF RAIN.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM TUESDAY...FOR THIS PERIOD...RIDGING ALOFT AND AT THE
SFC TO CONTINUE ITS REIGN ACROSS THE FA.

TO START THE DAY...A WEAK 5H VORT WILL RIDE UP THE SPINE OF THE
APPALACHIANS THIS MORNING...BASICALLY ON THE WEST SIDE OF THE
UPPER RIDGE. ONLY LOOKING AT DEBRIS CLOUDINESS AFFECTING THE
FA...IN THE MID AND UPPER LEVELS...AND MAINLY OCCURRING THIS
MORNING. CLOUDINESS WILL BE THIN AT THE COAST...AND MORE OPAQUE
AS YOU GO WESTWARD AND INLAND ACROSS THE ILM CWA. SPEAKING OF THE
COAST...SMALL BLOB OF CLOUDINESS OVER THE ATLANTIC WATERS IS
PROGGED TO MOVE ONSHORE BETWEEN CAPE FEAR AND ROMAIN THIS MORNING.
MUCH OF IT WILL SCOUR OUT AFTER MOVING INLAND AS IT ENCOUNTERS
MUCH DRIER AIR.

FOR THIS AFTN AND EARLY EVENING...DIURNALLY DRIVEN CU/MDT CU
WILL DEVELOP AND AFFECT THE FA. THE JUICE...CAPE...NEEDED TO
DEVELOP/SUSTAIN CONVECTION ACROSS THE FA IS STILL PROGGED TO BE
JUST NOT ENOUGH DUE TO THE EFFECTS OF THE AIRMASS ACROSS THE FA
ASSOCIATED WITH THE UPPER HIGH.

FOR THE OVERNIGHT PERIOD...THE NE-SW UPPER RIDGE AXIS TO DRIFT
SLIGHTLY FURTHER EAST OF THE FA. THIS MAY ALLOW A SLIGHT EASTWARD
PROGRESSION OF THOSE 5H VORTS TRACKING UP THE SPINE OF THE
APPALACHIANS. AS A RESULT...COULD SEE CLOUDINESS AND CONVECTION
IGNITED BY THESE VORTS SPILL ACROSS THE FAR WESTERN PORTIONS OF THE
FA TOWARD DAYBREAK. ONCE AGAIN...FOG DEVELOPMENT WILL BE LIMITED AND
WILL ONLY CARRY PATCHY FOG ACROSS INLAND LOCATIONS.

AS FOR TEMPS...CONTINUED WITH PERSISTENCE AS A STARTING POINT FOR
BOTH HIGHS/LOWS. ADDED A DEGREE OR 2 FOR MAX TEMPS ACROSS THE
FA...AND A DEGREE TO 3 FOR TONIGHTS MINS.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...SEASONABLE TEMPERATURES BUT WITH INCREASING
HUMIDITY AND CONVECTION CHANCES WILL BE THE RULE FOR THE SHORT TERM.
MID-LEVEL RIDGE WILL SLOWLY DEPART TO THE EAST WEDNESDAY...WITH THE
SURFACE BERMUDA-TYPE HIGH FOLLOWING. THIS SURFACE HIGH WILL CONTINUE
TO RIDGE BACK TOWARDS THE COAST EVEN AS THE CENTER DRIFTS AWAY
HOWEVER...SO WARM AND MOIST RETURN FLOW WILL PERSIST. TEMPS BOTH
DAYS ARE EXPECTED TO CLIMB INTO THE 85-88 DEGREE RANGE ACROSS THE
INLAND ZONES...WITH 80-83 MORE COMMON AT THE BEACHES. WHILE THESE
HIGHS REPRESENT NEAR-NORMAL VALUES...NIGHTTIME LOWS WILL FEATURE
POSITIVE DEPARTURES FROM NORMAL WITH RETURN FLOW LIMITING NOCTURNAL
COOLING TO JUST THE MID 60S...NEAR 70 AT THE COAST.

AT THE SAME TIME...CONVECTION CHANCES WILL RAMP UP THROUGH THE
PERIOD...FOCUSED ON THE DIURNAL MAXIMUMS. INCREASING PWAT AIR WILL
FLOOD INTO THE AREA...ESPECIALLY ALONG THE I-95 CORRIDOR...WHICH
COMBINED WITH THE WARMING TEMPERATURES...BREAKDOWN OF THE MID-LEVEL
RIDGE...AND SOME STRUNG OUT VORT ENERGY WILL ALLOW FOR AT LEAST A
CHC OF SHOWERS AND TSTMS. NOTE THAT SPC DOESN`T EVEN HAVE A GENERAL
RISK FOR WEDNESDAY...AND THURSDAY IS DEFINITELY THE FAVORED
DAY...BUT WILL CONTINUE WITH THE INHERITED CHC POP BOTH
AFTNS...WANING TO SILENT/SCHC AT NIGHT. NO STRONG OR ORGANIZED
CONVECTION IS ANTICIPATED.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 AM TUESDAY...HEAT AND HUMIDITY WILL BECOME THE NORM
THROUGH THE LONG TERM AS UPPER RIDGE RE-AMPLIFIES AND SURFACE HIGH
PRESSURE CONTINUES TO RIDGE BACK FROM THE ATLANTIC. UPPER RIDGE
SLOWLY STRENGTHENS OVERHEAD...ESPECIALLY SUNDAY AND MONDAY...WHILE
SURFACE HIGH MAINTAINS ITS INFLUENCE ACROSS THE WESTERN ATLANTIC.
MOIST ADVECTION WEAKENS CONSIDERABLY...AND FORECAST PROFILES SUGGEST
CONSIDERABLE DRY AIR THROUGH THE PERIOD. THIS WILL PERMIT GOOD
INSOLATION AND ALL FACTORS SUGGEST THAT 90 DEGREE TEMPERATURES WILL
BECOME THE NORM AWAY FROM THE COAST DURING THE WKND AND INTO EARLY
NEXT WEEK AS THE CALENDAR FLIPS TO JUNE. WHILE ISOLATED CONVECTION
IS POSSIBLE FRIDAY...IT APPEARS MOST OF THE PERIOD WILL BE DRY...AS
EVEN THE SEA BREEZE AND PIEDMONT TROUGH WILL HAVE TROUBLE
PENETRATING THE DRY AIR ALOFT. LATE IN THE PERIOD WILL SHOW AN
INCREASE IN POP BUT KEEP IT ON THE VERY LOW CHC SIDE AS MOIST
ADVECTION ONCE AGAIN INCREASES ACROSS THE LOCAL AREA. FOR THE MOST
PART HOWEVER...THE EXTENDED WILL BE HOT AND DRY WITH THE
HEAT/HUMIDITY COMBINATION MAKING IT START TO FEEL UNCOMFORTABLE LATE
IN THE PERIOD.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 12Z...BERMUDA HIGH WILL KEEP US IN SOUTHEAST FLOW THROUGH THE
PERIOD. RADAR SHOWS  CONVECTION OFFSHORE THAT MAY CREEP INTO THE
MYRTLES THIS MORNING. LIKEWISE SOME SEA BREEZE ACTIVITY IS EXPECTED
TO DEVELOP BY MID TO LATE MORNING WITH THE MOIST SOUTHEAST FLOW.
CEILINGS WILL BE INTERMITTENTLY MVFR IN THE SHOWERS. THIS CONVECTION
WILL MOVE INLAND BY 17Z...BUT MAY NOT MAKE IT TO THE INLAND
TERMINALS. SOME PATCHY FOG IS POSSIBLE AT THE END OF THE FORECAST
PERIOD.

EXTENDED OUTLOOK...PATCHY MORNING FOG AND LOW CEILINGS POSSIBLE
EACH MORNING. INCREASING CHANCES OF MAINLY AFTERNOON CONVECTION
WEDNESDAY THROUGH FRIDAY. OTHERWISE EXPECT VFR.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM TUESDAY...ANY SLIGHT POSITIONAL MOVEMENT OF THE
ORIENTATION OF THE SFC RIDGE AXIS ACROSS THE FA...WILL HAVE AN
IMPACT ON WIND DIRECTIONS. THE RIDGING ACTUALLY EXTENDS FROM THE
HIGHS CENTER ACROSS THE ATLANTIC HIGH SEAS WELL OFF THE MID-
ATLANTIC COAST. MODELS INDICATE WINDS WILL ROUGHLY RANGE FROM THE
SE ACROSS THE SOUTHERN PORTIONS...AND SSE TO S ACROSS THE NORTHERN
PORTIONS. THE SFC PG REMAINS MODEST AT BEST...WITH 10 TO
OCCASIONALLY 15 KT FOR SPEEDS THRUOUT THE PERIOD. THE RESULTANT
WIND NEAR SHORE THIS AFTN/EARLY EVENING COULD PRODUCE GUSTS TO 20
KT. SIGNIFICANT SEAS WILL RUN 2 TO 3 FT...WITH A FEW 4 FOOTERS
POSSIBLE OUTER WATERS OFF CAPE FEAR. DOMINANT PERIODS WILL RANGE
FROM 6 TO 8 SECONDS...AND COULD BE CONSIDERED A PSEUDO GROUND
SWELL. A BIT OF A WIND CHOP TO OCCUR NEAR SHORE THIS AFTN/EVENING
FROM THE ACTIVE RESULTANT WIND BOUNDARY.

SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 300 AM TUESDAY...BERMUDA HIGH PRESSURE WILL BE THE DOMINANT
FEATURE THROUGH THE SHORT TERM...MAINTAINING ITS INFLUENCE ACROSS
THE WATERS. THIS WILL CREATE A WEAK PRESSURE GRADIENT...WITH WINDS
PERSISTENT FROM THE SE AROUND 10 KTS...WITH LITTLE FLUCTUATION.
WITH THIS PERSISTENT WIND AND THE LIGHT SPEEDS...THE WAVE SPECTRUM
WILL BECOME INCREASINGLY DOMINATED BY A SE GROUND SWELL OF 7-8 SEC
CREATING WAVE HEIGHTS OF 2-3 FT.

LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...BERMUDA TYPE HIGH WILL WEAKEN AND RETREAT
THROUGH THE WEEKEND...BUT WILL CONTINUE TO RIDGE ACROSS THE
WATERS. THE ONLY REAL NOTICEABLE IMPACT TO THIS RETREATING HIGH
WILL BE A SLIGHT BACKING OF THE WINDS FROM SE TO E ON
FRIDAY...BEFORE RETURNING TO THE SE AGAIN SATURDAY. SPEEDS WILL BE
10-15 KTS REGARDLESS OF DIRECTION. THESE WINDS WILL HAVE LITTLE
INFLUENCE TO THE OVERALL WAVE SPECTRUM HOWEVER...AND SEAS WILL BE
2-4 FT WITH A SE 8-9 SEC GROUND SWELL FORMING THE PREDOMINANT WAVE
GROUP.

&&

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

&&

$$
SYNOPSIS...JDW
NEAR TERM...DCH
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...43



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