Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 291846
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
246 PM EDT SAT AUG 29 2015

.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO BECOME CENTERED OFFSHORE TODAY.
MEANWHILE, A WEAK DISTURBANCE IS EXPECTED TO MOVE ACROSS THE
NORTHEAST ON SUNDAY. HIGH PRESSURE OVERALL THOUGH WILL TEND TO
DOMINATE OUR WEATHER THROUGH MUCH OF NEXT WEEK, THEN A WEAK COLD
FRONT MAY SLIDE INTO OUR REGION ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HIGH PRESSURE AT THE SURFACE ACROSS THE AREA WILL CONTINUE TO BECOME
MORE CENTERED OFFSHORE, AND THIS WILL MAINTAIN A SOUTHERLY FLOW
REGIME. MEANWHILE, A SHORT WAVE TROUGH FROM THE MIDWEST TO THE UPPER
GREAT LAKES WILL GRADUALLY SHIFT EASTWARD. OUR WEATHER THROUGH
TONIGHT WILL BE MAINLY DOMINATED BY THE DEPARTING SURFACE HIGH,
THEREFORE A DRY NIGHT IS ANTICIPATED.

THE CUMULUS THIS AFTERNOON IS EXPECTED TO FLATTEN AND DISSIPATE THIS
EVENING WITH THE LOSS OF HEATING, THEN MOSTLY SOME HIGH LEVEL
CLOUDINESS AROUND AT TIMES. THE LIGHT ENOUGH FLOW COMBINED WITH
AMPLE BOUNDARY LAYER HEATING THIS AFTERNOON RESULTED IN A SEA
BREEZE. THIS WILL CONTINUE TO MOVE INLAND SOME BEFORE WASHING OUT
EARLY THIS EVENING. THE SOUTHERLY FLOW HAS HELPED TO INCREASE THE
SURFACE DEW POINTS SOME, ALTHOUGH SOME LOWERING IN SPOTS HAS BEEN
NOTED THIS AFTERNOON DUE TO BOUNDARY LAYER HEATING AND SOME MIXING.
THESE SHOULD EDGE UP A BIT THROUGH THE NIGHT AS COOLING OCCURS AND
THE MOISTURE STARTS TO POOL CLOSEST TO THE SURFACE. THIS COULD ALSO
LEAD TO GROUND FOG IN LOCALIZED SPOTS.

AS FOR THE LOW TEMPERATURES, WE USED MAINLY A NAM/GFS MOS BLEND AND
THESE ARE A LITTLE HIGHER OVERALL WITH THE EXPECTATION THAT THE DEW
POINTS WILL BE HIGHER THAN PREVIOUS NIGHTS.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
A SHORT WAVE TROUGH IS FORECAST TO BE ARRIVING ACROSS THE NORTHEAST
LATER SUNDAY, AND AS IT DOES IT SHOULD TEND TO WEAKEN. A WEAK COLD
FRONT AT THE SURFACE IS TIED TO THIS FEATURE, AND WITH SOME MOISTURE
ON THE INCREASE THERE SHOULD BE SOME SHOWERS AND THUNDERSTORMS WITH
IT TO OUR WEST. THE QUESTION IS WHETHER THIS ACTIVITY CAN BE
MAINTAINED AS IT APPROACHES OUR WESTERN ZONES MAINLY LATER IN THE
AFTERNOON. THERE IS SOME INSTABILITY DURING THE DAY AND INTO THE
EVENING, WITH THIS PROBABLY BETTER ACROSS THE WESTERN ZONES.
HOWEVER, THE FORECAST SOUNDINGS MOSTLY SHOW A SKINNY CAPE PROFILE
WHICH TENDS TO KEEP UPDRAFTS ON THE WEAKER SIDE. THE BULK OF THE
LIFT ASSOCIATED WITH THE TROUGH AXIS IS FORECAST TO BE TO OUR WEST
DURING PEAK HEATING, HOWEVER TERRAIN INFLUENCES AND A WEAK SURFACE
TROUGH COULD COME INTO PLAY AND THEREFORE WE INCLUDED A SLIGHT CHC
POP DURING THE AFTERNOON ACROSS THE NORTHWESTERN ZONES.

IT WILL BE RATHER WARM TO HOT ACROSS MUCH OF THE CWA, HOWEVER DEW
POINTS MAY BE HIGHER IN THE MORNING DUE TO HEATING OF THE BOUNDARY
LAYER ALLOWING FOR SOME DECREASE IN THE AFTERNOON. THE PRESSURE
GRADIENT IS NOT FORECAST TO BE ALL THAT TIGHT, THEREFORE LIGHT
ENOUGH FLOW SHOULD RESULT IN A SEA BREEZE ONCE AGAIN IN THE
AFTERNOON.

AS FOR THE HIGH TEMPERATURES, WE USED AN EVEN MOS BLEND THEN MADE
SOME LOCAL TWEAKS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE LONG TERM ISN`T MUCH MORE EXCITING THAN THE SHORT OR NEAR
TERM, WITH HIGH PRESSURE MOSTLY THE DOMINANT FEATURE THROUGH THE
NEXT WEEK.

SUNDAY NIGHT...A WEAK UPPER LEVEL SHORT WAVE TROUGH WILL CROSS
THE REGION, BUT IT SHOULD BE FILLING AND WEAKENING AS IT DOES SO.
THUS, CHANCES FOR ANY PRECIPITATION IN OUR AREA ARE SLIM, SO HAVE
KEPT THE PERIOD DRY.

MONDAY THROUGH TUESDAY...HIGH BUILDS FURTHER EAST THROUGH THIS
TIME, WITH THE RIDGE AXIS OVER THE REGION BY TUESDAY EVENING. THE
SHORT WAVE TROUGH THAT EARLIER MODEL RUNS HAD SHOWN DIGGING
THROUGH THE REGION ON TUESDAY EVENING HAS ALL BUT DISAPPEARED,
MEANING RAIN CHANCES HAVE ALSO DECREASED. SO HAVE CHANGED THE
FORECAST TO HAVE NO MENTION OF SHOWERS THROUGH THIS TIME. WITH THE
HIGH BUILDING IN, 1000-500 MB THICKNESSES WILL ALSO INCREASE
THROUGH THIS PERIOD, LEADING TO A MODEST WARMING TREND DESPITE THE
LACK OF ANY LOW LEVEL WARM AIR ADVECTION.

WEDNESDAY THROUGH FRIDAY...WEAK COLD FRONT LOOKS TO SLIDE IN FROM
THE NORTH THROUGH THIS TIME. HOWEVER, THE FRONT SHOULD BE SLOWING
AS FRONTOLYSIS BEGINS THROUGH THIS PERIOD, SO DO NOT ANTICIPATE
AND SIGNIFICANT COOLING TREND. HOWEVER, THE FRONT COULD SERVE AS A
FOCUS FOR LOW LEVEL CONFLUENCE LEADING TO SOME RAIN CHANCES
THROUGH THIS PERIOD.

&&

.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

REST OF THIS AFTERNOON...VFR WITH SOME CUMULUS AT AROUND 5000 FEET.
SOUTH-SOUTHWEST WINDS UP TO 10 KNOTS. A SEA BREEZE SHOULD TURN THE
WINDS MORE SOUTH OR SOUTH-SOUTHEAST AT KACY, WITH THIS ALSO
OCCURRING AT KILG DUE TO A BAY BREEZE.

TONIGHT...VFR OVERALL WITH REMAINING CUMULUS DISSIPATING IN THE
EVENING. THERE IS A CHANCE FOR LOCALIZED MVFR FOG TOWARD SUNDAY
MORNING. WINDS BECOMING LIGHT SOUTHWEST OR LIGHT AND VARIABLE AT
MOST TERMINALS, TO LOCALLY CALM.

SUNDAY...PERHAPS LOCALIZED MVFR FOG EARLY, OTHERWISE VFR WITH SOME
CUMULUS AROUND 5000 FEET. SOUTHWESTERLY WINDS INCREASING UP TO 10
KNOTS, WHICH SHOULD TURN MORE SOUTHERLY AT KACY AND PERHAPS KILG DUE
TO A SEA/BAY BREEZE.

OUTLOOK...
SUNDAY NIGHT THROUGH TUESDAY...MOSTLY VFR CONDITIONS EXPECTED,
LOCALIZED MVFR POSSIBLE WITH BR EACH MORNING.

WEDNESDAY...MOSTLY VFR CONDITIONS EXPECTED, ISOLATED THUNDERSTORMS
POSSIBLE LATE IN THE DAY.

&&

.MARINE...
HIGH PRESSURE BECOMING MORE CENTERED OFFSHORE WILL ALLOW FOR A
SOUTHERLY FLOW THROUGH SUNDAY. WHILE THE WIND SPEEDS ARE EXPECTED TO
BE BELOW SMALL CRAFT ADVISORY CRITERIA, SOME INCREASE IS EXPECTED
THROUGH THIS EVENING MOSTLY DUE TO A SEA BREEZE INFLUENCE NEARSHORE.
THIS MAY ALSO OCCUR AGAIN SUNDAY AFTERNOON. SEAS MAINLY 3 FEET OR
LESS.

OUTLOOK...
SUNDAY NIGHT...A FEW GUSTS NEAR OR ABOVE 20 KT POSSIBLE IN THE EVENING,
OTHERWISE WINDS AND SEAS SHOULD STAY BELOW SMALL CRAFT ADVISORY
CRITERIA.

MONDAY THROUGH WEDNESDAY...WINDS AND SEAS SHOULD STAY WELL BELOW
SMALL CRAFT CRITERIA.

&&

.RIP CURRENTS...
A LONG PERIOD /AROUND 11 SECONDS/ EAST-SOUTHEAST SWELL CONTINUES
INTO TONIGHT, WITH SEAS IN THE 2-3 FOOT RANGE. A FULL MOON
/HIGHER TIDE LEVELS/ AND A SOUTHERLY WIND WILL ALLOW FOR TRICKY
CONDITIONS AT TIMES IN THE SURF ZONE ESPECIALLY FOR NEW JERSEY. AS A
RESULT A MODERATE RISK OF DANGEROUS RIP CURRENTS ALONG THE NEW
JERSEY COAST CONTINUES THROUGH THIS EVENING, HOWEVER A LOW RISK IS
MAINTAINED FOR THE DELAWARE BEACHES.

OUTLOOK...
SUNDAY...APPEARS TO BE LOW ENHANCED WITH RESIDUAL IMPACT FROM TODAYS
3 FT 11-12 SECOND SE SWELL BUT THE SWELL SHOULD BE SUBSIDING
SOMEWHAT ON SUNDAY. STILL FULL MOON IMPACT SO LARGER THAN NORMAL
TIDAL EXCHANGE.

MONDAY AND ONWARD FOR NEXT WEEK...CURRENTLY LOOKING TO BE A DAILY
LOW RISK.

CONCERN: ABOVE NORMAL SST`S (UPPER 70S) AND ABOVE NORMAL TEMPS
THIS LAST FULL WEEK OF SUMMER AND FOLKS BEING TOO CASUAL SINCE THE
RC RISK IS LOW. FOR GREATEST SAFETY... SWIM IN THE PRESENCE OF
LIFE GUARDS AND DURING THEIR COVERAGE HOURS. SWIMMING AT JETTIES,
PIERS, GROINS IS ILL ADVISED SINCE RC REPEATEDLY FORM THERE.
SWIMMING AT NIGHT OR NOT IN SIGHT OF LIFE GUARDS IS RISKY. WATER
TROUBLE CAN QUICKLY TURN TO RECOVERY INSTEAD OF RESCUE.

&&

.CLIMATE...
WE HAVE LOOKED AT RECORDS FOR NEXT WEEK (NEAR 100F IN 1953) AND SO
WHILE CONFIDENCE IS VERY HIGH IN A HEAT WAVE OCCURRING NEXT WEEK,
NOT ENOUGH HEAT IS INDICATED TO CHALLENGE THE RECORDS. RECORD
HIGHS NEXT FRIDAY, SATURDAY AND SUNDAY ARE LOWER BUT NOT SURE IF
ONSHORE FLOW PREVAILS, THEREFORE KEEPING IT COOLER THAN RECORD.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...GORSE/JOHNSON
NEAR TERM...GORSE
SHORT TERM...NIERENBERG
LONG TERM...DRAG/JOHNSON
AVIATION...GORSE/JOHNSON
MARINE...JOHNSON/NIERENBERG
RIP CURRENTS...DRAG/GORSE
CLIMATE...DRAG


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