Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 250142
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
942 PM EDT SUN AUG 24 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH TUESDAY.
A COLD FRONT WILL SAG SOUTHEAST INTO THE MID ATLANTIC STATES LATE
WEDNESDAY OR THURSDAY. THEN THE NATIONAL HURRICANE CENTER TRACKS
CRISTOBAL OUT TO SEA WELL TO THE EAST OF THE CAROLINAS LATE THIS
WEEK. A MORE SUMMERLIKE WARM HUMID PATTERN APPEARS TO BE UNFOLDING
FOR NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MINIMAL CHANGES NEEDED TO THE GRIDS THIS EVENING AS THE FORECAST
REMAINS ON TRACK. JUST ABOUT ALL THE STRATOCU HAS ERODED WITH JUST
SOME POCKETS LEFT ACROSS THE EASTERN SHORE.

OTHERWISE, AS THE SURFACE HIGH STARTS TO SETTLE OVERHEAD AND WE
LOSE THE MIXING, THE SURFACE WINDS ARE ANTICIPATED TO BECOME
RATHER LIGHT FOR MUCH OF THE AREA. THE ONE EXCEPTION MAY BE ALONG
THE COAST AND PORTIONS OF THE DELMARVA DUE TO THE ONSHORE FLOW AND
A LONGER FETCH INTO THESE AREAS. THIS COULD RESULT IN A BIT MILDER
TEMPERATURES OVERNIGHT HERE, AND ELSEWHERE IT WILL BE A COOL
NIGHT. SOME PATCHY FOG CANNOT BE RULED OUT LATE, MAINLY ACROSS THE
NORTHWEST ZONES WHERE COOL TEMPERATURES WILL PROMOTE NEAR-GROUND
SATURATION. ELSEWHERE, NO FOG WAS INCLUDED ATTM.

AS FOR LOW TEMPERATURES, WE USED AN EVEN BLEND OF THE NAM/GFS MOS
WITH JUST SOME LOCAL TWEAKS. WE UTILIZED THE LAMP/LAV GUIDANCE IN
THE HOURLY GRIDS INTO THIS EVENING FOR ASSISTANCE.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF A BUILDING RIDGE INTO THE
NORTHEAST AND MID ATLANTIC REGION. WE WILL STILL REMAIN NEAR THE
EASTERN EDGE OF THIS RIDGE AT LEAST THROUGH THE EARLY AFTERNOON
HOURS, AND SURFACE HIGH PRESSURE WILL CONTINUE TO SETTLE OVER OUR
ENTIRE CWA.

AS THIS OCCURS WE WILL STILL HAVE AN ONSHORE FLOW CONTINUING, HOWEVER
IT WILL WILL BE TURNING LIGHTER /EVEN AT THE COAST/ WITH MORE OF A
SEA/BAY BREEZE INFLUENCE TENDING TO TAKE HOLD. THIS WOULD TURN THE
WINDS MORE FROM THE SOUTHEAST DURING THE AFTERNOON HOURS. AS THE
HEIGHTS RISE ACROSS THE REGION, THE AIRMASS WILL CONTINUE TO MODIFY.
THIS WILL RESULT IN A WARMER DAY FOR MUCH OF THE AREA, HOWEVER IT
SHOULD BE COOLER CLOSER TO THE COAST AND ALSO THE DELMARVA GIVEN THE
LINGERING EFFECTS OF THE ONSHORE FLOW. THE DEW POINTS AWAY FROM THE
OCEAN INFLUENCE SHOULD BE MAINLY IN THE 50S WITH THE CONVECTIVE
TEMPERATURES HIGHER. THE FORECAST SOUNDINGS DO SHOULD A SHALLOW
LAYER OF MOISTURE AT THE TOP OF THE MIXING LAYER, THEREFORE A BIT OF
CUMULUS SHOULD DEVELOP. THIS IS ANTICIPATED TO BE LESS THAN WHAT WAS
OBSERVED THIS AFTERNOON /SUNDAY/. OVERALL, AFTER SOME PATCHY FOG
EARLY AN ABUNDANCE OF SUNSHINE IS ANTICIPATED.

AS FOR HIGH TEMPERATURES, WE USED A GENERAL NAM/GFS MOS BLEND.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
500 MB: A STRONG RIDGE OVER THE OHIO VALLEY WILL PROBABLY SHIFT
SLIGHTLY SOUTHEASTWARD INTO THE SOUTHEAST USA NEXT WEEKEND.

TEMPERATURES: ABOVE NORMAL TEMPERATURES TUESDAY AND WEDNESDAY MAY
COOL TO NEAR OR SLIGHTLY BELOW NORMAL THURSDAY AND FRIDAY BEFORE
PROBABLY WARMING UP NEXT WEEKEND.

FORECAST BASIS: UNLESS OTHERWISE NOTED THE LONG TERM PERIOD OF THIS
FORECAST IS GENERALLY BASED ON A 50 50 BLEND OF THE 12Z/24 NAM/GFS
MOS FOR THE PERIOD MONDAY NIGHT - TUESDAY NIGHT...THE 12Z/24 GFS MOS
WEDNESDAY AND WEDNESDAY NIGHT...THEN THEREAFTER (THURSDAY ONWARD) THE
1603Z/24 WPC GRIDDED GUIDANCE WHICH AT TIMES IS BLENDED 50 50 WITH
THE 12Z/24 MEXMOS. ALL THIS IS EVENTUALLY CHECKED AGAINST THE 12Z/24
ECMWF TO SEE IF WE`RE IN THE BALLPARK WITH ECMWF CYCLICALLY
PERSISTENT 18Z 2METER TEMPERATURES. THE PRECIPITATION PROBABILITY
GUIDANCE IS CHECKED AGAINST THE 09Z/24 SREF POPS FOR .01 IN 3 HRS
THROUGH 00Z THURSDAY AND THEREAFTER THE 12Z/24 GEFS 6HR POPS FOR
0.05

THE DAILIES...

MONDAY NIGHT-WEDNESDAY...MOSTLY CLEAR AND INCREASINGLY WARMER WITH A
POSSIBLE SPOTTY HEAT WAVE IN PARTS OF THE DELAWARE VALLEY BEGINNING
TUESDAY. EARLY MORNING FOG MAY OCCUR BOTH EARLY TUESDAY AND
WEDNESDAY FOR THE TYPICAL LOW LYING AREAS BUT NOT A STRONG CHANCE
SINCE ITS SO DRY ALOFT. THE FCST MAX TEMPS ARE IN THE UPPER 80S
AND MAYBE I SHOULD HAVE PUSHED THEM TO 90 OR 91 FOR WEDNESDAY BUT
FOR NOW FCST THE MOST LIKELY MAX TEMPS. NO MATTER...IT WILL BE
VERY WARM...ESPECIALLY FOR THIS AUGUST WHICH HAS BEEN RATHER COOL
(ONLY 1 90 DEGREE DAY THIS MONTH AT PHL AND SIMILAR TEMPS TO LAST
AUGUST 2013 AT PHL)

WEDNESDAY NIGHT...THERE MAY BE A BAND OF SCT THUNDERSTORMS...SWI -2,
TT NEAR 48C WITH 500MB WIND 30-35 KT AND SMALL CHANCE IT MIGHT
RESULT IN AN ISOLATED LATE IN THE SEASON SVR...MAINLY NE PA/NNJ.

THURSDAY...TRANSITION TO SLIGHTLY DRIER AND COOLER. STILL WARM.

FRIDAY-WEEKEND...WPC GRIDDED POPS BASICALLY ACCEPTED. WPC 1603Z
GRIDDED TEMPS WERE RAISED 3-4 DEGREES NEXT WEEKEND TO THE 12Z/24
GFS OPERATIONAL RUN MEX MOS VALUES WHICH IS CONSIDERABLY CLOSER TO
THE 12Z/24 OPERATIONAL ECMWF. THE ECMWF IS  MODELING THICKNESSES
OVER 573DM EACH DAY WITH CREST OF THE RIDGE TSTMS IN OUR AREA OR
NEARBY TO THE NORTH. ACTUALLY LOOKS LIKE A CHALLENGING SUMMER
PATTERN.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TONIGHT...VFR. THERE COULD BE SOME LOCALIZED FOG DEVELOPMENT
LATE, HOWEVER GIVEN THAT SOME DRYING HAS OCCURRED OUR CONFIDENCE
IN ANY FOG IMPACTING A TERMINAL IS LOW. THEREFORE NO FOG WAS
INCLUDED. WINDS NORTHEAST AT LESS THAN 5 KNOTS, AND EVEN BECOMING
LIGHT AND VARIABLE AT SOME TERMINALS.

MONDAY...VFR. NORTHEAST WINDS 5-10 KNOTS, BECOMING EAST AND
SOUTHEAST IN THE AFTERNOON.

OUTLOOK...
MONDAY NIGHT-WEDNESDAY EARLY AFTERNOON...MOSTLY VFR. ONLY EXCEPTION
WOULD BE POSSIBLE SPOTTY COUNTRYSIDE MVFR FOG EARLY TUESDAY AND
WEDNESDAY MORNINGS.  LIGHT WIND.

LATE WEDNESDAY AFTERNOON-WEDNESDAY NIGHT...MOSTLY VFR WITH A
SMALL CHANCE OF MVFR CONDITION TSTMS OVER PA AND NJ...ESPECIALLY
I78 NORTH. SW WIND GUSTS MOSTLY UNDER 18 KT.

THURSDAY... MOSTLY VFR. WIND TURNING NORTH.

FRIDAY...PROBABLY VFR. EASTERLY OR SOUTHEAST FLOW WITH VFR CIRRUS
OR AC DEVELOPING.

&&

.MARINE...
HIGH PRESSURE BUILDS DOWN FROM THE NORTH THROUGH MONDAY. THIS WILL
MAINTAIN AN ONSHORE FLOW ALSO THROUGH MONDAY, HOWEVER THE PRESSURE
GRADIENT WILL CONTINUE TO RELAX SOUTHWARD. THIS IS EXPECTED TO
RESULT IN LESS GUSTINESS THROUGH TIME, HOWEVER THE PERSISTENT
ONSHORE FLOW WILL KEEP THE SEAS ELEVATED. THIS IS MAINLY ACROSS OUR
SOUTHERN OCEAN ZONES GIVEN A BETTER FETCH AND INITIALLY STRONGER
WINDS. THIS LOOKS TO CONTINUE RIGHT THROUGH MONDAY, THEREFORE THE
SMALL CRAFT ADVISORY FROM LITTLE EGG INLET SOUTHWARD WILL BE
EXTENDED THROUGH AT LEAST THE DAY MONDAY. FARTHER NORTH, THERE IS
RATHER LIMITED BUOY DATA /SEAS AT BUOY 44017 CONTINUE TO BE BELOW 5
FEET/ AND THEREFORE WE ARE ASSUMING SEAS WILL REMAIN UNDER ADVISORY
CRITERIA HERE. THE WINDS ARE ANTICIPATED TO BE BELOW 25 KNOTS FOR
THE NORTHERN ZONES AND DELAWARE BAY.

OUTLOOK...
MONDAY NIGHT...MAY STILL HAVE LINGERING SCA HAZARDOUS 5FT SEAS ON
THE DE WATERS DUE TO THE PERSISTENT NE FETCH CONTG LONGER THAN
PREVIOUSLY ANTICIPATED BUT FOR NOW NO SCA HEADLINE.

TUESDAY-WEDNESDAY MORNING...SUB-SMALL CRAFT ADVISORY CONDITIONS
EXPECTED WITH HIGH PRESSURE ACROSS THE WATERS.

WEDNESDAY AFTERNOON-FRIDAY...LONG PERIOD (AROUND 12 SECOND)
SOUTHEAST SWELLS POSSIBLE AND ARE ASSOCIATED WITH CRISTOBAL...
WHICH SHOULD MAKE A RIGHT HAND TURN SEAWARD OUT TO THE EAST OF THE
CAROLINAS SOMETIME MID OR LATE WEEK. SEE NHC FOR THE TRACK.

&&

.RIP CURRENTS...
THE THREAT OF RIP CURRENTS FOR MONDAY IS HIGH. AN INCREASING
WATER LEVEL, WITH THE NEW MOON OCCURRING AT 1013AM, COMBINED WITH THE
LONG FETCHED ONSHORE FLOW WILL ADD TO THE THREAT OF DANGEROUS RIP
CURRENTS TOMORROW.

WITH THE TROPICAL SYSTEM EXPECTED TO LIFT NORTHEASTWARD /STAYING WELL
OFFSHORE/, LONGER PERIOD SWELLS SHOULD LEAD TO AN ENHANCED RIP
CURRENT RISK LATER THIS WEEK.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...HIGH RIP CURRENT RISK FROM 6 AM EDT MONDAY THROUGH MONDAY
     EVENING FOR NJZ014-024>026.
DE...HIGH RIP CURRENT RISK FROM 6 AM EDT MONDAY THROUGH MONDAY
     EVENING FOR DEZ004.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ452>455.

&&

$$
SYNOPSIS...DRAG
NEAR TERM...GORSE/HEAVENER
SHORT TERM...GORSE
LONG TERM...DRAG
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE
RIP CURRENTS...HEAVENER/DRAG






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