Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 231943
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
343 PM EDT SAT AUG 23 2014

.SYNOPSIS...
HIGH PRESSURE WILL SLIDE SLOWLY SOUTH FROM QUEBEC INCREASING ITS
INFLUENCE ON OUR AREA AS IT BECOMES RIDGED WEST TO EAST FROM THE
MID ATLANTIC STATES INTO THE CENTRAL ATLANTIC EARLY NEXT WEEK. A
COLD FRONT SHOULD SAG SOUTH THROUGH THE MID ATLANTIC STATES LATE
WEDNESDAY OR THURSDAY. THEREAFTER...WE MONITOR TROPICAL DEVELOPMENTS
TO OUR SOUTH WHILE WEAK HIGH PRESSURE PROBABLY PREVAILS OVER THE
MID ATLANTIC STATES AT THE END OF THE WORKWEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A BACKDOOR COLD FRONTAL BOUNDARY WILL CONTINUE WORKING SOUTHEAST
TONIGHT. WITH A PERSISTENT NORTHEAST ONSHORE FLOW CLOUDS AND
SCATTERED SHOWERS HAVE OCCURRED BEHIND THE PASSAGE OF THIS FRONTAL
BOUNDARY WHICH HAS MADE FOR A VERY UNSUMMER LIKE DAY. THE MID
LEVEL DISTURBANCE AND ASSOCIATED VORT MAX WILL CONTINUE TO MOVE
SOUTHEAST OUT OF OUR CWA WITH HIGH PRESSURE BUILDING IN FROM THE
NORTH. SKIES SHOULD CLEAR TONIGHT WITH SOME RELAXATION OF THE
WINDS. THIS MAY RESULT IN SOME PATCHY VALLEY FOG AROUND SUNRISE.
FAVORABLE CONDITIONS WILL BE IN PLACE FOR RADIATIONAL COOLING
TONIGHT AND WENT A TOUCH LOWER THAN MEX/MAV GUIDANCE IN THE
FAVORABLE LOCATIONS NEAR THE JERSEY COASTLINE AND ACROSS MOST OF
PA OUTSIDE OF PHL. ADDITIONAL QPF LOOKS LIGHT AND MAINLY KEPT IT TO
THE DELMARVA BASED ON THE LATEST RADAR TRENDS.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
LOOKS LIKE A GREAT DAY ONCE ANY PATCHY MORNING FOG BURNS OFF
QUICKLY. HIGH PRESSURE SHOULD BE OVER THE REGION THROUGHOUT THE DAY
WITH MOSTLY SUNNY SKIES. THE FLOW WILL CONTINUE TO BE MORE OUT OF
THE EAST SO NOT A RAPID WARMUP UNDERWAY. 850/925 MB TEMPERATURE
ANALYSIS ALONG WITH THE MET AND MAV GUIDANCE SETS SUGGEST HIGHS
AROUND 80 FOR MUCH OF THE REGION, COOLER NORTHWEST. DID TAKE HIGH
TEMPERATURES DOWN A TOUCH ALONG THE COAST.

&&

.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
500 MB: THE STRONG RIDGE IN THE CENTRAL USA WILL BUILD EASTWARD INTO
THE MID ATLANTIC STATES BY MID WEEK. MEANWHILE...WE MONITOR THE
PROBABLE DEVELOPMENT OF A TROPICAL CYCLONE WELL TO OUR SOUTH THIS
COMING WEEK AND ITS POSSIBLE IMPACTS ON OUR FLOW REGIME FOR THE END
OF THE WEEK.

HYDROLOGY: PRESUMING THERE IS NO DIRECT IMPACT OF TROPICAL RAINS
ON OUR AREA LATE THIS COMING WEEK...WE SHOULD BE LOOKING AT A
GENERALLY DRY PERIOD MONDAY THROUGH FRIDAY.

TEMPERATURES: AUGUST...THROUGH THE FIRST 22 DAYS HAS AVERAGED ABOUT
3 DEGREES COOLER THAN NORMAL. THE NEAR NORMAL START TO THIS EXTENDED
PERIOD WILL SEE WARMER THAN NORMAL CALENDAR DAY AVERAGES WEDNESDAY
THROUGH SATURDAY WITH THE WARMEST DEPARTURE OF AT LEAST 5 DEGREES
ABOVE NORMAL CURRENTLY SLATED FOR NEXT THURSDAY.

FORECAST BASIS: UNLESS OTHERWISE NOTED THE LONG TERM PERIOD OF THIS
FORECAST IS GENERALLY BASED ON A 50 50 BLEND OF THE 12Z/23 NAM/GFS
MOS FOR THE PERIOD SUNDAY NIGHT - MONDAY NIGHT...THE 12Z/23 GFS MOS
TUESDAY AND TUESDAY NIGHT...THEN THEREAFTER (WEDNESDAY ONWARD) THE
1523Z/23 WPC GRIDDED GUIDANCE WHICH AT TIMES IS BLENDED 50 50 WITH
THE 12Z/23 MEXMOS. ALL THIS IS EVENTUALLY CHECKED AGAINST THE 12Z/23
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/23 SREF POPS FOR .01 IN 3 HRS THROUGH 00Z
WEDNESDAY AND THEREAFTER THE 12Z/23 GEFS 6HR POPS FOR 0.05


THE DAILIES BELOW...

SUNDAY NIGHT...SEASONABLY COOL. PARTLY CLOUDY TO START AND PROBABLY
MOSTLY CLEAR LATE.  LIGHT WIND.

MONDAY AND TUESDAY...MOSTLY SUNNY AND BEAUTIFUL FOR LATE SUMMER (SCT
CUMULUS ON MONDAY MAY BE BRIEFLY BROKEN DURING THE MIDDAY HOURS; ON
TUESDAY SOME THIN CIRRUS)!

WEDNESDAY...IF THERE IS ANY PATCHY FOG EARLY IN THE DAY IT QUICKLY
DISAPPEARS AND A WARM SUNNY DAY IS FORECAST.  SMALL CHANCE OF A
SHOWER AT NIGHT...MAINLY NE PA AND NW NJ...WHERE SOME CLOUDINESS
SPREADS ACROSS THAT AREA.

THURSDAY...PROBABLY MORE CLOUD COVER IN ASSOCIATION WITH THE COLD
FRONT OR TROPICAL OUTFLOW? LOTS OF UNCERTAINTY FROM HERE ON OUT.
ABOVE NORMAL TEMPS ESPECIALLY HINGED ON WARM MINS IN A MORE
SUMMERY PATTERN THAN WHAT WE`VE EXPERIENCED RECENTLY. COOLING
COASTAL SEA BREEZES.

FRIDAY...ALMOST TOTALLY DEPENDENT ON TROPICAL TRACK BUT PRESUMING
AN OUT TO SEA TRACK...IT SHOULD BE SUMMER WARMTH AND NICE WEATHER.

SATURDAY...DIRECTLY PER THE 1523Z WPC GRIDS WHEN THERE IS POSSIBLY
THE BEST CHANCE OF SHOWERS AND TSTMS AS A NEW TROUGH TRIES TO FORM
IN THE GREAT LAKES.

&&

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

SCATTERED SHOWERS AND A NORTHEAST FLOW HAVE RESULTED IN PERIODIC
EPISODES OF MVFR AND EVEN IFR CEILINGS THIS AFTERNOON. THE MAIN
SYSTEM RESPONSIBLE FOR THIS IS MOVING OUT OF THE REGION. A GRADUAL
IMPROVEMENT THIS EVENING TO VFR IS LIKELY. OVERNIGHT SOME PATCHY FOG
MAY DEVELOP AT RDG, ABE AND MIV AROUND SUNRISE. KEPT VISIBILITIES IN
THE MVFR RANGE ATTM FOR THESE SITES AROUND SUNRISE. VFR TONIGHT AND
SUNDAY AT ALL OTHER SITES. SCATTERED VFR CLOUDS MAY BE AROUND
THROUGH MUCH OF THE DAY SUNDAY WITH A EAST WIND AT OR UNDER 10
KNOTS, SLIGHT CHANCE OF A WIND GUST LEFT OUT OF TAFS ATTM.

OUTLOOK...
SUNDAY NIGHT THROUGH THURSDAY...VFR CONDITIONS EXPECTED WITH ONLY A
SMALL CHANCE OF BRIEF MVFR CONDS FOR A FEW HOURS BEFORE SUNRISE IN
FOG WEDNESDAY MORNING.

&&

.MARINE...
SEAS WILL CONTINUE TO INCREASE TO AROUND FIVE FEET LATE THIS AFTERNOON
WITH CONTINUED WIND GUSTS FROM 15-25 KNOTS. SIMILAR CONDITIONS WILL
CONTINUE THROUGH TOMORROW AFTERNOON AND A SCA REMAINS IN EFFECT
THROUGH 22Z TOMORROW. HOWEVER SEAS MAY RELAX TO AROUND FOUR FEET
FOR THE NORTHERN WATERS ALLOWING THE SCA TO EXPIRE AT 12Z NORTH OF
ATLANTIC CITY.

OUTLOOK...
SUNDAY NIGHT...ANY REMAINING SCA CRITERIA WIND AND SEAS ALONG THE S NJ
AND DE COASTS SHOULD SUBSIDE BELOW SMALL CRAFT ADVISORY EARLY IN THE
EVENING. FOR NOW NO EXTENSION BEYOND WHAT IS POSTED IN THE 317 PM CWFPHI.

MONDAY THROUGH WEDNESDAY...NO MARINE HEADLINES.  VERY GOOD WEATHER
FOR FISHING...MAYBE A LITTLE LIGHT ON THE WIND FOR SAILING.

THURSDAY....TROPICAL CYCLONE RELATED SOUTHEAST LONGER PERIOD SWELLS
MAY BE ARRIVING IN THE DE AND NJ ATLANTIC WATERS PRESUMING A TROPICAL
CYCLONE DEVELOPS AND TRACKS EAST OF THE SE USA COAST.

&&

.RIP CURRENTS...
A MODERATE RISK OF RIP CURRENTS REMAINS TODAY INTO TONIGHT AS SEAS
ARE EXPECTED TO BUILD IN THE PERSISTENT EASTERLY FLOW. THE MODERATE
RISK MAY CONTINUE INTO SUNDAY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR ANZ452>455.
     SMALL CRAFT ADVISORY UNTIL 8 AM EDT SUNDAY FOR ANZ450-451.

&&

$$
SYNOPSIS...DRAG  344
NEAR TERM...GAINES 344
SHORT TERM...GAINES 344
LONG TERM...DRAG 344
AVIATION...DRAG/GAINES 344
MARINE...DRAG/GAINES 344
RIP CURRENTS...344





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