Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 061353
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
953 AM EDT FRI MAY 6 2016

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MOVE INTO OUR AREA FROM THE SOUTHEAST
LATER TODAY, THEN LINGER THROUGH SATURDAY BEFORE DISSIPATING. A COLD
FRONT WILL MOVE THROUGH SUNDAY MORNING, FOLLOWING BY HIGH PRESSURE
SUNDAY NIGHT INTO MONDAY BEFORE MOVING OFFSHORE. A WARM FRONT LIFTS
NORTH ACROSS OUR AREA DURING TUESDAY, THEN STALLS IN OUR AREA
WEDNESDAY INTO THURSDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SOME HEAVIER SHOWERS HAVE BEEN TRAVERSING THE REGION THIS MORNING
WITH SCATTERED SHOWERS CONTINUING ACROSS THE AREA. EXPECT THE
HEAVIER RAIN TO CONTINUE TO PUSH TO THE WEST-SOUTHWEST AND OUT OF
THE AREA THIS MORNING. LIGHT TO MODERATE RAIN SHOWERS WILL
CONTINUE THROUGH THE REST OF THE DAY WITH SOME TAPERING OFF
EXPECTED FROM EAST TO WEST LATER IN THE DAY.

SPC HAS EXPANDED THE AREA OF GENERAL THUNDER SO HAVE INCLUDED A
SLIGHT RISK THROUGH THIS AFTERNOON ACROSS THE ENTIRE AREA. CONSIDERABLE
INSTABILITY ALOFT SUGGEST POTENTIAL FOR ISOLATED THUNDER/ASSOCIATED
SMALL HAIL WITH VERY STEEP MID LVL LAPSE RATES AND LOW WBZ NEAR
6000 FT. NOT SURE WHAT WILL TRIGGER THE THUNDER EXCEPT SFC
CONVERGENCE WITH THE LOW COMING ASHORE AND PERHAPS SOME AFTERNOON
SFC HEATING NEAR THE APPROACHING LOW OVER DE. TEMPS MAY BE SEVERAL
DEGREES COLDER THAN YDY I95 NWWD.

A GUSTY NE WIND FOR A TIME THIS MORNING NEAR 20 MPH EXCEPT GUSTS
MIDDAY AND EARLY AFTERNOON MONMOUTH AND OCEAN COUNTIES MAY APPROACH
35 MPH (SEE HRRR GUSTS AS A BAND OF STRONGER WIND WELL NORTH OF
THE LOW CENTER SHIFTS WESTWARD WITH LOW ALONG THE S SHORE OF LI).

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HAVE UNCERTAINTY REGARDING TIMING OF ANY SHOWERS AND ANY LEFTOVER
ISOLATED EVENING TSTMS (SE PA/S NJ). CONFIDENCE ON WHAT OCCURS
AND WHERE, IS BELOW AVERAGE. IN PART THIS IS DUE TO RECENT LOSS
OF CONFIDENCE IN GFS QPF FCSTS. NE WIND DIMINISHING THIS EVENING
AND BECOMING LIGHT SOUTHERLY ON THE DELMARVA, POSSIBLY EVEN TO
I95.

FOG MAY BECOME A PROBLEM TONIGHT WITH A LIGHT WIND IN THE MIDST
OF VERTICALLY STACKED MOIST LOW PRESSURE SYSTEM.

FCST WAS A 50 50 BLEND OF THE 00Z/6 GFS/NAM MOS.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE SYNOPTIC SETUP IS COMPRISED OF AN INITIAL CLOSED LOW CENTERED
OVER OUR AREA SATURDAY, HOWEVER THIS FEATURE OPENS UP DURING
SATURDAY AS IT SHIFTS EASTWARD. THIS OCCURS AS A STRONG SHORT WAVE
TROUGH DIVES SOUTHEASTWARD ACROSS THE GREAT LAKES SATURDAY AND INTO
THE NORTHEAST SATURDAY NIGHT AND SUNDAY. THE NEW TROUGH AMPLIFIES
ACROSS THE NORTHEAST SUNDAY BEFORE GRADUALLY LIFTING OUT MONDAY. A
WEAK RIDGE THEN ARRIVES FOR EARLY NEXT WEEK WITH A SURFACE WARM
FRONT ALSO MOVING THROUGH. THE WARM FRONT HOWEVER MAY END UP
STALLING IN OUR VICINITY WEDNESDAY AND THURSDAY AS ENERGY SHEARS
EASTWARD ALONG IT. GIVEN THE PATTERN CHANGE, MUCH WARMER AIR IS
EXPECTED TO ARRIVE NEXT WEEK WITH THIS CHANGE STARTING OVER THE
WEEKEND ESPECIALLY DURING SUNDAY. THE EXTENT OF THE WARMING THOUGH
NEXT WEEK WILL DEPEND ON THE PLACEMENT OF THE FRONTAL BOUNDARY AS IT
MAY MEANDER ACROSS OUR CWA AND ALSO PRECIPITATION CHCS. WE USED A
MODEL BLEND APPROACH FOR SATURDAY THROUGH SUNDAY NIGHT, THEN BLENDED
IN THE 00Z WPC GUIDANCE THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE
FOLLOWING ADDITIONAL COLLABORATION WITH OUR NEIGHBORING OFFICES.

FOR SATURDAY AND SUNDAY...THIS TIME FRAME BEGINS WITH A CLOSED LOW
RIGHT OVER OUR AREA SATURDAY MORNING, HOWEVER THIS FEATURE WILL OPEN
UP AND SHIFT EASTWARD DURING THE COURSE OF THE DAY. THIS WILL BE DUE
TO A KICKER SHORT WAVE TROUGH AMPLIFYING ACROSS THE GREAT LAKES
REGION. A CORE OF -20C TO -24C AIR AT 500 MB IS OVER OUR AREA
SATURDAY MORNING, HOWEVER THIS MODIFIES THROUGH THE DAY AS THE
TROUGH OPENS UP AND SHIFTS TO OUR EAST. THE PRESENCE OF COLD AIR
ALOFT COMBINED WITH SOME LIFT FROM THE CLOSED LOW SHOULD RESULT IN
MAINLY SCATTERED SHOWERS SATURDAY ESPECIALLY INLAND. THE FLOW IS
LIGHT UNDER THE CLOSED LOW THEREFORE SHOWERS SHOULD BE SLOW MOVERS.
SINCE THE AIRMASS IS WARMING DURING THE COURSE OF THE DAY, THIS MAY
MITIGATE THE INSTABILITY POTENTIAL. IT APPEARS ANY INSTABILITY IS
MARGINAL AND THEREFORE THUNDER WAS NOT ADDED FOR SATURDAY ATTM. AS
WE LOSE THE CONTINUOUS ONSHORE FLOW COMPONENT AND THE TROUGH ALOFT
WEAKENING THROUGH SATURDAY, THERE SHOULD BE AT LEAST SOME BREAKS OF
SUNSHINE.

AN AMPLIFYING TROUGH FROM THE GREAT LAKES THEN STARTS TO NEAR OUR
AREA TOWARD DAYBREAK SUNDAY. LOW PRESSURE TRACKING TO OUR NORTH WILL
PULL A COLD FRONT INTO OUR AREA LATE SATURDAY NIGHT AND THIS FRONT
MAY MOVE IN A BIT FASTER. THERE APPEARS TO BE A PLUME OF DEEPER
MOISTURE IN COMBINATION WITH FORCING FOR ASCENT TO DRIVE SOME SHOWERS
/PERHAPS A BAND OF SHOWERS/ ACROSS MUCH OF OUR AREA. THE STRONGEST
FORCING MAY GLANCE OUR NORTHERN AREAS AND THEREFORE THE HIGHEST POPS
WERE PLACED THERE LATER AT NIGHT. ANY SHOWERS SHOULD QUICKLY SHIFT
OFFSHORE SUNDAY MORNING AS THE COLD FRONT ALSO EXITS, THEN DRIER AIR
AND BETTER MIXING WILL PROMOTE SUNSHINE FINALLY RETURNING FOR THE
AFTERNOON. IT WILL BE A BIT BREEZY THOUGH SUNDAY IN THE WAKE OF THE
COLD FRONT AS LOW-LEVEL LAPSE RATES STEEPEN AND THE PRESSURE
GRADIENT TIGHTENS. WE WENT A BIT WARMER THAN MOS FOR SUNDAY
ESPECIALLY FOR THE COASTAL PLAIN GIVEN DOWNSLOPING FLOW. HIGH
PRESSURE THEN STARTS TO ARRIVE SUNDAY NIGHT ALLOWING THE WINDS TO
DIMINISH.

FOR MONDAY AND TUESDAY...SOME WEAK RIDGING ARRIVES DURING MONDAY,
ALLOWING SURFACE HIGH PRESSURE TO BE OVER OUR CWA TO START BUT IT
LOOKS TO SHIFT OFFSHORE LATER MONDAY. THIS WILL ALLOW A SOUTHERLY
FLOW TO BECOME BETTER ESTABLISHED AND WITH DOWNSTREAM WAA
INCREASING, A WARMER TIME FRAME IS EXPECTED. THE WAA WILL BE USHERED
IN VIA A WARM FRONT AS IT CROSSES THE AREA DURING TUESDAY, AND THERE
COULD BE ENOUGH LIFT TO PRODUCE SOME SHOWERS OR A THUNDERSTORM
MAINLY TUESDAY AFTERNOON AND NIGHT. THE FORECAST CHALLENGE IS THAT
THIS FRONT MAY THEN STALL IN OUR AREA AS ENERGY INITIALLY SHEARS
EASTWARD ALONG IT. THIS SHEARING ENERGY COULD PRODUCE SOME
CONVECTION.

FOR WEDNESDAY AND THURSDAY...THE FORECAST CHALLENGE IS WITH THE
FRONTAL ZONE AS IT LOOKS TO BE DRAPED ACROSS OUR AREA, HOWEVER A
TROUGH AMPLIFYING ACROSS NEW ENGLAND WEDNESDAY MAY PUSH THE FRONT
FARTHER SOUTHWARD. THIS SOUTHWARD PUSH COULD BE ENHANCED AS HIGH
PRESSURE MAY BUILD DOWN SOME FROM NORTHERN NEW ENGLAND. A TROUGH IN
THE MIDWEST HOWEVER PUSHES SURFACE LOW PRESSURE UP THE OHIO VALLEY
WEDNESDAY NIGHT INTO THURSDAY, WITH DOWNSTREAM WAA AND SOUTHERLY
FLOW ALLOWING THE BOUNDARY TO START LIFTING NORTHWARD SOME AS A WARM
FRONT. THIS TIME FRAME SHOULD BE ON THE WARMER SIDE, HOWEVER THIS
WILL ULTIMATELY DEPEND ON THE POSITIONING OF THE FRONTAL BOUNDARY
AND ANY CONVECTION THAT OCCURS. GIVEN THE UNCERTAINTY, WE BLENDED
THE 00Z WPC GUIDANCE IN WITH CONTINUITY AND THEN MADE SOME TWEAKS.

&&

.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

TODAY...CIGS GENERALLY VARIABLE 600-1600 FT VSBY 1-4 MI IN SHOWERY
RAINS DURING THE MORNING WITH POSSIBLE IMPROVING CONDITIONS
DURING THE AFTERNOON. ISOLATED TSTM POSSIBLE DURING THE MORNING
KACY/KMIV AND THEN DURING THE AFTN ELSEWHERE. TSTMS NOT IN TAF DUE
TO LOW CONFIDENCE AND ISOLATED NATURE. NE WIND...GUSTS 15-23 KT FOR
A TIME LATER THIS MORNING-MIDDAY.

TONIGHT... MVFR/IFR CONDS IN ST/FOG, POSSIBLE CLUSTERS OF SHOWERS.
DIMINISHING NE WIND THIS EVENING NEAR AND N OF I78. OTHERWISE LIGHT
WIND TRENDING SOUTH.

OUTLOOK...
SATURDAY...MVFR/IFR CEILINGS IN THE MORNING SHOULD IMPROVE TO VFR IN
THE AFTERNOON. MAINLY SCATTERED SHOWERS ARE ANTICIPATED WHICH CAN
LOCALLY REDUCE THE VISIBILITY FOR A TIME, THEN A BAND OF SHOWERS
ARRIVES LATE AT NIGHT WITH A COLD FRONT. SOUTHEASTERLY WINDS MAINLY
LESS THAN 10 KNOTS, BECOMING SOUTHWEST AT NIGHT.

SUNDAY...BRIEF MVFR CONDITIONS IN THE MORNING WITH SOME SHOWERS AS A
COLD FRONT MOVES THROUGH, OTHERWISE VFR. WEST TO NORTHWEST WINDS
INCREASE TO 12-18 KNOTS WITH GUSTS TO 25 KNOTS, THEN DIMINISH AT
NIGHT.

MONDAY AND TUESDAY...VFR, THEN POSSIBLY SOME MVFR DURING TUESDAY
WITH A CHANCE OF SHOWERS AS A WARM FRONT MOVES THROUGH. WESTERLY
WINDS AROUND 10 KNOTS MONDAY, BECOMING LIGHT AT NIGHT THEN SHIFTING
TO SOUTHERLY TUESDAY.

&&

.MARINE...
LETTING THE SCA ON THE DELAWARE BAY EXPIRE AS WINDS ARE IN THE
MID TEENS AND NOT EXPECTED TO INCREASE MUCH THROUGH THE REST OF
THE DAY.

SCA CONTINUES OCEAN WATERS THROUGH TONIGHT, ESPECIALLY DUE TO
SEAS.

SMALL CHANCE WE WILL NEED TO UPGRADE TO A SHORT FUSE SHORT DURATION
GALE ANZ450-451 FOR THE PERIOD 16Z-21Z. CONFIDENCE IN UPGRADING
WAS LESS THAN 80 PCT SO HAVE HELD OFF FOR NOW.

FOG MAY BECOME A MARINE HAZARD LATER THIS FRIDAY NIGHT.

OUTLOOK...
SATURDAY...THE WINDS ARE ANTICIPATED TO BE LIGHT AS A CLOSED LOW
INITIALLY OVERHEAD WEAKENS AND THEN SHIFTS EASTWARD. THE SEAS MAY BE
RIGHT AT 5 FEET TO START ESPECIALLY ACROSS THE NORTHERN WATERS BUT
OVERALL THE CONDITIONS SHOULD BE TRENDING BELOW ADVISORY CRITERIA.
THEREFORE WE DID NOT EXTEND THE ADVISORY ATTM.

SUNDAY...WEST TO NORTHWEST WINDS TURN GUSTY TO AROUND 20 KNOTS WITH
SEAS AT OR BELOW 4 FEET. IT IS POSSIBLE WINDS GUST TO 25 KNOTS
NEARSHORE, HOWEVER OVERALL CONDITIONS ARE ANTICIPATED TO BE BELOW
ADVISORY CRITERIA.

MONDAY AND TUESDAY...SUB-ADVISORY CONDITIONS ARE ANTICIPATED DESPITE
SOME INCREASE IN A SOUTHERLY WIND MONDAY AND THEN AGAIN LATER
TUESDAY.

&&

.TIDES/COASTAL FLOODING...
PLEASE SEE THE HAZARD CFW STATEMENT FOR THE PARTICULARS RELATING
TO EACH AREA.

PHL: TIDAL DE ADVY EXPIRED BUT MAY NEED A NEW ONE TO BE ISSUED
THIS AFTERNOON FOR THE EARLY SATURDAY MORNING HIGH TIDE CYCLE.
CONFIDENCE IN EXCEEDING THE ADVY THRESHOLD WAS NOT QUITE
CATEGORICAL ON THIS SHIFT.

REEDY POINT UPPER DE BAY, LOWER TIDAL DE LINKED: REISSUED FOR LATE
THIS EVENING, SINCE CONFIDENCE IS CATEGORICAL THAT IT WILL REOCCUR,
ESPECIALLY BECAUSE THE FUNNELED ENE FLOW THIS MORNING TURNS LIGHT
SOUTH THIS EVENING.

NJ/DE ATLC COASTS: NO CHANGE IN THE PREVIOUS WARNING. THE TIDAL
SURGE IS EXPECTED TO STAY AROUND 1 TO 1.5 FEET TODAY IN THE
CONTINUING NORTHEASTERLY FLOW. THE THURSDAY EVENING HIGH TIDE SAW
MANY OBSERVING SITES EITHER JUST REACH OR FALL JUST SHY OF
MODERATE FLOODING THRESHOLDS. WE ARE FORECASTING MINOR TIDAL
FLOODING AROUND THIS MORNING`S HIGH TIDE AND MODERATE FLOODING
AROUND THIS FRIDAY EVENING`S HIGH TIDE. RATHER THAN CARRY MULTIPLE
HEADLINES, WE CONTINUED WITH THE COASTAL FLOOD WARNING TO COVER
BOTH HIGH TIDE CYCLES. MINOR TIDAL FLOODING MAY LINGER WITH THE
HIGH TIDE CYCLES ON SATURDAY.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR NJZ012>014-
     020>027.
     COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
     SATURDAY FOR NJZ016.
DE...COASTAL FLOOD WARNING UNTIL 1 AM EDT SATURDAY FOR DEZ002>004.
     COASTAL FLOOD ADVISORY FROM 10 PM THIS EVENING TO 2 AM EDT
     SATURDAY FOR DEZ001.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR ANZ450>455.

&&

$$
SYNOPSIS...GORSE
NEAR TERM...DRAG/MEOLA
SHORT TERM...DRAG
LONG TERM...GORSE
AVIATION...DRAG/GORSE
MARINE...DRAG/GORSE/MEOLA
TIDES/COASTAL FLOODING...



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