Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 170010
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
810 PM EDT THU OCT 16 2014

.SYNOPSIS...
AN AREA OF LOW PRESSURE WILL MEANDER AROUND TO OUR NORTH DURING THE
NEXT COUPLE OF DAYS, THEN THE NEXT COLD FRONT IS SCHEDULED TO MOVE
THROUGH EARLY SATURDAY. HIGH PRESSURE THEN BRIEFLY BUILDS INTO OUR
AREA LATE SUNDAY INTO MONDAY. ANOTHER COLD FRONT SHOULD ARRIVE LATE
MONDAY INTO TUESDAY, THEN SLOWLY EASE OFFSHORE AS LOW PRESSURE
DEVELOPS ALONG IT. HIGH PRESSURE WILL THEN START TO BUILD INTO THE
OHIO VALLEY WEDNESDAY AND THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
757 PM ESTF UPDATE: EXPANDED THE RISK OF SHOWERS PER RADAR...MAINLY
LEHIGH VALLEY...EAST EDGE OF THE POCONOS INTO NW NJ FOR THE NEXT
HOUR OR TWO AND WITHDREW THE THUNDER OPTION.

ADJUSTED TEMPS DOWN FASTER THIS EVENING.

AT 930 PM THE OVERNIGHT FORECAST...WILL PROBABLY ADD PATCHY FOG FOR
MANY COUNTRYSIDE AREAS, ESPECIALLY WHERE IT RAINED THIS EVENING.
IT SHOULD BE A SHALLOW PATCHY FOG. OTHERWISE CLEAR SKIES PRIOR TO
THE DYING BATCH OF SHOWERS AND BAND OF CLOUDS CROSSING E PA AND THEN
VARIABLE CLOUDINESS AFTER THE CURRENT BAND OF CLOUDS IN PA PASSES
EASTWARD.

KRDG THIS EVENING RECEIVED .38; KABE TRACE KMPO .02

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
THE UPPER LOWS TROUGH SHOULD ROTATE THROUGH OUR AREA BY EARLY FRIDAY
MORNING. DRIER CONDITIONS LOOK TO BE IN PLACE AND WHILE THERE WILL
BE SOME CLOUDS AROUND, PLENTY OF SUNSHINE WILL BE IN STORE FOR OUR
AREA.

TEMPERATURES WILL RISE INTO THE 70S DURING THE DAY, 60S ACROSS THE
NORTHERN TERRAIN.

&&

.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
THE OVERALL SYNOPTIC PATTERN IS COMPRISED OF AN INITIAL CLOSED LOW
WELL TO OUR NORTH, HOWEVER SHORT WAVE ENERGY DIVING SOUTHEASTWARD
AMPLIFIES THE WESTERN AND SOUTHERN SIDE ACROSS THE GREAT LAKES
FRIDAY NIGHT. THIS FEATURE THEN AMPLIFIES SOME MORE ACROSS THE EAST
SATURDAY, WITH THE AXIS PROBABLY SHIFTING TO OUR EAST SUNDAY. WHILE
THIS UPPER-LEVEL TROUGH MAY LIFT OUT DURING SUNDAY AND MONDAY,
ANOTHER SHARPENING UPPER-LEVEL TROUGH ARRIVES INTO THE NORTHEAST AND
MID ATLANTIC MONDAY NIGHT AND TUESDAY. THE UPPER-LEVEL FLOW IS
GENERALLY FORECAST TO AMPLIFY QUITE A BIT WITH A RIDGE IN THE
PLAINS. THIS SHOULD ALLOW THE TROUGH IN THE EAST TO CLOSE OFF AS WE
GO THROUGH TUESDAY AND WEDNESDAY. DEPENDING ON HOW AMPLIFIED IT
BECOMES, IT MAY HANG AROUND THROUGH THURSDAY AS WELL ALTHOUGH SOME
EASTWARD SHIFT SHOULD OCCUR. THE PASSAGE OF A COUPLE OF COLD FRONTS
WILL DELIVER MUCH COOLER AIR ACROSS THE AREA STARING SUNDAY, THEN WE
WATCH FOR THE POTENTIAL FOR A WESTERN ATLANTIC STORM TO DEVELOP NEXT
WEEK THAT COULD BE CLOSE ENOUGH TO THE COAST. WE USED A MODEL BLEND
FOR FRIDAY NIGHT THROUGH SUNDAY, THEN THE 12Z WPC GUIDANCE
THEREAFTER. SOME ADJUSTMENTS WERE THEN MADE AFTER ADDITIONAL
COLLABORATION WITH OUR SURROUNDING OFFICES.

FOR FRIDAY NIGHT AND SATURDAY...AN AMPLIFYING UPPER-LEVEL TROUGH IS
FORECAST TO SLIDE ACROSS THE GREAT LAKES AND OHIO VALLEY. AN
ASSOCIATED SURFACE FRONT SHOULD BE CLEARING OUR AREA SATURDAY
MORNING. THERE COULD BE A FEW SHOWERS WITH THIS MAINLY NEAR OUR
NORTHWESTERN ZONES SATURDAY, THEN CAA STRENGTHENS ESPECIALLY LATE AS
A CYCLONIC FLOW REGIME IS MAINTAINED. IT APPEARS THAT SATURDAY WILL
BE THE LAST OF THE MILDER DAYS FOR THE REMAINDER OF THE FORECAST
PERIOD AS THE CHILLY AIR DEFINITELY ARRIVES AT NIGHT. AS LOW
PRESSURE TRACKS TO OUR NORTH, THE PRESSURE GRADIENT IS FORECAST TO
TIGHTEN SATURDAY AND THIS COMBINED WITH THE INCREASING CAA WILL
PROMOTE DEEPER MIXING. THEREFORE, BREEZY CONDITIONS ARE ANTICIPATED
DURING THE DAY BEFORE SUBSIDING SOME AT NIGHT.

FOR SUNDAY AND MONDAY...AN UPPER-LEVEL TROUGH IS FORECAST TO SHIFT
ACROSS THE AREA SUNDAY, THEN RELOAD FROM THE WEST MONDAY. A
TIGHTENING PRESSURE GRADIENT SUNDAY WITH DECENT MIXING SHOULD RESULT
IN BREEZY TO PERHAPS WINDY CONDITIONS, THEN SUBSIDE DURING SUNDAY
NIGHT. ANOTHER SURFACE FRONT IS THE FORECAST TO CROSS OUR AREA
MONDAY NIGHT WITH LOW PRESSURE STARTING TO DEVELOP ALONG IT. A MUCH
COOLER AIRMASS WILL ADVECT INTO OUR AREA DURING THIS TIME AS A
RESULT OF THE AMPLIFYING UPPER-LEVEL TROUGH. AS SURFACE HIGH
PRESSURE BUILDS INTO THE MID ATLANTIC SUNDAY NIGHT INTO MONDAY,
LIGHTER WINDS COMBINED WITH A CHILLY AIRMASS MAY ALLOW FOR SOME
FROST DEVELOPMENT EARLY MONDAY ESPECIALLY NORTH AND WEST I-95. THIS
WILL DEPEND THOUGH ON ANY CLOUD COVER AS A SYSTEM IS FORECAST TO BE
APPROACHING LATE FROM THE NORTHWEST. SOME WEAK WAA AHEAD OF THIS
FEATURE MAY TOSS ENOUGH CLOUDS THIS FAR EAST TO KEEP TEMPERATURES UP
SOME OR BOTTOM OUT EARLY BEFORE SOME RECOVERY. SOME SLIGHT CHC TO
LOW CHC POPS WERE BROUGHT IN FROM WEST TO EAST MONDAY NIGHT WITH
THE NEXT SYSTEM.

FOR TUESDAY AND WEDNESDAY...THE POSITIONING OF THE STRENGTHENING
CLOSED LOW WILL GENERALLY DETERMINE THE TRACK OF A WESTERN ATLANTIC
STORM SYSTEM. THIS IS THE INITIAL SURFACE LOW THAT DEVELOPS ON THE
EASTBOUND COLD FRONT AS THE THERMAL GRADIENT TIGHTENS. THERE IS
SOME MODEL DISAGREEMENT WITH THIS SYSTEM ESPECIALLY WITH THE
DETAILS, HOWEVER SOME ENSEMBLE MEMBERS DO HAVE A COASTAL LOW TUCKED
IN CLOSER TO THE COAST. WHILE THIS IS OCCURRING, HIGH PRESSURE
BUILDS ACROSS THE GREAT LAKES REGION AND TOWARD OUR AREA. THIS
ALLOWS FOR A NORTHERLY FLOW OF CHILLY AIR ACROSS THE REGION TO
CONTINUE. GIVEN THE UNCERTAINTY ABOUT THE SPECIFICS THIS
FAR OUT, WE WENT WITH THE 12Z WPC GUIDANCE WHICH NOW LEANS MORE
TOWARD SOME AFFECTS FROM THE CLOSING UPPER-LEVEL LOW, WESTERN
ATLANTIC SURFACE LOW AND POSSIBLE WRAPAROUND. THUS WE INCREASED THE
POPS INTO THE CHC RANGE.

FOR THURSDAY...THE IDEA OF A RATHER ROBUST CLOSED LOW WOULD TEND TO
SLOW THE EASTWARD PROGRESSION OF THE SURFACE FEATURES. THEREFORE
WHILE THE CLOSED LOW IS FORECAST TO SHIFT EAST SOME DURING THIS TIME
FRAME, THERE MAY BE STILL SOME BACKLASH ON ITS WESTERN FLANK. THIS
WILL BE HIGHLY DEPENDENT ON THE LOCATION OF THE LARGE CLOSED LOW AND
ITS ASSOCIATED SURFACE LOW AS IT EJECTS NORTHEASTWARD PROBABLY OFF
THE SOUTHEASTERN NEW ENGLAND COAST. THEREFORE, WE FAVORED THE 12Z
WPC GUIDANCE WITH LOW CHC POPS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

THROUGH TONIGHT...VFR SCT-BKN AOA 4000 FT. SCT LIGHT SHOWERS MAINLY
NW NJ AND FAR NE PA WILL DISSIPATE BY 0130Z. LIGHT WIND. PATCHY FOG
IN THE COUNTRYSIDE AND THE 00Z TAFS HAVE THE EXPECTATIONS.

FRIDAY...VFR CONDITIONS EXPECTED ACROSS THE TERMINALS. WINDS WILL
INCREASE AROUND LATE MORNING AND BE WEST SOUTHWEST AROUND 10 KNOTS.
WINDS GUSTS BELOW 20 KNOTS.

OUTLOOK...
FRIDAY NIGHT...VFR. SOUTHWEST WINDS DIMINISHING TO 5 KNOTS OR LESS.

SATURDAY AND SUNDAY...MAINLY VFR. WEST TO NORTHWEST WINDS AROUND 15
KNOTS WITH GUSTS TO 25 KNOTS BOTH DAYS, HOWEVER DIMINISHING SOME
EACH NIGHT.

MONDAY AND TUESDAY...VFR OVERALL MONDAY, HOWEVER THEN POSSIBLE
SUB-VFR CONDITIONS DEVELOPING TUESDAY WITH SOME RAIN. LIGHT
SOUTHWEST WINDS MONDAY, BECOMING NORTHEASTERLY LESS THAN 10 KNOTS
TUESDAY.

&&

.MARINE...
A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS REMAINS IN EFFECT ON THE
OCEAN WATERS THROUGH SATURDAY.

WINDS WILL REMAIN BELOW 25 KNOTS THROUGH FRIDAY. SEAS WILL CONTINUE
TO REMAIN ELEVATED AS SWELLS FROM DISTANT MAJOR HURRICANE GONZALO
CONTINUE TO MOVE INTO OUR AREA.

OUTLOOK...
FRIDAY NIGHT...WHILE WINDS SHOULD BE BELOW SMALL CRAFT ADVISORY
CRITERIA, SWELLS ON THE OCEAN FROM FAR DISTANT HURRICANE GONZALO
SHOULD KEEP SEAS WITHIN SMALL CRAFT ADVISORY CRITERIA.

SATURDAY AND SUNDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE ON DELAWARE BAY DUE TO INCREASING WEST AND THEN NORTHWEST
WINDS MAINLY STARTING SATURDAY NIGHT. ON THE OCEAN, A COMBINATION OF
LEFTOVER SWELLS FROM GONZALO AND A STRONGER WEST THEN NORTHWEST FLOW
SHOULD KEEP SMALL CRAFT CONDITIONS GOING. SINCE THE STRONGER
WINDS /UP TO 30 KNOTS/ LOOK TO NOT ARRIVE UNTIL SATURDAY NIGHT,
THE SMALL CRAFT ADVISORY /EXTENDED TO 22Z SATURDAY/ WAS CHANGED
TO CONVEY HAZARDOUS SEAS. A REGULAR ADVISORY SHOULD THEN BE NEEDED
FOR SATURDAY NIGHT AND SUNDAY WITH STRONGER CAA AND BETTER MIXING.
THE WINDS AND SEAS DECREASE SUNDAY NIGHT.

MONDAY AND TUESDAY...THE CONDITIONS ARE ANTICIPATED TO BE BELOW
ADVISORY CRITERIA.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 6 PM EDT
     SATURDAY FOR ANZ450>455.

&&

$$
SYNOPSIS...GORSE
NEAR TERM...DRAG  810
SHORT TERM...MEOLA
LONG TERM...GORSE
AVIATION...DRAG/GORSE 810
MARINE...GORSE/MEOLA





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