Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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000
FXUS61 KPHI 081656
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1156 AM EST MON FEB 8 2016

.SYNOPSIS...
A STRONG AREA OF LOW PRESSURE OFFSHORE OF THE EAST COAST WILL
MOVE NORTHEAST AND FARTHER OUT TO SEA TODAY. ANOTHER AREA OF LOW
PRESSURE IS FORECAST TO DEVELOP TONIGHT NEAR THE SOUTHERN MID-
ATLANTIC COAST. AFTER THIS LOW QUICKLY MOVE OUT TO SEA EARLY
TUESDAY, A WEAKER AREA OF LOW PRESSURE MAY ORGANIZE TUESDAY
AFTERNOON AND NIGHT. AN ARCTIC COLD FRONT WILL APPROACH FROM THE
NORTHWEST WEDNESDAY BEFORE MOVING THROUGH THE REGION WEDNESDAY
NIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST THURSDAY. A CLIPPER
SYSTEM IS EXPECTED TO PASS TO OUR NORTH LATE FRIDAY. IN ITS WAKE,
A REINFORCING SHOT OF ARCTIC AIR WILL MAKE IT INTO THE REGION FOR
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE WINTER WEATHER ADVISORY FOR MIDDLESEX, MONMOUTH, AND OCEAN
COUNTIES HAS BEEN CANCELLED AS THE MAIN PRECIPITATION HAS MOVED
OFFSHORE AND WILL CONTINUE TO PULL AWAY FROM THE AREA. THERE COULD
BE SOME LIGHT RAIN OR SNOW SHOWERS FOR ANOTHER HOUR OR TWO, BUT
MOST AREAS SHOULD NOW BE PRECIPITATION FREE FOR THE REMAINDER OF
THE DAYTIME HOURS.

WINDS WILL CONTINUE TO GUST 20-30 MPH NEAR THE COAST THROUGH MUCH
OF THE DAY. INLAND SHOULD REMAIN GUST FREE, BUT A STEADY NORTH-
NORTHEAST BREEZE SHOULD CONTINUE.

TEMPERATURES SHOULD STAY FAIRLY STEADY, IF NOT DROP SLIGHTLY
THROUGH THE DAY FOR SOME AREAS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
PRECIPITATION, GENERALLY SNOW OR A RAIN AND SNOW MIX WILL START TO
MOVE IN FROM THE SOUTHWEST DURING THE EVENING HOURS AS THE LEADING
TROUGH LIFTS INTO THE REGION. THE MAIN UPPER LEVEL LOW WILL REMAIN
WELL WEST OF THE REGION THROUGH THIS TIME, SO DO NOT EXPECT THE
HEAVIEST SNOW TO BE THROUGH THE OVERNIGHT HOURS, AND THE MODELS HAVE
IN FACT TRENDED SLIGHTLY DRIER THROUGH THIS PERIOD. EVEN SO, THE
SOUTHERN HALF OF THE REGION COULD SEE AS MUCH AS 4 INCHES OF SNOW IF
MESOSCALE BANDS DEVELOP EARLY ENOUGH.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
THE SECONDARY COASTAL LOW THAT DEEPENS RAPIDLY OFF THE NC OUTERBANKS
MONDAY NIGHT IS EXPECTED TO MOVE TOO FAR OFFSHORE ON TUESDAY TO
DIRECTLY IMPACT US. HOWEVER, WE AREN`T OUT OF THE WOODS AS MODELS
ARE SHOWING THE PRIMARY SURFACE LOW REORGANIZING AS IT MOVES OFF THE
DELMARVA COAST ON TUESDAY. THIS SEEMS LIKE A PLAUSIBLE SCENARIO
SINCE THE INITIAL MILLER-B LOW IS EXPECTED TO MOVE WELL OUT TO
SEA (LEAVING SOME SEPARATION BETWEEN THE TWO) AND THERE LOOKS TO
BE ANOTHER MID-LEVEL SHORTWAVE TROUGH ROTATING AROUND THE UPPER
LOW THAT WOULD CONTRIBUTE TO HEIGHT FALLS AND COASTAL
CYCLOGENESIS. IN THESE TYPES OF SETUPS, ENHANCED FRONTOGENETICAL
LIFT AND MESOSCALE BANDING IS FAVORED ON THE NWRN SIDE OF THE LOW.
THE 00Z GUIDANCE HAD COME INTO BETTER AGREEMENT AND SHOWS THE
POTENTIAL FOR MESOSCALE BANDING IN THEIR MASS/THERMAL FIELDS THAT
PRODUCES A RELATIVELY NARROW WEST-EAST ORIENTED BAND OF HEAVIER
QPF OVER THE NRN DELMARVA/SERN PA/SRN NJ. PARTIAL THICKNESSES
IMPLY ALL SNOW. HOWEVER, THE CURRENT FORECAST OF HIGHS IN THE
UPPER 30S FOR THESE AREAS OF CONCERN IMPLY THE LOWER BOUNDARY
LAYER IS MARGINALLY SUPPORTIVE OF SNOW. THERE IS CERTAINLY A
POTENTIAL THAT SOME RAIN MIXES IN AND/OR SNOW HAS A TOUGH TIME
ACCUMULATING...BUT ONLY IF THE INTENSITY OF THE PRECIP IS LIGHT.
IF THE HEAVIER SNOW DOES MATERIALIZE, THEN DYNAMICAL COOLING
SHOULD BE ENOUGH TO OVERCOME THIS ISSUE.

AFTER COORDINATION WITH WPC AND NEIGHBORING WFOS, WE DECIDED IT WAS
BEST TO ISSUE A WINTER STORM WATCH FOR FAR SERN PA, NRN DELMARVA AND
SRN NJ. THE WHOLE AREA IN THE WATCH WILL LIKELY NOT SEE WARNING
CRITERIA SNOWFALL (AND SOME MAYBE SIGNIFICANTLY LESS) BUT THIS IS
WHERE THE GREATEST POTENTIAL FOR 5 OR MORE INCHES OF SNOWFALL
EXISTS IN A RATHER NARROW SWATH SOMEWHERE APPROXIMATELY AS FAR
NORTH AS PHILADELPHIA AND AS FAR SOUTH AS DOVER. ANOTHER
CHALLENGE WITH THIS EVENT IS TRYING TO PINPOINT THE TIMING OF THE
HEAVIER SNOW. THE WATCH GOES STARTS LATE TONIGHT AND CONTINUES 28
HOURS THROUGH TUESDAY NIGHT. WE ARE NOT EXPECTING A LONG DURATION
EVENT BUT WE WENT WIDE IN TIME TO ACCOUNT FOR THE UNCERTAINTY IN
WHEN THE HEAVIER SNOW BAND DEVELOPS. ONE CAMP OF MODELS INDICATE
IT WILL OCCUR LATE TONIGHT INTO TUESDAY MORNING WHILE OTHER
CLUSTER FAVORS LATER TUESDAY AFTERNOON AND NIGHT.

FARTHER NORTH INTO NERN PA AND NWRN NJ, WHERE THE POSSIBILITY FOR
HEAVIER SNOW IS LOOKING LESS LIKELY AT THIS POINT, LIGHT SNOW MAY
ONLY ACCUMULATE AN INCH OR TWO TUESDAY-TUESDAY NIGHT. HOWEVER,
WE`LL STILL NEED TO MONITOR FOR THE POSSIBILITY OF THE HEAVIER
SNOW BAND SHIFTING NORTHWARD. VERY FEW SCENARIOS CAN BE RULED OUT
AT THIS POINT.

THE UPPER LOW EVENTUALLY OPENS UP AND THE WAVE PASSES THRU THE
AREA ON WEDNESDAY. A KICKER SYSTEM WILL QUICKLY FOLLOW WEDNESDAY
NIGHT/EARLY THURSDAY. WE WILL KEEP A LOW CHANCE FOR SNOW SHOWERS
DURING THIS TIME BUT ADDITIONAL SNOWFALL ACCUMULATIONS WOULD BE
MINOR. THIS SECOND DISTURBANCE WILL ALSO BE ACCOMPANIED BY THE
A COLD FRONTAL PASSAGE. IN ITS WAKE, THE SOUTHERN FRINGE OF
ARCTIC AIR WILL MAKE ITS WAY INTO THE MID ATLANTIC. TEMPS THURSDAY
AND FRIDAY WILL STRUGGLE TO GET ABOVE FREEZING IN THE COASTAL
PLAIN AND LIKELY REMAIN IN THE 20S NORTH AND WEST OF THE FALL
LINE.

A CLIPPER SYSTEM IS EXPECTED TO PASS TO OUR NORTH LATE FRIDAY. A
SECONDARY WAVE OF LOW PRESSURE MAY DEVELOP FARTHER SOUTH TOWARD THE
BASE OF THE LARGE-SCALE TROUGH AND ON THE SOUTHERN FRINGE OF THE
POLAR AIRMASS. FOR THE MOST PART, MODELS ARE SUPPRESSING THE TRACK
OF THE LOW TO OUR SOUTH AND DEEPENING IT TOO FAR OFFSHORE TO BRING
THE DEEPER ATLANTIC MOISTURE BACK INTO OUR AREA. HOWEVER, THE 00Z
ECMWF, WITH SUPPORT FROM SOME OF ITS ENSEMBLE MEMBERS, ARE SHOWING A
DEEPER AND MORE NORTHERN SYSTEM, WHICH COULD BRING YET ANOTHER
ROUND OF AT SNOW TO OUR REGION.

A REINFORCING SHOT OF ARCTIC AIR WILL MAKE IT INTO THE REGION FOR
THE WEEKEND. TEMPERATURES COULD BE 15-20F BELOW NORMAL NEXT WEEKEND
AND WIND CHILL VALUES BELOW ZERO IN THE HIGHER ELEVATIONS.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.

TAFS REMAIN VARIABLE BETWEEN VFR/UPPER END OF MVFR CONDITIONS
WITH CIGS BETWEEN 2,500-3,500 FEET. LATER THIS AFTERNOON AND
EVENIG, AN APPROACHING TROUGH WILL BRING LOWER CEILINGS, AND
EVENTUALLY LOWER VISIBILITIES WITH SNOW. LOWER CEILINGS COULD
START TO MOVE IN BETWEEN 21 AND 00Z, BUT DO NOT EXPECT THE SNOW TO
MOVE IN UNTIL AFTER 00Z. ONCE SNOW BEGINS TO MOVE IN, EXPECT
WIDESPREAD IFR CONDITIONS.

OUTLOOK...
TUESDAY AND TUESDAY NIGHT...PERIODS OF SNOW EXPECTED. THE SNOW MAY
MIX WITH RAIN AT MIV AND ACY DURING THE DAY TUESDAY ESPECIALLY AT
TIMES WHEN IT IS LIGHTER. THERE IS STILL PLENTY OF UNCERTAINTY
REGARDING THE TIMING AND OVERALL IMPACTS AT THE AIRPORTS BUT WE CAN
SAY THAT CONFIDENCE HAS INCREASED THAT A NARROW BAND OF HEAVIER SNOW
WILL DEVELOP SOMETIME DURING THE PERIOD NEAR THE ILG-PHL-ACY
CORRIDOR. EXPECT WIDESPREAD MVFR/IFR CONDS AND THE POSSIBILITY FOR
LIFR IF THE HEAVIER SNOW BAND DEVELOPS.

WEDNESDAY...LEFTOVER SNOW SHOWERS WILL TAPER OFF FROM WEST TO EAST
DURING THE DAY, THEN CONDITIONS IMPROVE TO VFR. BREEZY WLY WINDS
GUSTING TO 25 KT.

THURSDAY...VFR AND BREEZY NW WINDS GUSTING AOA 30 KT. CONFIDENCE IS
HIGH.

FRIDAY...CURRENTLY FORECASTING VFR BUT WE ARE WATCHING THE POTENTIAL
FOR ANOTHER STORM SYSTEM TO DEVELOP NEAR THE MID-ATLANTIC COAST AND
BRING MORE SNOW INTO THE AREA. CONFIDENCE IS LOW.

&&

.MARINE...
THE GALE WARNING HAS BEEN CANCELLED FOR THE OCEAN AS WINDS HAVE
FALLEN BELOW WARNING LEVELS. A SMALL CRAFT ADVISORY HAS BEEN
ISSUED IN ITS PLACE AS WINDS MAY GUST AROUND 25 KNOTS, BUT SEAS
REMAIN HIGH WITH THE NORTHEAST FETCH.

WINDS WILL BEGIN TO INCREASE AGAIN LATE TONIGHT/EARLY TUESDAY
MORNING AHEAD OF THE NEXT LOW MOVING IN FROM THE WEST.

OUTLOOK...
TUESDAY AND WEDNESDAY...ANOTHER AREA OF LOW PRESSURE WILL DEVELOP
OFF THE MID-ATLANTIC COAST. SCA CONDITIONS EXPECTED WITH HAZARDOUS
SEAS AND PERIODS OF 25 KT GUSTS. THERE COULD BE A TEMPORARY LULL IN
THE WINDS ON TUESDAY CLOSE TO WHERE THE LOW DEVELOPS.

THURSDAY AND FRIDAY...SOLID SCA CONDITIONS EXPECTED. GALES ARE
CERTAINLY A POSSIBLE WITH GUSTY NW WINDS AND STEEP LAPSE RATES
BEHIND A COLD FRONT.

&&

.TIDES/COASTAL FLOODING...
UPDATE TO ADD ATLANTIC, SOUTHEASTERN BURLINGTON, AND OCEAN
COUNTIES TO THE COASTAL FLOOD WARNING FOR BOTH TIDE CYCLES THIS
MORNING.

HIGH PRESSURE WILL ANCHOR OVER EASTERN QUEBEC/LABRADOR WHILE LOW
PRESSURE PASSING OFFSHORE WELL TO THE SOUTHEAST UNDERGOES
EXPLOSIVE DEEPENING THROUGH TODAY. WITH THE AFOREMENTIONED HIGH
REMAINING TO OUR NORTH, A BROAD AREA OF LOW PRESSURE WILL DEVELOP
OFF THE OUTER BANKS TONIGHT AND PASS OFFSHORE SOUTHEAST OF OUR
REGION DURING THE DAY TOMORROW. THESE TWO SYSTEMS WILL MAINTAIN AN
ONSHORE FLOW ALONG THE COAST THRU TUESDAY, WITH ONLY A BRIEF PAUSE
THIS AFTERNOON AND VERY EARLY TONIGHT, AS THE PRESSURE GRADIENT
RELAXES BETWEEN SYSTEMS.

ADDING TO THE TIDAL FLOODING POTENTIAL, ASTRONOMICAL TIDES WILL
BE HIGH DUE TO THE NEW MOON TODAY.

FOR MUCH OF THE JERSEY SHORE, WE ALREADY SAW A LARGE DEPARTURE
WITH THE LOW TIDE EARLIER, AND WINDS HAVE INCREASED SHARPLY AND
ARE EXPECTED TO CONTINUE THROUGH THE HIGH TIDE CYCLE. THUS, MODEL
GUIDANCE AND A LOCAL REGRESSION PROGRAM INDICATE THAT A DEPARTURE
OF OVER 2 FEET IS POSSIBLE WITH THE NEXT HIGH TIDE, OR JUST ENOUGH
TO REACH MODERATE FLOODING THRESHOLDS. WITH THE CONTINUED
NORTHEAST FLOW AND HIGH WAVE ACTION, EXPECT THAT IT COULD BE A
SIMILAR STORY FOR TONIGHT`S HIGH TIDE, THOUGH THAT IS THE LOWER OF
THE ASTRONOMICAL TIDES. THUS THE WARNING INCLUDES BOTH HIGH TIDE
CYCLES TODAY. CONTINUED THE WATCH FOR TOMORROW`S HIGH TIDE CYCLE.

FOR THE FAR SOUTHERN NJ SHORE AND THE DELAWARE COASTS...WITH HIGH
ASTRONOMICAL TIDES, WE EXPECT A SURGE OF 1 TO 2 FT THIS MORNING.
WE HAVE HIGH CONFIDENCE IN WIDESPREAD MINOR COASTAL FLOODING. WE
HAVE ALSO TEMPERED DOWN THE HIGH-BIASED ET AND ESTOFS GUIDANCE DUE
TO A RESIDUAL BIAS OF NEARLY 1 FOOT IN SPOTS. A COASTAL FLOOD
ADVISORY HAS BEEN ISSUED FOR THIS MORNING`S HIGH TIDE ALONG THE
SOUTHERN NJ AND DE OCEANFRONT, AS WELL AS DELAWARE BAY. THERE IS A
BIT MORE UNCERTAINTY ON WHETHER WE REACH THE MINOR THRESHOLD AT
REEDY POINT, WHICH IS LARGELY DEPENDENT ON EKMAN TRANSPORT IN A
NORTHEAST FLOW, BUT WE EXPECT IT TO BE CLOSE NONETHELESS.

THE COASTAL FLOOD ADVISORY CONTINUES FOR THE CENTRAL AND SOUTHERN
NJ AND DE OCEANFRONT FOR THIS EVENING`S HIGH TIDE.

FOR THE TUESDAY MORNING HIGH TIDE, A MORE EASTERLY COMPONENT/LONGER
FETCH TO THE WIND WILL HAVE A GREATER IMPACT ALONG THE ENTIRE COAST,
INCLUDING DELAWARE BAY, AND PORTIONS OF THE TIDAL DELAWARE. WE AGREE
WITH THE STRONGER GFS WINDS, ESPECIALLY GIVEN THE SYNOPTIC SETUP.
THE MAIN UNCERTAINTY IS REGARDING A BROAD LOW PRESSURE/TROUGH MOVING
NORTHEASTWARD ALONG THE COAST, WHICH MAY ALLOW WINDS TO QUICKLY
RELAX NEAR THE TIME OF HIGH TIDE, PARTICULARLY DELMARVA AND FAR
SOUTHERN NJ. NEVERTHELESS, ASIDE FROM A BRIEF LULL IN THE FLOW
MONDAY AFTERNOON AND VERY EARLY MONDAY NIGHT, WE`LL HAVE HAD NEARLY
48 HOURS DURATION OF ONSHORE FLOW, WHICH WILL MAKE FOR HIGHER TIDAL
DEPARTURES COMPARED TO MONDAY MORNING, IN ADDITION TO THE
ASTRONOMICALLY HIGHER TIDES. IN TERMS OF GUIDANCE, WE SIDED MORE
WITH THE HIGHER ETSS SURGE OF 2 TO 2.5 FEET, EVEN CONSIDERING THE
AFOREMENTIONED RESIDUAL. A COASTAL FLOOD WATCH REMAINS IN EFFECT FOR
THE TUESDAY MORNING HIGH TIDE FOR THE NJ AND DE OCEANFRONT WITH
THE HIGHEST CONFIDENCE IN WIDESPREAD MODERATE COASTAL FLOODING FOR
CENTRAL AND NORTHERN NJ. ELSEWHERE, WIDESPREAD MINOR COASTAL
FLOODING IS ANTICIPATED, PERHAPS UP TO PHILADELPHIA, GIVEN THE
MORE EASTERLY FLOW UP DELAWARE BAY. FOR THESE AREAS, A COASTAL
FLOOD ADVISORY WILL LIKELY BE NEEDED.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY
     NIGHT FOR PAZ070-071-101-102.
NJ...COASTAL FLOOD WARNING UNTIL 10 PM EST THIS EVENING FOR
     NJZ012>014-020-022-025>027.
     COASTAL FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY
     AFTERNOON FOR NJZ012>014-020>027.
     COASTAL FLOOD ADVISORY UNTIL 4 AM EST TUESDAY FOR NJZ021-023-
     024.
     COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     NJZ016.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY
     NIGHT FOR NJZ016>023-027.
DE...COASTAL FLOOD WATCH FROM LATE TONIGHT THROUGH TUESDAY
     AFTERNOON FOR DEZ002>004.
     COASTAL FLOOD ADVISORY UNTIL 4 AM EST TUESDAY FOR DEZ002>004.
     COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     DEZ001.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY
     NIGHT FOR DEZ001-002.
MD...WINTER STORM WATCH FROM LATE TONIGHT THROUGH LATE TUESDAY
     NIGHT FOR MDZ008-012-015.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ450>455.

&&

$$
SYNOPSIS...KLEIN
NEAR TERM...JOHNSON/ROBERTSON
SHORT TERM...JOHNSON
LONG TERM...KLEIN
AVIATION...JOHNSON/KLEIN
MARINE...JOHNSON/KLEIN/ROBERTSON
TIDES/COASTAL FLOODING...


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