Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 062047
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
347 PM EST SAT FEB 6 2016

.SYNOPSIS...
LOW PRESSURE IS FORECAST TO DEVELOP OFF THE SOUTHEAST COAST THIS
WEEKEND AND TRACK NORTHEASTWARD LATE SUNDAY INTO MONDAY. ANOTHER
LOW PRESSURE SYSTEM IS FORECAST TO DEVELOP IN ITS WAKE NEAR THE
MID- ATLANTIC COAST MONDAY NIGHT INTO TUESDAY. ARCTIC HIGH
PRESSURE IS THEN EXPECTED TO BUILD IN FROM THE NORTH AND WEST
DURING THE LATTER PART OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
HIGH PRESSURE REMAINS ACROSS THE AREA TONIGHT, WHICH WILL KEEP THE
WEATHER DRY. OTHER THAN SOME CIRRUS CLOUDS, NOT MUCH TO AFFECT THE
AREA. WINDS WILL BECOME LIGHT AND VARIABLE OVERNIGHT. THIS WILL
ALLOW FOR TEMPERATURES TO FALL OVERNIGHT AND COOL QUITE EFFICIENTLY.
SHOULD BE ANOTHER FROSTY MORNING SUNDAY.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
AFTER ANOTHER FROSTY START, TEMPERATURES WILL RISE SEVERAL DEGREES
WARMER THAN SATURDAY AND END UP A FEW DEGREES ABOVE NORMAL. CLOUDS
WILL BEGIN TO THICKEN AND LOWER DURING THE AFTERNOON FROM SOUTH TO
NORTH AS A SYSTEM APPROACHES FROM THE SOUTH. HOWEVER, WE EXPECT THE
FORECAST TO REMAIN PRECIPITATION FREE THROUGH THE DAYTIME HOURS.


&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THERE ARE 2 SYSTEMS TO WATCH DURG THE EXTENDD PD. THE FIRST IS A
STRONG CSTL LOW THAT EMERGES OFF THE SERN CST ON SUN. THE VAST
MAJORITY OF THE MDL GUID KEEPS THIS LOW OFF THE ATLC CST, WITH
MINIMAL IMPACT ON OUR AREA. THIS IS A VERY STRONG LOW AND BEARS
WATCHING AS IT MAKES ITS CLOSEST APPROACH ON MON. THE NAM AND CMC IS
IMPLYING A MORE WWD TRACK THAT WOULD HAVE AT LEAST SOME IMPACTS ON
CSTL AREAS OF NJ. THE MORE WWD SOLN HAS SEEMINGLY WON OUT THIS
SEASON, WITH THE JAN BLIZZARD AND EVEN THE SYS EARLIER THIS WEEK,
SO THIS SOLN IS NOT TERRIBLY FAR FETCHED. HOWEVER, THE
PREPONDERANCE OF THE MDL GUID CONTINUES TO BE AGAINST IT. IF IT
WERE TO PRECIP MON AFTN, IT WOULD BE TOO WARM IN MANY AREAS FOR
SNOW.

THE NEXT SYS WILL THEN DEVELOP SOMEWHERE OFF THE MID-ATLC CST MON
NIGHT. MDL GUID CONTINUES TO STRUGGLE TO RESOLVE THE DETAILS OF
THIS SYS AND CONFIDENCE REMAINS MUCH BELOW AVERAGE. THIS LOW WILL
MOVE NEWD THRU TUE. THE ECMWF MADE A PRONOUNCED EWD SHIFT THIS
CYCLE AND IS MUCH DRIER AS A RESULT ON TUE. THE GFS SHIFTED
SLIGHTLY FURTHER E, BUT REMAINS WETTER. THE CMC IS THE WETTEST
SOLN OF ALL. ANOTHER FACTOR TO CONSIDER IS TEMPS. THE GFS HAS HAD
A WARM BIAS WITH BOTH THE JANUARY BLIZZARD AND THE SYSTEM EARLIER
THIS WEEK, BUT ITS TEMPS ARE FAIRLY CLOSE TO THE ECMWF. THAT WOULD
SUGGEST FOR AREAS FROM THE I-95 CORRIDER S AND EWD SFC TEMPS WOULD
BE ABV FREEZING ON TUE. WHILE THERE COULD BE SOME DIABATIC
COOLING, IF THINGS GET WARM ENOUGH THERE COULD BE MIXING OR EVEN A
CHANGE OVER OR SNOW THAT FALLS AND DOESN`T ACCUMULATE, ESPECIALLY
DUG THE DAYLIGHT HOURS.

BASED ON ALL THIS UNCERTAINTY, ESPECIALLY THE EWD SHIFT OF THE
ECMWF (DEPSITE ITS LESS THAN STELLAR PERFORMANCE THIS WINTER), SEE
NO REASON TO INCREASE SNOW AMTS AT THIS TIME AND WILL ONLY MAKE
SOME MINOR TWEAKS.

KEY TAKEAWAYS HERE, WHILE THERE IS STILL ALOT OF UNCERTAINTY WITH
THIS STORM, JANUARY 23RD THIS IS NOT. A COUPLE OF INCHES IS PSBL.
SOME PLACES CUD GET MORE, SOME LESS.

AS THIS LOW PULLS AWAY, CANADIAN HIGH PRES IWLL BUILD INTO THE
MID-SECTION OF THE COUNTRY AND EVENTUALLY BUILD EWD. TEMPS WILL
STRUGGLE TO CLIMB OUT OF THE 30S BY THE END OF THE WEEK.



&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD WITH ONLY CIRRUS
CLOUDS EXPECTED THROUGH MOST OF SUNDAY. CLOUDS WILL BEGIN TO THICKEN
AND LOWER DURING THE AFTERNOON FROM SOUTH TO NORTH AS A SYSTEM
APPROACHES FROM THE SOUTH, BUT AGAIN REMAIN VFR THROUGH THE DAY.
SOUTHWEST WINDS 5-10 KNOTS THIS AFTERNOON WILL BECOME LIGHT AND
VARIABLE/CALM EVERYWHERE OVERNIGHT AS HIGH PRESSURE REMAINS ACROSS
THE AREA. WINDS WILL PICK UP AGAIN OUT OF THE NORTH TO NORTHEAST
DURING THE DAY SUNDAY.

OUTLOOK...
SUN NIGHT...VIRTUALLY ALL OF THE GUID CONTINUES TO KEEP THE
STRONG STORM OFFSHORE. HOWEVER, ANY WESTWARD SHIFT IN THE TRACK
MAY BRING A PERIOD OF LIGHT RAIN AND/OR SNOW TO EASTERN TERMINALS.
OTHERWISE, VFR CONDS ARE EXPECTED. MDT CONFIDENCE.

MON AND TUE...LOWER THAN AVERAGE CONFIDENCE THIS PD, AS A STORM
SYS MAY DEVELOP NR THE MID-ATLC CST AND PRECIP MAY OVERSPREAD THE
AREA MONDAY AFTERNOON AND EVENING. THERE ARE UNCERAINTIES WRT THE
TRAK OF THIS SYS AS WELL AS TEMPS ON TUE. PRECIP SHUD BEGIN AS
RAIN LATER MON AND SHUD CHANGE OVER TO SNOW MON NIGHT. ON TUE,
PRECIP COULD CHANGE BACK OVER TO RAIN ESPECIALLY FROM THE I-95
CORRIDOR SE, BUT HERE IS WHERE THE GREATEST UNCERTAINTY LIES.
POTENTIAL FOR IFR RESTRICTIONS ESPECIALLY ONCE IT CHANGES OVER TO
SNOW. HIGH UNCERTAINTY EXISTS ALSO FOR SNOW AMTS.

WED...IMPROVING CONDITIONS. MAINLY VFR ALTHOUGH THERE IS A SMALL
RISK FOR A BRIEF RESTRICTION WITH A PASSING SNOW SHOWER. MDT
CONFIDENCE.

THURSDAY...VFR.  HIGH CONFIDENCE.

&&

.MARINE...
SUB-ADVISORY CONDITIONS WILL PREVAIL ACROSS THE WATERS TONIGHT AS
HIGH PRESSURE CONTINUES TO AFFECT THE AREA. WINDS WILL BEGIN TO
INCREASE FROM THE SOUTH TO THE NORTH DURING THE AFTERNOON SUNDAY AS
THE PRESSURE GRADIENT BEGINS TO TIGHTEN AHEAD OF THE APPROACHING
SYSTEM FROM THE SOUTH. A SMALL CRAFT ADVISORY IS NOW IN EFFECT
STARTING AT 1 PM SUNDAY, THOUGH THE WINDS WILL LAG A COUPLE OF HOURS
ACROSS THE FAR NORTHERN WATERS.

OUTLOOK...
SUN NIGHT AND MONDAY...THE GALE WATCH WILL REMAIN IN EFFECT. THERE
IS A LOT OF UNCERTAINTY WITH RESPECT TO THE TRACK OF THE LOW AND,
THEREFORE WE DID NOT OPT TO RAISE TO A GLW ATTM. IT WILL EITHER BE
A VERY STRONG SCA OR MARGINAL GLW.

MON NIGHT THROUGH THU...ANOTHER AREA OF LOW PRESSURE WILL DEVELOP
OFF THE MID-ATLANTIC COAST. AN EXTENDED PERIOD OF SCA CONDITIONS
LIKELY DURING THIS TIME. IT COULD POTENTIAL REACH GALE FORCE LATE
WED INTO THU BUT UNCERTAINTY IS VERY HIGH REGARDING THE STRENGTH
OF THE WINDS.

&&

.TIDES/COASTAL FLOODING...
...WE ARE WATCHING TWO POTENTIAL COASTAL FLOOD EVENTS NEAR
THE MONDAY MORNING HIGH TIDE AND TUESDAY MORNING HIGH TIDE..

THE FLOW WILL BECOME ONSHORE SUNDAY AFTERNOON AS HIGH PRESSURE
ANCHORS OVER SOUTHEAST CANADA AND LOW PRESSURE DEVELOPS OFF THE
CAROLINAS. THIS AREA OF LOW PRESSURE IS EXPECTED TO PASS WELL
SOUTHEAST OF OUR REGION. WITH THE AFOREMENTIONED HIGH REMAINING
TO OUR NORTH, ANOTHER AREA OF LOW PRESSURE WILL DEVELOP OFF THE
OUTERBANKS OF NORTH CAROLINA MONDAY NIGHT AND PASS SOUTHEAST OF
OUR REGION DURING THE DAY TUESDAY.

THESE TWO SYSTEMS WILL MAINTAIN AN ONSHORE FLOW ALONG THE COAST
TO VARYING DEGREES SUNDAY THRU TUESDAY. ASTRONOMICAL TIDES WILL
BE HIGH TO BEGIN WITH, GIVEN THE NEW MOON ON MONDAY, REACHING
THEIR PEAKS DURING THE MONDAY AND TUESDAY MORNING HIGH TIDES.

FOR THE MONDAY MORNING HIGH TIDE, THE THREAT OF COASTAL FLOODING
WILL BE HIGHEST ALONG THE NORTHERN NJ COAST, WHERE THE GREATEST
COMPONENT OF ONSHORE FLOW WILL BE PRESENT. GIVEN THE SHORT
DURATION OF STRONGER ONSHORE FLOW, THE WIND BACKING FROM THE
NORTHEAST TO NORTH /MORE OFFSHORE/ AS WE APPROACH HIGH TIDE,
AND CONTINUED UNCERTAINTY REGARDING THE STORM TRACK, CONFIDENCE
REGARDING IMPACTS IS LOW. AT THIS TIME, THERE IS THE POTENTIAL
FOR AT LEAST MINOR COASTAL FLOODING, PARTICULARLY THE NORTHERN
NJ COAST.

REGARDING THE TUESDAY MORNING HIGH TIDE, A MORE ROBUST AREA OF
LOW PRESSURE IS EXPECTED TO TRACK CLOSER TO THE COAST, WITH A
STRONGER ONSHORE FLOW. ASIDE FROM A BRIEF LULL IN THIS FLOW LATE
MONDAY, WE`LL HAVE HAD NEARLY 48 HOURS DURATION OF ONSHORE FLOW,
WHICH WILL MAKE FOR POSITIVE TIDAL DEPARTURES TO BEGIN WITH.
IN ADDITION, A MORE EASTERLY WIND WILL MAKE FOR A LONGER FETCH
IN TERMS OF BUILDING WAVE ACTION. BUT THERE IS CONSIDERABLE
UNCERTAINTY REGARDING THE EVOLUTION OF THIS LOW AND ASSOCIATED
LOW-LEVEL JET, SO AGAIN OUR CONFIDENCE REGARDING IMPACTS IS
LOW. AT THIS TIME, THERE IS THE POTENTIAL FOR MORE WIDESPREAD
MINOR COASTAL FLOODING.

PLEASE STAY TUNED TO LATER FORECASTS AND POSSIBLE HEADLINES.



&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
     ANZ450>455.
     SMALL CRAFT ADVISORY FROM 1 PM TO 8 PM EST SUNDAY FOR
     ANZ450>455.
     SMALL CRAFT ADVISORY FROM 8 PM SUNDAY TO 6 AM EST MONDAY FOR
     ANZ430-431.

&&

$$
SYNOPSIS...NIERENBERG
NEAR TERM...ROBERTSON
SHORT TERM...ROBERTSON
LONG TERM...NIERENBERG
AVIATION...NIERENBERG/ROBERTSON
MARINE...NIERENBERG/ROBERTSON
TIDES/COASTAL FLOODING...FRANCK


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