Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

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FXUS61 KPHI 270916
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
416 AM EST TUE JAN 27 2015

.SYNOPSIS...
A STRONG STORM SYSTEM ABOUT 200 MILES OFF THE NEW JERSEY COAST THIS
MORNING WILL MOVE TOWARD THE GULF OF MAINE THIS AFTERNOON AND
TONIGHT BEFORE REACHING THE CANADIAN MARITIMES ON WEDNESDAY. HIGH
PRESSURE BUILDING IN FROM THE OHIO VALLEY WEDNESDAY WILL SETTLE
OVERHEAD WEDNESDAY NIGHT. A CLIPPER SYSTEM WILL MOVE THROUGH THE
REGION THURSDAY NIGHT AND FRIDAY MORNING. HIGH PRESSURE RETURNS
SATURDAY BEFORE ANOTHER LOW PRESSURE SYSTEM MOVES INTO THE EASTERN
UNITED STATES SUNDAY INTO MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE SIGNIFICANT LOW PRESSURE SYSTEM THAT HAS BROUGHT SEVERE WINTER
WEATHER TO THE MIDDLE ATLANTIC AND NORTHEAST IS EAST OF NJ THIS
MORNING AND IT CONTINUES TO DEEPEN. IT WILL MOVE UP EAST OF LONG
ISLAND AND UP TOWARDS NEW ENGLAND LATER TODAY. THE STRONGEST
DYNAMICS/MOISTURE AFFECTED ERN NJ OVERNIGHT WITH THE MOST
SIGNIFICANT WX MOVING JUST TO OUR E. STILL SIGNIFICANT SNOW AND SOME
BLOWING SNOW THIS MORNING FOR THE ERN/NE PARTS OF THE CWA. WE WILL
TAKE DOWN THE BLIZZARD WARNING AND REPLACE IT WITH A WINTER STORM
WARNING FOR SEVERAL HOURS INTO THE MORNING. THE PERIPHERY OF THE
WARNING WILL BE FLANKED BY ADVISORIES WITH LIGHTER AMTS OF SNOW AND
AREAS OF BLOWING/DRIFTING SNOW EARLY TODAY. A FEW OF THE WRN/SRN
AREAS WILL BE DROPPED FROM THE ADVISORIES ISSUED EARLIER. CONDITIONS
IMPROVE THIS AFTERNOON...BUT GUSTY WINDS WILL CONTINUE INTO THE
AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
DEEP LOW PRESSURE WILL CONTINUE TO PULL AWAY TO THE NORTHEAST AS
HIGH PRESSURE BEGINS TO BUILD OVER THE AREA. THE ONLY MENTION OF
PRECIP WILL BE SOME LEFTOVER SNOW SHOWERS THIS EVENING ACROSS THE
SRN POCONOS AND CLOSER TO NYC AREA. SKIES WILL BECOME PARTLY CLOUDY
TO CLR FROM THE SW TO NE AS THE NIGHT PROGRESSES. LOWS TONIGHT WILL
BE IN THE TEENS AND LOW 20S OVER MOST AREAS WITH A FEW SINGLE DIGIT
READINGS OVER THE SRN POCONOS.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THE COASTAL LOW WILL STEADILY WEAKEN ON WEDNESDAY AS IT LIFTS
NORTHEASTWARD THROUGH THE CANADIAN MARITIMES. NORTH-NORTHWESTERLY
FLOW ON THE BACKSIDE OF THE TROUGH WILL GRADUALLY WEAKEN THROUGHOUT
THE DAY AS HIGH PRESSURE BUILDS IN FROM THE OHIO VALLEY. WEDNESDAY
WILL BE 5-10F DEGREES BELOW NORMAL. HOWEVER, DID LEAN ON THE WARMER
SIDE OF GUIDANCE FOR MAX TEMPS UNDER FULL SUNSHINE AND  ADIABATIC
WARMING FROM A DOWNSLOPING COMPONENT TO THE WINDS AS WELL AS LARGE
SCALE SUBSIDENCE IN WAKE OF THE EXITING TROUGH.

RADIATIONAL COOLING SHOULD BE STRONG WITH CLEAR SKIES AND CALM WINDS
OVERNIGHT AS THE CENTER OF HIGH PRESSURE SHIFTS DIRECTLY OVERHEAD.
GIVEN HOW DRY THE AIRMASS IS, THERE IS THE POTENTIAL FOR TEMPS TO
BOTTOM OUT IN THE TEENS FOR THE I-95 URBAN CORRIDOR, ALONG THE COAST
AND IN THE DELMARVA AND SINGLE DIGITS ELSEWHERE. MIN TEMP FORECAST
WAS A BLEND BETWEEN PREVIOUS FORECAST (WHICH WAS THE COLDER THAN ANY
00Z GUIDANCE) AND THE 00Z NAM.

AN ALBERTA CLIPPER IS FORECAST TO TRACK EASTWARD ACROSS THE UPPER
MIDWEST/GREAT LAKES ON THURSDAY BEFORE MOVING THROUGH THE NORTHEAST
STATES ON FRIDAY. ISENTROPIC LIFT AHEAD OF THE ATTENDANT COLD FRONT
AND DPVA WITH THE UPPER SHORTWAVE TROUGH WILL SPREAD INTO
NORTHEASTERN PA LATE IN DAY THURSDAY AND THE REMAINDER OF THE CWA
THURSDAY NIGHT. A PERIOD OF LIGHT SNOW IS LIKELY DURING THIS TIME
WITH THE HIGHEST POPS OVER EASTERN PA AND NORTHERN NJ. THIS SYSTEM
WILL HAVE A BIT MORE MOISTURE (PWAT APPROACH 0.6 INCHES) TO WORK
WITH THAN WHAT TYPICALLY ACCOMPANIES CLIPPERS AS IT IS ABLE TO TAP
INTO LIMITED GULF OF MEXICO MOISTURE. GIVEN THE PROGRESSIVE NATURE
OF THE LOW IS AND THE FACT THAT IT IS NOT FORECAST TO STRENGTHEN
UNTIL IT REACHES THE GULF OF MAINE, SNOWFALL AMOUNTS SHOULD BE
LIGHT: 1-3 INCHES IN THE POCONOS AND EXTREME NW NJ, LESS THAN AN
INCH FARTHER SOUTH AND EAST.

STRONG CAA BEHIND THE COLD FRONT ON FRIDAY. MAX TEMPS IN THE 30S ARE
FORECAST TO OCCUR IN THE AM WITH TEMPS FALLING THROUGHOUT THE
AFTERNOON. BRISK NW WINDS HAVE THE POTENTIAL TO GUST 30-40 MPH
ASSUMING DEEP MIXING IS REALIZED ON LAND. ADDITIONAL SNOW SHOWERS
ARE POSSIBLE IN THE POCONOS.

DAYS 4.5-7 OF THE FORECAST WAS BASED ON THE 05Z/27 WPC ELEMENTS
OF TT/TD/WIND/SKY/POP. WE ADJUSTED THE WPC TEMPS MUCH HIGHER SUN
NIGHT AND A BIT HIGHER MONDAY PER NEW 00Z/27 MODE GUIDANCE
SUGGESTING LOW PRESSURE AND PRECIPITATION IN THIS TIME FRAME.

FRI NIGHT...VERY COLD WITH WIND CHILL ADVISORY POTENTIAL. NW FLOW
BEHIND THE DEPARTING AREA OF LOW PRESSURE SHOULD STILL HAVE GUSTY
WINDS WITH IT THROUGH THE NIGHT.

SATURDAY...FAIR AND VERY COLD. AVERAGE TEMPS ABOUT 15 DEGREES BELOW
NORMAL.

SUNDAY...MODERATING WITH INCREASING CLOUDS DURING THE DAY AND PCPN
OF SOME SORT EXPECTED AT NIGHT. HIGHLY VARIABLE SET OF SOLUTIONS AND
CONFIDENCE ON TEMPS/PTYPE IS WELL BELOW AVERAGE.

MONDAY...MAYBE SOME LEFT OVER PCPN, ESPECIALLY DURING THE MORNING
THEN DRYING OUT AND TURNING COLDER.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

WRAPAROUND SNOW FROM THE COASTAL STORM CONTINUES TO EXPAND TO THE
SOUTH AND WEST ACROSS THE AREA EARLY THIS MORNING. THE TERMINALS ARE
LOCATED ON THE WESTERN PERIPHERY, WHERE LIFT IS WEAKER AND SNOW IS
LIGHTER. HAVE HIGHLIGHTED A 3-4 HOUR TEMPO GROUP EARLY THIS MORNING
FOR IFR VSBYS AT TTN/PNE/PHL/ACY AND MVFR FARTHER SOUTH AND WEST.
THIS SHIELD OF SNOW MAY LINGER OVER THE TERMINALS THROUGH ABOUT 18Z
BUT VSBYS SHOULD GRADUALLY IMPROVE AFTER 15Z AS THE INTENSITY OF THE
SNOW TAPERS OFF. N-NW WINDS 15-20 KT WILL GUST UP TO 25 KT TODAY.
BLSN MAY REDUCE VSBYS LOCALLY AT THE TERMINALS BUT WAS NOT AS
PESSIMISTIC WITH THE VSBYS SINCE THERE IS ONLY A FRACTION OF SNOW ON
THE GROUND AS PREVIOUSLY ANTICIPATED.

VFR LATE THIS AFTN AND TONIGHT. WINDS RELAX A BIT OVERNIGHT.

OUTLOOK...
WEDNESDAY AND WEDNESDAY NIGHT...PRIMARILY VFR. NW WINDS 10-15 KT IN
THE DAY, BECOMING CALM AT NIGHT.

THURSDAY INTO FRIDAY MORNING...VFR TO FOR MUCH OF THURSDAY. LIGHT
SNOW WILL LIKELY SPREAD INTO THE AREA FROM WEST TO EAST THURSDAY
NIGHT BUT MAY REACH ABE/RDG BY LATE AFTERNOON. MVFR/IFR RESTRICTIONS
POSSIBLE WITH THE SNOW. HIGHEST CONFIDENCE IS AT NORTHERN TERMINALS.

FRIDAY AFTERNOON...VFR WITH BLUSTERY NW WIND GUSTING TO 30 KT.

FRI NIGHT...VFR.  GUSTY NW WINDS.

SATURDAY...VFR.

&&

.MARINE...
STORM WARNINGS CHANGED TO GALE WARNINGS FOR NJ WATERS.

DEEP LOW PRESSURE EAST OF THE WATERS WILL CONTINUE TO MOVE NORTHEAST
TODAY. STRONG WINDS WILL CONTINUE TODAY WITH GALE GUSTS EXPECTED AT
LEAST THE FIRST PART OF TODAY. WINDS WILL PROBABLY DROP BACK BELOW
GALE STRENGTH LATER...BUT THE DAY SHIFT CAN MAKE THAT CALL LATER.
SIGNIFICANT SEAS WILL CONTINUE TODAY THEN SUBSIDE TONIGHT.

OUTLOOK...
WEDNESDAY...SCA LIKELY WITH FREEZING SPRAY.

WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...NO MARINE HEADLINES ARE
ANTICIPATED. SOME FREEZING SPRAY POSSIBLE WEDNESDAY NIGHT.

FRIDAY- NEAR GALE-FORCE GUSTS BEHIND A CLIPPER SYSTEM.

FRI NIGHT: POSSIBLE LEFTOVER NW GALE FORCE WIND GUSTS.

SATURDAY...SCA CONDITIONS POSSIBLE.

&&

.TIDES/COASTAL FLOODING...
THE JUST-PASSED HIGH TIDE ALONG THE NJ/DEL SHORE PRODUCED MINOR
TIDAL FLOODING AND SOME MAY BE ONGOING ACROSS LOWER DEL BAY. WE NO
LONGER EXPECT ANY SERIOUS TIDAL FLOODING TO OCCUR AND THE COASTAL
FLOOD WARNING WILL BE DROPPED. THE SUBSEQUENT TIDES WILL LIKELY NOT
BE SIGNIFICANT...SINE WINDS WILL BECOME OFFSHORE TODAY AND REMAIN
THAT WAY FOR TONIGHT AND TUE.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR PAZ055-062-
     071-103>106.
NJ...WINTER STORM WARNING UNTIL 3 PM EST THIS AFTERNOON FOR NJZ001-
     007>010-012>015-020-025-026.
     WINTER WEATHER ADVISORY UNTIL NOON EST TODAY FOR NJZ018-019-
     027.
DE...NONE.
MD...NONE.
MARINE...GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ430-431-
     450>455.

&&

$$
SYNOPSIS...KLEIN
NEAR TERM...O`HARA
SHORT TERM...O`HARA
LONG TERM...DRAG/KLEIN
AVIATION...DRAG/KLEIN
MARINE...DRAG/KLEIN
TIDES/COASTAL FLOODING...O`HARA






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