Area Forecast Discussion
Issued by NWS Mt. Holly, NJ

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KPHI 250552
AFDPHI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
1252 AM EST SUN JAN 25 2015

.SYNOPSIS...
STRONG LOW PRESSURE OFF THE NEW ENGLAND COAST WILL TRACK INTO THE
CANADIAN MARITIMES THROUGH TONIGHT. A WEAK AREA OF HIGH PRESSURE
WILL BUILD ACROSS THE AREA LATER TONIGHT INTO SUNDAY. A LOW PRESSURE
SYSTEM WILL THEN MOVE ACROSS THE OHIO VALLEY AND MID ATLANTIC
REGIONS SUNDAY NIGHT INTO MONDAY. ANOTHER STRONGER LOW WILL FORM OFF
THE EAST COAST MONDAY, THEN MOVE UP ALONG THE OFFSHORE WATERS
MONDAY NIGHT AND TUESDAY. HIGH PRESSURE BUILDS IN FOR THE MIDWEEK
PERIOD, THEN ANOTHER LOW MAY AFFECT THE REGION ON THURSDAY.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A DEEP SURFACE LOW OFF THE NEW ENGLAND COAST WILL TRACK INTO THE
CANADIAN MARITIMES THROUGH THE OVERNIGHT. MEANWHILE, THE WATER VAPOR
IMAGERY SHOWS THE MAIN TROUGH AXIS HAS SHIFTED TO OUR EAST.

THE DRYING THAT OCCURRED ALLOWED THE CLOUDS TO DISSIPATE FROM WEST
TO EAST, HOWEVER ADDITIONAL CLOUDS ARE ARRIVING FROM THE WEST
WHICH IS BEING TRAPPED UNDER AN INVERSION. AS A RESULT, THE CLOUDS
WERE INCREASED SOME FOR A TIME FROM WEST TO EAST. OTHER THAN A FEW
FLURRIES POSSIBLE IN THE POCONOS, ANY SNOW SHOWERS OR DRIZZLE SHOULD
REMAIN TO THE WEST WHERE THE BETTER MOISTURE IS LOCATED ALONG WITH
SOME INCOMING WEAK WAA. THE WEST TO NORTHWEST FLOW HAS INCREASED
SOME AND THIS WILL HELP TO DRY OUT THE GROUND MOISTURE A BIT.
HOWEVER AS TEMPERATURES DROP TO AND BELOW FREEZING OVERNIGHT
COMBINED WITH A COLD GROUND, WILL LEAD TO UNTREATED WET SURFACES
REFREEZING.

THE HOURLY GRIDS WERE ADJUSTED BASED ON THE LATEST OBSERVATIONS,
WHICH INCLUDED SHOWING A BIT HIGHER TEMPERATURES TO START. THE
LAMP/LAV GUIDANCE WAS BLENDED IN TO HELP WITH THE TEMPERATURE AND
DEW POINT TRENDS. NO MAJOR CHANGES WERE MADE TO THE LOW TEMPERATURES
ATTM.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
OVERALL, A RELATIVELY QUIET DAYTIME IS EXPECTED FOR SUNDAY, WITH
SOME BRIEF, WEAK RIDGING OVER THE AREA. THE MAIN FEATURE TO WATCH ON
THE HORIZON WILL BE A CLIPPER LOW TRACKING INTO THE OHIO VALLEY BY
LATE IN THE DAY. FOR MOST OF THE DAY, INCREASING CLOUDINESS WITH
CONTINUED WEST-NORTHWEST WINDS ARE EXPECTED, BUT SOME LIGHT PRECIP
MAINLY IN THE FORM OF LIGHT SNOW/RAIN IS ANTICIPATED GOING INTO THE
EVENING FOR OUR SOUTHERN AND WESTERN ZONES WITH THE APPROACHING
CLIPPER SYSTEM. MAINLY LIGHT RAIN IS EXPECTED AT THE ONSET, THOUGH,
FOR THE CENTRAL TO SOUTHERN DELMARVA BEFORE TEMPERATURES FALL AND
PRECIP INTENSITY INCREASES LATER SUNDAY NIGHT. A BLEND OF MET/MAV
GUIDANCE WITH CONTINUITY WAS USED FOR DAYTIME MAX TEMPERATURES, AND
WE ANTICIPATE HIGHS FOR MUCH OF THE FORECAST AREA TO RANGE FROM THE
MIDDLE 30S TO THE LOWER 40S.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
SUN NIGHT THRU MONDAY...A CLIPPER SYSTEM WITH A DECENT AMOUNT OF
MOISTURE WILL MOVE FROM THE OHIO VALLEY SUN EVENING TO A POSITION
OFF THE COAST MON AFTERNOON. IT WILL BRING A 24 HR PERIOD OF MOSTLY
LIGHT SNOW ACROSS SRN PA/NE MD AND DEL DURING THE PERIOD. A COUPLE
PERIODS OF MODERATE SNOW COULD OCCUR...BUT SNOW TOTALS OF 1 TO 3
INCHES SRN PA/SRN NJ AND 2 TO 4 NE MD AND DEL WILL OCCUR. THE LOW
WILL NOT BE THAT STRONG...SO WINDS/BLOWING SNOW NOT EXPECTED TO BE
THAT MUCH OF AN ISSUE. TEMPS BELOW NORMAL WITH HIGHS 20 NORTH AND
LOW/MID 30S OVER THE DELMARVA AND SRN NJ. A BIT OF RAIN COULD MIX IN
WITH THE SNOW OVER SRN DEL ON MONDAY.

MON NIGHT THRU TUE...THE CLIPPER SYSTEM WILL BE OFFSHORE MON NIGHT
AND OTHER ENERGY AT THE BASE OF THE TROUGH WILL MEET IT CAUSING A
DEEP LOW TO DEVELOP OFF THE DELMARVA AND MOVE NORTHEAST. THIS SYSTEM
WILL DEEPEN RAPIDLY CREATING GUSTY WINDS AND A SHIELD OF HEAVY QPF.
THIS HEAVY QPF (SNOW) WILL FALL ACROSS THE DELMARVA AND SE NJ FOR A
TIME MON NIGHT BEFORE MOVING OFFSHORE. THE OPERATIONAL MODELS HAVE
SOME DEGREE OF UNCERTAINTY WITH THE SYSTEM...AND ANY TRACK FURTHER
WEST WOULD BRING EXCESSIVE SNOWS INTO THE NJ AREA TUE. WE HAVE NOT
GONE THIS ROUTE PRESENTLY...ALTHOUGH THE 12Z EC MODEL SEEMS TO
SUGGEST THIS. THE 12Z EC MODEL HAS BEEN DISCOUNTED BY WPC DUE TO
CONVECTIVE FEEDBACK ISSUES.  WE HAVE GONE ALONG WITH THE WWD AND
PAINTED SOME ACCUM SNOW ACROSS ERN NJ TUE. OUR TOTALS FOR THIS
PERIOD ARE LIKELY TO CHANGE OVER THE NEXT FEW FCST CYCLES...SO PAY
ATTENTION TO THE DETAILS IN FUTURE FCSTS.

TUE NIGHT THRU WED NIGHT... HIGH PRESSURE WILL AFFECT THE WEATHER
DURING THIS PERIOD WITH FAIR BUT COLD WEATHER EXPECTED. TEMPERATURES
WILL BE AVERAGING AROUND 10 TO 12 DEGREES BELOW NORMAL. HIGHS WED
MOSTLY IN THE LOW 20S UP NORTH AND MID TO UPPER 20S OVER THE SRN
2/3RDS OF THE AREA. COLD OVERNIGHT LOWS IN THE SINGLE DIGITS NORTH
AND TEENS SOUTH.

THU INTO FRI...MODELS ARE SHOWING ANOTHER CLIPPER TYPE SYSTEM
APPROACHING FROM THE WEST AFTER THE MID WEEK PERIOD. TEMPERATURES
WILL HAVE BEGUN TO MODERATE BY THE TIME THE PRECIP ARRIVES...SO SOME
RAIN/SNOW LINE ISSUES WILL OCCUR. MOSTLY USED CHC POPS FOR NOW.
TEMPS WILL STILL BE BELOW NORMAL...BUT NOT AS COLD AS WED. HIGHS IN
THE MID/UPPER 30S SOUTH AND LOW 30S NORTH.

&&

.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

TODAY...VFR. SOME MVFR CIGS POSSIBLE EARLY AT RDG/ABE BEFORE
LIFTING. STRATOCU DECK WILL REMAIN IN PLACE MOST OF THE DAY UNDER
WESTERLY WINDS WITH SOME GUSTS EXPECTED. SOME BACKING IN THE WINDS
IS EXPECTED LATER THIS EVENING AHEAD OF AN APPROACHING CLIPPER-LIKE
SYSTEM RIDING TOWARDS THE EAST, WELL SOUTH OF OUR REGION.

TONIGHT...MVFR/IFR IN AREAS OF SNOW. TIMING IS STILL A BIT SUSPECT
BUT LIGHT SNOW SHOULD OVERSPREAD FROM THE SOUTHWEST-NORTHEAST BY
LATE TONIGHT. MINIMAL RAIN/SNOW MIXING EXPECTED...MOSTLY WELL SOUTH
INTO SOUTHERN DELAWARE. EXPECT SOME LIGHT ACCUMULATIONS THROUGH
EARLY MONDAY MORNING...AROUND AN INCH PHL/ILG, MAYBE 2 INCHES
RDG.

OUTLOOK...
MONDAY AND MONDAY NIGHT...IFR/LIFR SOUTH AND MVFR NORTH WITH A
LOW PRESSURE SYSTEM CROSSING THE AREA. STEADY SNOW
ILG/PHL/PNE/MIV/ACY.

TUESDAY...MOSTLY VFR INLAND BUT IFR/MVFR AT KACY/KMIV WITH A STRONG
LOW PRESSURE SYSTEM MOVING UP THE COAST. STRONG NE/N WINDS.

TUESDAY NIGHT THROUGH WEDNESDAY...MOSTLY VFR.

&&

.MARINE...
WEST-NORTHWEST WINDS ARE EXPECTED THROUGH TONIGHT AND SUNDAY, AND
SOME GUSTS IN THE 25 TO 30 KNOT RANGE WILL CONTINUE THROUGH LATE
TONIGHT FOR DELAWARE BAY AND THROUGH AROUND MIDDAY SUNDAY FOR THE
COASTAL WATERS. AS A RESULT, A SMALL CRAFT ADVISORY CONTINUES FOR
DELAWARE BAY THROUGH 11Z SUNDAY, WITH THE SMALL CRAFT ADVISORY
EXTENDED UNTIL 18Z SUNDAY FOR THE COASTAL WATERS. IN ADDITION TO THE
WIND GUSTS THROUGH THIS PERIOD, SEAS WILL ALSO REMAIN ELEVATED,
ESPECIALLY FOR THE COASTAL WATERS, MAINLY IN THE 5 TO 8 FOOT RANGE,
BEFORE GRADUALLY DIMINISHING DURING THE DAYTIME SUNDAY.

OUTLOOK...
SUNDAY NIGHT...WINDS AND SEAS BUILDING. SCA CONDITIONS BY MON DAWN.

MONDAY AND MONDAY NIGHT...MOSTLY GALE CONDITIONS ON THE WATERS.

TUESDAY THROUGH THURSDAY...SCA CONDITIONS WITH FREEZING SPRAY EXPECTED.

&&

.TIDES/COASTAL FLOODING...
ANOTHER NORTHEASTER IS EXPECTED TO AFFECT THE COASTAL WATERS OF
DELAWARE AND NEW JERSEY FROM MONDAY NIGHT INTO TUESDAY. MINOR TIDAL
FLOODING MAY OCCUR AROUND THE TIMES OF HIGH TIDE.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...GALE WATCH FROM MONDAY MORNING THROUGH MONDAY AFTERNOON FOR
     ANZ430-431-450>455.
     SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
     ANZ450>455.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ430-431.

&&

$$
SYNOPSIS...GORSE/O`HARA
NEAR TERM...GORSE
SHORT TERM...KLINE
LONG TERM...O`HARA
AVIATION...HEAVENER/O`HARA
MARINE...KLINE/O`HARA
TIDES/COASTAL FLOODING...






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.