Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 270223
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1023 PM EDT THU MAR 26 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE EAST OF THE REGION LATE TONIGHT. LOW
PRESSURE WILL DEVELOP OFFSHORE FRI NIGHT...AND TRACK TOWARDS THE
MARITIMES SATURDAY. AN UPPER LEVEL DISTURBANCE MOVES ACROSS
SATURDAY AND MOVES EAST OF THE REGION SATURDAY NIGHT. HIGH
PRESSURE BUILDS IN THEREAFTER. FOR THE NEW WORK WEEK...A SERIES OF
CLIPPER LOWS WILL BE MOVING ACROSS.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE COLD FRONT WAS MOVING THROUGH THE REGION AND WAS THROUGH
WESTERN CONNECTICUT...NEW YORK CITY...AND TO COASTAL CENTRAL NEW
JERSEY AT 02Z. SHOWERS AND ISOLATED THUNDERSTORMS REMAIN ALONG THE
FRONTAL BOUNDARY WITH LOCALLY HEAVY RAINFALL AND WIND GUSTS UP TO
30 MPH. WIDESPREAD VISIBILITY AHEAD OF THE FRONT IMPROVED TO A
MILE OR MORE SO THE DENSE FOG ADVISORY WAS CANCELLED. LINE WAS
WEAKENING AS STORMS MOVED INTO MORE STABLE AIR THROUGH CONNECTICUT
AND EAST OF NEW YORK CITY.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
THE FRONT EXITS THE AREA BUT THE APPROACHING UPR JET COULD SUSTAIN
LGT RAIN AT LEAST INTO THE MRNG. FOCUS THEN TURNS TO DEVELOPING
LOW PRES OFFSHORE AS THE H5 SHTRWV APPROACHES. THE NAM HAD HINTED
AT THIS YESTERDAY...AND NOW THE GFS...ALTHOUGH THE LONE SOLN WITH
THE 12Z SUITE...HAS LATCHED ON. THIS WOULD BRING PCPN IN LATE FRI
AFTN/EVE...THEN SPREADING WWD FRI NGT. AT THE SAME TIME...THE PCPN
WOULD TRANSITION TO SNOW OVERNIGHT AS THE COLD UPR TROF MOVES IN.
WITH NLY COMPONENT FLOW...THIS CHANGEOVER WOULD OCCUR EVEN DOWN TO
THE COASTS. HAVE INCLUDED CHC POPS FOR THIS EVENT...HOWEVER THE
ECMWF AND NAM SOLNS WOULD LEAVE THE AREA WITH BENIGN WX.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
RELATIVELY ACTIVE WEATHER PATTERN WILL BE PRESENT FOR THE WEEKEND
THROUGH EARLY NEXT WEEK. THIS IS DIAGNOSED BY SHARPER AND LESS
WAVELENGTH OF TROUGHS AND CORRESPONDING RIDGES. BY MID TO LATE NEXT
WEEK...THERE IS A LONGER WAVELENGTH AND HENCE CLOSER TO A ZONAL TYPE
OF FLOW OCCURRING WHICH WILL BE LESS AMPLIFIED.

THE MAIN UPPER JET WILL BE SOUTH OF THE REGION FOR THE WEEKEND
BEFORE LIFTING BACK NORTH OVER THE AREA AND BECOMING MORE BROAD WITH
LESS WIND SPEED FOR LATER NEXT WEEK.

AT THE SURFACE...ONE FEATURE TO FOCUS ON IS A LOW DEVELOPING ALONG
AN OFFSHORE COLD FRONT SATURDAY. THE CENTER OF THE LOW DEPENDING
ON THE MODEL CHOSEN...IS APPROXIMATELY NEAR THE 40N AND 65W
COORDINATES. THE GFS IS MOST PROGRESSIVE WITH THIS LOW...MOVING IT
FASTER TO THE NORTHEAST INTO THE CANADIAN MARITIMES WHILE THE
ECMWF...NAM...AND CMC ARE REMARKABLY SLOWER.

ONCE THE LOW PUSHES FARTHER INTO THE CANADIAN MARITIMES SATURDAY
NIGHT...THEN HIGH PRESSURE...ORIGINATING FROM CENTRAL CANADA...WILL
GAIN MORE INFLUENCE AS IT BUILDS IN FROM THE WEST.  THE RIDGE OF
HIGH PRESSURE MOVES ACROSS SUNDAY AS THE CENTER OF HIGH PRESSURE
MOVES INTO THE SOUTHEAST.

A FAST MOVING CLIPPER LOW APPROACHES SUNDAY NIGHT...MOVING ACROSS
THE REGION MONDAY. THIS WILL BE FOLLOWED BY HIGH PRESSURE MONDAY
NIGHT INTO EARLY TUESDAY BEFORE ANOTHER QUICK MOVING CLIPPER LOW
MOVES IN TUESDAY NIGHT. HIGH PRESSURE RETURNS BEHIND IT LEADING
INTO EARLY THURSDAY BEFORE YET ANOTHER CLIPPER MOVES IN.

IN TERMS OF WEATHER...OVERALL COOLER THAN NORMAL TEMPERATURES WILL
CONTINUE. THIS WILL BE MOST PRONOUNCED THIS WEEKEND WITH FORECAST
HIGHS ONLY REACHING THE UPPER 30S TO LOWER 40S.

THERE WILL BE A FEW PERIODS TO WATCH FOR PRECIPITATION. THE HIGHEST
CHANCES ARE SATURDAY BEHIND THE COLD FRONT ASSOCIATED WITH
DEFORMATION TO THE WEST OF THE OFFSHORE DEEPENING LOW. QUITE THE
UNCERTAINTY HERE WITH NAM AND ECMWF SHOWING LITTLE TO NO
PRECIPITATION WHILE CMC AND GFS SHOW A LIGHT AMOUNT OF
PRECIPITATION...GENERALLY LESS THAN A QUARTER OF AN INCH. CURRENT
FORECAST TAKES INTO ACCOUNT AN AVERAGE OF ALL MODEL SOLUTIONS...WITH
GENERALLY LESS THAN 1 INCH OF SNOW AND WITH TEMPERATURES ABOVE
FREEZING...A LOT DEPENDS ON HOW MUCH DYNAMIC COOLING TAKES PLACE AS
WELL AS THE INTENSITY OF THE SNOW AS FAR AS HOW MUCH SNOW
ACCUMULATES ON THE GROUND.

OTHER CHANCES FOR PRECIP WILL BE MORE IN THE NATURE OF RAIN AND SNOW
SHOWERS LATE SUNDAY NIGHT INTO MONDAY AS WELL AS TUESDAY NIGHT INTO
WEDNESDAY. YET ANOTHER CHANCE OF SHOWERS FOR NEXT THURSDAY. THESE
ARE ALL ASSOCIATED WITH FAST MOVING CLIPPER LOWS.

&&

.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
A COLD FRONT WILL MOVE ACROSS THE TRI-STATE AREA TONIGHT. AN
APPROACHING UPPER LEVEL DISTURBANCE AND AN OFFSHORE LOW PRESSURE
SYSTEM WILL KEEP RAIN IN THE FORECAST THROUGH FRIDAY MORNING.

CONDS HAVE BEEN FLUCTUATION BETWEEN VFR AND IFR/LIFR EARLY THIS
EVE. AT 00Z...COLD FRONT WAS JUST ENTERING ORANGE COUNTY AND
WESTERN NJ. SHOWERS ASSOCIATED WITH THE FROPA MAY MIX UP THE CIGS
WITH VRB CONDS CONTINUING...ALTHOUGH EXPECT IFR/LIFR CONDS TO
MOSTLY PREVAIL UNTIL THE FRONT PASSES...THEN MVFR CONDS SHOULD
RETURN ALTHOUGH THE TIMING OF THIS IS UNCERTAIN...ESPECIALLY
EASTERN TERMINALS. OTHER UNCERTAINTY IS WHETHER CIGS ARE ABOVE OR
BELOW 2K FT.  KGON IS EXPECTED TO REMAIN IFR OR LOWER UNTIL FRI
MORNING. VFR CONDS RETURN W TO E FRI AFTN ALTHOUGH THIS MAY OCCUR
A FEW HOURS EARLIER THAN FORECAST.

COULD SEE GUSTS 25-30KT WITH THE FROPA THIS EVE. THEN GUSTY NW
WINDS EXPECTED AFT 04Z AT NYC TERMINALS.

   NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: COLD FROPA AROUND 03Z. MVFR CONDS EXPECTED
THROUGH FRI MORNING...THEN VFR.

KLGA FCSTER COMMENTS: COLD FROPA AROUND 03Z. MVFR CONDS EXPECTED
THROUGH FRI MORNING...THEN VFR.

KEWR FCSTER COMMENTS: COLD FROPA AROUND 02Z. MVFR CONDS EXPECTED
THROUGH FRI MORNING...THEN VFR.

KTEB FCSTER COMMENTS: COLD FROPA AROUND 02Z. MVFR CONDS EXPECTED
THROUGH FRI MORNING...THEN VFR.

KHPN FCSTER COMMENTS: COLD FROPA AROUND 03Z WITH LIFR CONDS
IMPROVING TO IFR...THEN MVFR AFTER 06Z. MVFR CONDS EXPECTED FRI
MORNING...THEN VFR.

KISP FCSTER COMMENTS: COLD FROPA AROUND 04Z WITH LIFR CONDS
IMPROVING TO IFR...THEN MVFR AFTER 06Z. MVFR CONDS EXPECTED FRI
MORNING...THEN VFR.

.OUTLOOK FOR 00Z FRIDAY THROUGH TUESDAY...
.FRI NIGHT-SAT...CHANCE OF MVFR CONDS WITH ANY RAIN OR SNOW
SHOWERS. N WINDS G15-20KT.
.SAT NIGHT-.SUNDAY NIGHT...VFR.
.MON...VFR. SW WINDS 15G20KT...BECOMING WNW AT NIGHT.
.TUE...VFR. NW WINDS 15-20G25-30KT...DIMINISHING AT NIGHT.

&&

.MARINE...
WITH THE WARM FRONT IN THE VICINITY OF THE FORECAST WATERS...AND
THE COLD FRONT APPROACHING EARLY THIS EVENING...EXPECT SHOWERS
AND ISOLATED THUNDERSTORMS TO REMAIN OVER THE WATERS. UPDATED
WEATHER THROUGH THIS EVENING. WIDESPREAD DENSE FOG WILL REMAIN
UNTIL THE COLD FRONTAL PASSAGE.

SCA REMAINS IN EFFECT FOR SRN WATERS WITH GUSTY SLY FLOW AND
BUILDING SEAS ON THE OCEAN. POTENTIAL OF OCNL SCA GUSTS ON THE
SOUND IF THE FRONT MAKES IT THRU. AREAS OF DENSE FOG ALSO LIKELY
TIL MIDNIGHT...THEN THE PASSAGE OF A CDFNT DISSIPATES IT LATE. SCA
COND REMAIN ON THE OCEAN FRI...AND WILL LIKELY NEED TO BE EXTENDED
AT LEAST THRU FRI NGT.

SCA POSSIBLE SATURDAY THROUGH EARLY SUNDAY AS WELL AS LATE SUNDAY
NIGHT THROUGH MONDAY NIGHT. THE NEXT CHANCE FOR SCA IS TUESDAY
NIGHT. THE SCA CHANCES WILL BE MAINLY ACROSS THE OCEAN AND EASTERN
WATERS. OTHERWISE...SUB SCA CONDITIONS ARE FORECAST FOR THE LONG
TERM FORECAST THIS WEEKEND AND NEXT WEEK OUTSIDE OF THE
AFOREMENTIONED TIME PERIODS.

&&

.HYDROLOGY...
UP TO A QUARTER INCH WITH LOCAL AMOUNTS OF A QUARTER TO ONE HALF
INCH OF PCPN IS EXPECTED INTO FRI MRNG. NO SIGNIFICANT WIDESPREAD
PRECIPITATION OTHERWISE EXPECTED ATTM.

CURRENTLY RIVERS AND STREAMS ARE EXPECTED TO REMAIN BELOW
BANK FULL...BUT THE MILD TEMPS AND INCREASED RIVER/STREAM FLOW
WILL INCREASE ICE BREAKUP AND MOVEMENT DURING THE NEXT FEW DAYS.
ISOLATED ICE JAMS ARE POSSIBLE...WHICH IF THEY OCCUR...COULD
RESULT IN LOCALIZED FLOODING. SINCE ICE JAM FLOODING IS
UNPREDICTABLE AND SUDDEN...INTERESTS ALONG ICE COVERED RIVERS
SHOULD MONITOR NWS FORECASTS FOR THE LATEST INFORMATION.

FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEB SITE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ330-335-
     340-345-350-353-355.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT FRIDAY FOR ANZ350-353-355.
     SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ345.

&&

$$
SYNOPSIS...JMC
NEAR TERM...JMC/MET
SHORT TERM...JMC
LONG TERM...JM
AVIATION...24
MARINE...JMC/JM/MET
HYDROLOGY...JMC/JM


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