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Area Forecast Discussion
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000
FXUS61 KOKX 040930
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
430 AM EST WED MAR 4 2015

.SYNOPSIS...
DEEPENING LOW PRESSURE TRACKS ACROSS EASTERN CANADA TODAY WITH A
COLD FRONTAL BOUNDARY APPROACHING AS A WAVE OF LOW PRESSURE
DEVELOPS ALONG IT SOUTHWEST OF THE REGION. THE COLD FRONT SLIDES TO
THE SOUTHEAST TONIGHT...WITH WAVES OF LOW PRESSURE TRACKING ALONG
IT INTO THURSDAY. CANADIAN HIGH PRESSURE THEN BUILDS IN THROUGH
THURSDAY NIGHT...THEN SLIDES TO OUR SOUTH THROUGH FRIDAY NIGHT. A
SERIES OF WEAK COLD FRONTS CROSS THE REGION THIS WEEKEND INTO
EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WSW FLOW REMAINS ACROSS THE REGION THROUGH THE DAY TODAY. PRETTY
MUCH A STEADY STATE ENVIRONMENT WITH TEMPS ONLY RISING A FEW
DEGREES AND INTERMITTENT LIGHT RAIN.

THE UPPER LEVEL JET STREAK OF AROUND 200 KT WILL BE APPROACHING
THROUGH THE DAY. TEMPS REMAIN GENERALLY IN THE MID TO UPPER 30S TO
KEEP PRECIPITATION IN THE FORM OF PLAIN RAIN. THE INTENSITY WILL
BE RATHER LIGHT DUE TO THE AREA NOT BEING IN A FAVORABLE REGION OF
LIFT RELATIVE TO THE JET STREAK PLACEMENT BUT INCREASED DIVERGENCE
ALOFT SHOULD ALLOW FOR RAIN FIELD TO EXPAND.

TEMPERATURES USED WERE A COMBINATION OF GMOS...NAM12 AND GFS40.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
MODELS IN GOOD AGREEMENT WITH NORTHERN STREAM ENERGY DIGGING DOWN 
THE FRONT RANGE OF THE ROCKIES INTO NORTHERN PLAINS/UPPER GREAT 
LAKES TODAY...INTERACTING WITH A SW US LOW...AND THEN GRADUALLY 
LIFTING ACROSS THE US TO EAST COAST BY THURSDAY NIGHT. 

HAVE STAYED CLOSE TO ENSEMBLE MEANS...WITH A REINFORCING COLD FRONT 
MOVING SOUTH OF THE REGION THIS EVE WITH FALLING TEMPS TONIGHT. A 
SERIES OF WAVES WILL DEVELOP ALONG A STATIONARY FRONT TO THE SOUTH 
...TRACKING NE THROUGH THE MID ATLANTIC...AHEAD OF APPROACHING UPPER 
TROUGH AXIS AND AS THE REGION FALLS UNDER FAVORABLE ENTRANCE REGION 
OF A 175-200KT UPPER JET. 

BIGGEST UNCERTAINTY EXISTS IN QPF...WITH MODELS WOBBLING BACK AND 
FORTH FROM RUN TO RUN ON NORTHERN EXTENT OF HEAVIER QPF AXIS. 
RELYING ON A ENSEMBLE APPROACH TO QPF...WITH 1/4 TO 3/4 INCH OF QPF 
ACROSS THE REGION AS THE SYNOPTIC SETUP TAPS INTO A MOIST SW FLOW 
ALL THE WAY FROM THE SUBTROPICAL PAC. ENSEMBLE INDICATING HIGHEST 
PROB OF .5 INCHES OR GREATER AFTER TRANSITION FOR SOUTHERN PORTIONS 
OF NYC/NJ METRO AND LI.  

MODELS IN GENERAL AGREEMENT WITH THERMAL PROFILES COOLING THROUGH 
THE OVERNIGHT...WITH A CHANGEOVER OF PRECIP FROM RAIN IN THE EARLY 
EVE TO WINTRY MIX THEN SNOW FROM NW TO SE. ALL AREAS APPEAR TO BE 
MAINLY SNOW BY 06Z. MODEST FRONTOGENETIC FORCING APPEARS TO BE ACROSS 
SOUTHERN ZONES...WITH POTETNIAL FOR SNOW TO BE HEAVY AT TIMES LATE 
TONIGHT THROUGH THU MORNING THERE...COUPLED WITH STRONG JET 
DYNAMICS. SNOW SHOULD GRADUALLY TAPER OFF IN INTENSITY AND COVERAGE 
FROM NW TO SE THURSDAY AFTERNOON AS SHORTWAVE TROUGH APPROACHES AND 
OFFSHORE STATIONARY FRONT SLIDES WELL OFFSHORE. 

HIGHEST CONFIDENCE IN 6+ INCH AMOUNTS IS FOR LI AND SOUTHERN 
PORTIONS OF NYC/NJ METRO. WILL UPGRADE TO WARNING IN THIS AREA AFTER 
COLLAB WITH PHI AND BOX. POTENTIAL FOR 3 TO 6 INCHES FOR COASTAL 
SOUTHERN CT...THE REST OF NE NJ...AND SOUTHERN PORTIONS OF LOWER 
HUDSON VALLEY. WILL LEAVE WATCH IN THESE AREAS WITH POTENTIAL FOR 6" 
BUT HIGHER LIKELIHOOD OF ADVISORY LEVEL. WITH A SHARP GRADIENT IN 
PRECIP ACROSS AREAS FAR N&W OF NYC...BETWEEN 1 TO 4 INCHES... 
NOT ENOUGH CONFIDENCE FOR AN ADVISORY AT THIS TIME.  
 
DRYING CONDITIONS THURSDAY NIGHT...WITH TEMPS DROPPING INTO THE 
SINGLE DIGITS...LOWER TEENS NYC METRO...ON GUSTY NW WINDS. 
WINDCHILLS LIKELY DROPPING TO AROUND ZERO TO 5 BELOW ZERO FOR MUCH 
OF THE REGION BY FRIDAY MORNING.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THEREAFTER...MEAN TROUGHING CONTINUES INTO EARLY NEXT WEEK. 
UNSEASONABLY COLD CONDS (ABOUT 20 DEGREES BELOW SEASONABLE) CONTINUE 
THU NIGHT INTO FRI NIGHT AS CANADIAN HIGH PRESSURE BUILDS INTO THE 
REGION. 

THEN A SERIES OF WEAK SHORTWAVE/COLD FRONTS MOVE THROUGH THE 
REGION THIS WEEKEND INTO EARLY NEXT WEEK...WITH TEMPS MODERATING BUT 
STILL REMAINING SEVERAL DEGREES BELOW SEASONABLE. SOME LIGHT RA/SN 
SHOWER ACTIVITY POSSIBLE WITH ANY OF THESE DISTURBANCES.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
LOW PRESSURE TRACKS ACROSS EASTERN CANADA TODAY...WITH ITS TRAILING 
COLD FRONT CROSSING THE AREA LATE TONIGHT INTO THURSDAY MORNING.

PCPN HAS ENDED FOR THE MOMENT AT ALL TERMINALS EXCEPT KGON...WHICH 
WILL FOLLOW SUIT OVER THE NEXT 1-2 HOURS AS WELL. HI RES MODELS ARE 
ALL OVER THE PLACE WITH TIMING PCPN TODAY...BUT EXPECTING AT LEAST 
2-3 HOURS OF DRY WEATHER. WATCHING NEXT AREA OVER CENTRAL 
PA...ALTHOUGH THE LEADING EDGE OF THIS HAS BEEN DRYING OUT AS IT 
ADVANCES EWD. THIS AREA IS CURRENTLY TIMED TO REACH WESTERN 
TERMINALS AROUND 10-11Z...BUT WILL NEED TO WATCH RADAR TRENDS TO SEE 
IF THIS WILL MATERIALIZE. ALL TERMINALS ARE NOW ABOVE THE FREEZING 
MARK...SO EXPECT PLAIN RAIN EVERYWHERE. 

ON AND OFF LIGHT RAIN IS THEN EXPECTED THROUGH THE DAY.

IFR SHOULD PREVAIL THROUGH THE MORNING...ALTHOUGH CONDITIONS MAY 
BOUNCE AROUND TO LIFR AND MVFR AT TIMES. IFR OR MVFR LIKELY THROUGH 
THE REST OF THE DAY...ALTHOUGH STRATUS MAY SCATTER...ESPECIALLY 
ACROSS THE INTERIOR. IF THAT DOES OCCUR...VFR CONDITIONS ARE 
POSSIBLE FOR A TIME.

SW WINDS 10 KTS OR LESS SHIFT TO THE SW-W. LLWS THROUGH 11Z OR SO. 

   ..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: EXACT TIMING OF RAIN THROUGH THE DAY IS 
UNCERTAIN. FLIGHT CATEGORY MAY VARY BETWEEN IFR AND MVFR THIS 
MORNING...AND MVFR AND VFR THIS AFTN. 

KLGA FCSTER COMMENTS: EXACT TIMING OF RAIN THROUGH THE DAY IS 
UNCERTAIN. FLIGHT CATEGORY MAY VARY BETWEEN IFR AND MVFR THIS 
MORNING...AND MVFR AND VFR THIS AFTN. 

KEWR FCSTER COMMENTS: EXACT TIMING OF RAIN THROUGH THE DAY IS 
UNCERTAIN. FLIGHT CATEGORY MAY VARY BETWEEN IFR AND MVFR THIS 
MORNING...AND MVFR AND VFR THIS AFTN. 

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS MODERATE...WHICH 
IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD.

KTEB FCSTER COMMENTS: EXACT TIMING OF RAIN THROUGH THE DAY IS 
UNCERTAIN. FLIGHT CATEGORY MAY VARY BETWEEN IFR AND MVFR THIS 
MORNING...AND MVFR AND VFR THIS AFTN. 

KHPN FCSTER COMMENTS: EXACT TIMING OF RAIN THROUGH THE DAY IS 
UNCERTAIN. FLIGHT CATEGORY MAY VARY BETWEEN IFR AND MVFR THIS 
MORNING...AND MVFR AND VFR THIS AFTN. 

KISP FCSTER COMMENTS: EXACT TIMING OF RAIN THROUGH THE DAY IS 
UNCERTAIN. FLIGHT CATEGORY MAY VARY BETWEEN IFR AND MVFR THIS 
MORNING...AND MVFR AND VFR THIS AFTN. 

.OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY...
.TONIGHT-THURSDAY...BECOMING IFR WITH A TRANSITION BACK TO SNOW 
AROUND MIDNIGHT. CHC N GUSTS TO 20 KT ON THURSDAY.
.THURSDAY NIGHT-FRIDAY...IMPROVING TO VFR THURS NIGHT. NW GUSTS 
15-20KT POSSIBLE THURSDAY NIGHT.
.SAT/SUN...VFR.

&&

.MARINE...
SCA CONDITIONS ARE EXPECTED TO CONTINUE ACROSS THE OCEAN WITH
OTHER WATERS REMAINING BELOW SCA. THE SCA EVENT WILL BE MORE OF A
MARGINAL ONE BUT ANY RAINFALL WILL BE HELP TRANSPORT MOMENTUM
DOWN AND GIVE SOME HIGHER GUSTS THAT WOULD REACH SCA THRESHOLDS.
WATER TEMPS ARE A FEW DEGREES WARMER ON THE OCEAN RELATIVE TO
OTHER WATERS SO IT WILL BE RELATIVELY EASIER FOR HIGHER GUSTS TO
BE ACHIEVED ON THE OCEAN.

SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY ON THE COASTAL OCEAN 
WATERS INTO THURSDAY MORNING AS A SERIES OF LOW PRESSURE WAVES 
TRACKS TO THE SOUTH OF THE WATERS. SOME UNCERTAINTY IF SCA CONDS 
CONTINUE INTO THU AFTERNOON...WITH HIGHER CONFIDENCE OF 
RE-OCCURRENCE THU NIGHT. SO FOR NOW HAVE ONLY RUN SCA UNTIL THU 
MORNING. 

SUB SCA CONDS RETURN FRI AS HIGH PRESSURE BUILDS OVER THE WATERS.

A SERIES OF WEAK COLD FRONTS WILL MOVE THROUGH THE WATERS THIS 
WEEKEND INTO EARLY NEXT WEEK...ONE SATURDAY NIGHT INTO SUNDAY 
MORNING AND ANOTHER MONDAY NIGHT. WINDS APPROACH SCA CRITERIA 
SATURDAY INTO SATURDAY NIGHT AND THEN AGAIN MONDAY NIGHT INTO 
TUESDAY ON THE OCEAN WATERS...BUT AS OF RIGHT NOW...THEY SHOULD 
REMAIN BELOW. WAVES REMAIN BELOW SCA CRITERIA THROUGH THE PERIOD.


&&

.HYDROLOGY...
AROUND A QUARTER OF AN INCH OR LESS IS EXPECTED WITH THE REMAINING
RAINFALL TODAY. LOW POTENTIAL FOR FLOODING ALTHOUGH SOME PONDING
OF WATER IS EXPECTED WITH STEADY MODERATE RAIN THAT FALLS DUE TO
EXCESS RUNOFF FROM MELTING SNOWPACK.

1/4 TO 3/4 INCH LIQUID EQUIVALENT PRECIPITATION IS LIKELY WEDNESDAY 
NIGHT INTO THURSDAY. MOST OF THIS WILL BE FROZEN...SO HYDROLOGIC 
IMPACTS ARE NOT EXPECTED.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING 
     FOR CTZ008>012.
NY...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST 
     THURSDAY FOR NYZ074-075-078>081-176>179.
     WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING 
     FOR NYZ071>073.
NJ...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST 
     THURSDAY FOR NJZ107-108.
     WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING 
     FOR NJZ002-004-006-103>106.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR ANZ350-353-
     355.

&&

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






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