Area Forecast Discussion
Issued by NWS Upton, NY

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FXUS61 KOKX 150844
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
444 AM EDT TUE APR 15 2014

.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE THROUGH THE AREA THIS
AFTERNOON INTO THIS EVENING. HIGH PRESSURE BUILDS IN FROM THE WEST
WEDNESDAY. HIGH PRESSURE MOVES NORTHEAST OF THE REGION TOWARDS THE
CANADIAN MARITIMES WEDNESDAY NIGHT THROUGH THURSDAY
NIGHT...WEAKENING DURING THE PROCESS. LOW PRESSURE ALONG A STALLED
FRONT TO THE SOUTH OF THE REGION APPROACHES FRIDAY AND PASSES EAST
OF THE REGION SATURDAY. HIGH PRESSURE RETURNS LATE SATURDAY NIGHT
INTO SUNDAY AND MOVES ACROSS THE REGION AND OFFSHORE EARLY NEXT
WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A STRONG COLD FRONT MOVES THROUGH THE AREA THIS AFTERNOON INTO THIS
EVENING. SCATTERED SHOWERS WERE ACROSS THE REGION THIS MORNING...AND
WILL BECOME MORE WIDESPREAD AS ATMOSPHERE BECOMES MORE UNSTABLE
DURING THE DAY LIGHT HOURS AND FORCING INCREASES. A STRONG LOW LEVEL
JET OF 60 TO 70 KT WILL ALSO AID IN THE LIFT ACROSS THE REGION LATE
THIS MORNING INTO THIS AFTERNOON. BEST INSTABILITY WILL BE ACROSS
NORTHEASTERN NEW JERSEY AND INTO THE LOWER HUDSON VALLEY WITH LOWER
INSTABILITY INTO NEW YORK CITY AND WESTERN LONG ISLAND WITH A STRONG
MARINE INFLUENCE. EXPECTING ISOLATED THUNDER WITH GUSTY WIND AS LOW
LEVELS WINDS ARE POTENTIALLY BROUGHT TO THE SURFACE...POTENTLY FOR
WIND GUSTS TO AROUND 50 MPH. ALSO...PRECIPITABLE WATER VALUES WILL
BE AROUND 1 1/2 INCH WHICH IS AROUND 2 1/2 TIMES NORMAL VALUE...SO
WILL MENTION POTENTIAL FOR HEAVIER RAINFALL. LOCALIZED URBAN AND LOW
LYING FLOODING POSSIBLE ACROSS NORTHEASTERN NEW JERSEY INTO NYC.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
COLD FRONT CROSSES THE REGION THIS EVENING INTO LATE TONIGHT WITH
THE PRECIPITATION ENDING. FORCING DIMINISHES QUICKLY WITH THE
PASSAGE OF THE FRONT WILL SOME LINGERING SHOWERS POST FRONTAL
POSSIBLE. MUCH COLDER AIR LAGS BEHIND THE FRONT THAT MUCH OF THE
PRECIPITATION IS ENDED BY THAT TIME. THERE IS JUST A SLIGHT CHANCE
OF SNOW SHOWERS JUST TO THE VICINITY OF THE NEW YORK CITY METRO AREA
LATE TONIGHT. AND NO ACCUMULATION IS EXPECTED.

MUCH COLDER AIR MOVES INTO THE AREA TONIGHT WITH LOWS 10 TO 15
DEGREES BELOW NORMAL. FREEZING OR NEAR FREEZING TEMPERATURES
EXPECTED ACROSS THE AREA TONIGHT. AND WITH THE GROWING SEASON
BEGINNING ACROSS PORTIONS OF THE LOWER HUDSON VALLEY AND
NORTHEASTERN NEW JERSEY HAVE ISSUED A FREEZING WARNING.

HIGH PRESSURE BUILDS IN FOR WEDNESDAY WITH A GUSTY NORTHWEST WIND IN
THE MORNING. TEMPERATURES WILL REMAIN WELL BELOW SEASONAL LEVELS
WITH HIGHS IN THE 40S...WHILE NORMAL HIGHS ARE IN THE UPPER 50S TO
LOWER 60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
MAIN UPPER LEVEL JET SOUTH OF THE REGION MID TO LATE THIS WEEK WITH
AS BROAD SOUTHWEST FLOW IN THE MID TO UPPER LEVELS. A SHORTWAVE IN
THE MID TO UPPER LEVEL WITH ACCOMPANYING JET STREAK WILL MOVE IN
FRIDAY NIGHT THROUGH SATURDAY AND EXIT EAST OF THE REGION SATURDAY
NIGHT. THE REGION WILL THEN BE ON A NORTHEAST SIDE OF A LARGE
WEAK...RATHER FLAT UPPER LEVEL RIDGE WITH ANOTHER SHORTWAVE MOVING
SOUTHEAST INTO THE AREA EARLY NEXT WEEK.

AT THE SURFACE...HIGH PRESSURE TRANSLATING NORTHEAST INTO THE
CANADIAN MARITIMES WILL ALLOW FOR A COOLER MARITIME TYPE OF AIRMASS
TO BE WITHIN THE REGION AS WE GET INTO A NORTHEAST FLOW REGIME. THIS
CONTINUES THROUGH FRIDAY BUT WITH WEAKENING WINDS...THE AIRMASS WILL
GRADUALLY MODERATE WITH A RESULTING SLOW INCREASE IN DAYTIME
TEMPERATURES EACH DAY.

IN TERMS OF WEATHER...DRY THROUGH THURSDAY NIGHT. THEREAFTER...A
TREND TOWARDS A MORE WET PATTERN EVIDENT STARTING FRIDAY WITH LOW
PRESSURE IN SOUTHEAST DEVELOPING AND APPROACHING ALONG A STALLED
FRONT. IN THE UPPER LEVELS A TROUGH WILL BE APPROACHING. CMC ONLY
MODEL SHOWING VERY LIGHT RAIN OR DRIZZLE ACROSS COASTAL SECTIONS
FRIDAY WITH GREATER MODEL AGREEMENT ON RAINFALL FRIDAY NIGHT INTO
SATURDAY.

THIS COMES WITH THE APPROACH OF THE TROUGH AND GREATER MOISTURE AND
WARM AIR ADVECTION WITH THE SOUTHWEST FLOW. RESIDUAL LIGHT NORTHEAST
FLOW AT THE SURFACE FURTHER INCREASES THE BOUNDARY LAYER MOISTURE.

THE TROUGH AXIS PUSHES EAST OF THE REGION SATURDAY NIGHT...ALLOWING
FOR A DRIER TREND TO WEATHER AS SHOWERS TAPER OFF AS MORE OF A
NORTHERLY FLOW WITH LESS EASTERLY COMPONENT SETTLES IN.

EARLY NEXT WEEK RETURN FLOW DEVELOPS AS HIGH PRES MOVES ACROSS AREA
AND EVENTUALLY OFFSHORE. AIRMASS WILL FURTHER MODERATE WITH WARMER
AND MORE MOIST AIRMASS MOVING IN.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
VARYING CONDITIONS FOR THE PERIOD AS A COLD FRONT APPROACHES AND
MOVES THROUGH THE REGION.

HIGHEST CONFIDENCE IS WITH STRONG SLY FLOW PERSISTING. WINDS
INCREASING GREATLY BY 10Z...WITH GUSTS UP TO 20-30 KTS FOR THE DAY.
TIMING OF FRONTAL PASSAGE SOMEWHERE 21-00Z...WITH WINDS SHIFTING
S-SW-NW DURING THIS TIME. WINDS WILL TAPER OFF SLIGHTLY WITH THE
FRONTAL PASSAGE...THEN INCREASE AGAIN AS THE WINDS SHIFT TO THE NW.

LLWS ISSUES PERSISTING THROUGH LATE AFTN...WITH GENERALLY 50-60
KTS BETWEEN 1-2KFT.

PCPN BEGINS TO PUSH IN BETWEEN 09-12Z...WITH THE HEAVIEST PCPN
LOOKING TO MOVE IN AFTER 15Z. COULD SEE A PERIOD OF +SHRA OR EVEN AN
ISO TSTM BETWEEN 15 AND 21Z...BUT CONFIDENCE OF COVERAGE TOO LOW TO
INCLUDE AT THIS TIME. COLD AIR RUSHING IN BEHIND THE FRONT COULD
ALSO RESULT IN LIGHT SNOW AT KSWF. THINKING THE END TIME OF THE PCPN
SHOULD OCCUR EVERYWHERE ELSE BEFORE THE COLDER AIR MOVES IN.

DEVELOPING FOG/STRATUS EARLY THIS MORNING WILL DROP CIGS/VIS TO
IFR OR LOWER. WILL SEE A BRIEF IMPROVEMENT WITH LIGHT PCPN MOVING
IN...THEN DROPPING DOWN AGAIN AFTER 15Z WITH THE HEAVIER RAIN.

...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)

KEWR FCSTER COMMENTS: GUSTS MAY BE MORE OCNL IN NATURE THROUGH 13Z.
IFR OR LOWER CONDITIONS MAY DELAY 1-2 HOURS.

THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.

KJFK FCSTER COMMENTS: CONDITIONS MAY IMPROVE 1-2 HOURS LATER THAN IN
TAF WITH PCPN.

KLGA FCSTER COMMENTS: LOW-MOD CONFIDENCE ON LIFR CONDITIONS WITH
PCPN.

KTEB FCSTER COMMENTS: LOW-MOD CONFIDENCE ON IFR CONDITIONS WITH
PCPN.

KHPN FCSTER COMMENTS: VIS MAY STAT REDUCED LESS THAN 1SM 10-15Z.

KISP FCSTER COMMENTS: LIFR CONDITIONS MAY PERSIST WITH PCPN AFTER
10Z.

.OUTLOOK FOR 09Z WEDNESDAY THROUGH SATURDAY...
.TUESDAY NIGHT...NW-N WIND G 35-40KT POSSIBLE.
.WEDNESDAY...VFR. N WIND G20-25KT POSSIBLE.
.WEDNESDAY NIGHT...VFR.
.THURSDAY...VFR. E WIND G 20-25KT POSSIBLE.
THURSDAY NIGHT-FRIDAY NIGHT...VFR.
.SATURDAY...LOW CHANCE OF -SHRA...WITH MVFR OR LOWER POSSIBLE IF
-SHRA OCCURS.

&&

.MARINE...
POTENTIAL FOR FOG ON THE WATERS INCREASES TONIGHT AND CONTINUES INTO
TUESDAY. A DENSE FOG ADVISORY HAS BEEN ISSUED WITH EXPECTATION OF
VSBY TO DROP BELOW 1 NM OVERNIGHT WITH CONTINUED MOIST FLOW.

SMALL CRAFT SEAS ON THE OCEAN CONTINUES TODAY WITH A STRONG
PERSISTENT SOUTHERLY FLOW ACROSS THE AREA. WITH AN INCREASE IN THE
SURFACE PRESSURE GRADIENT AND A STRENGTHENING LOW LEVEL JET WINDS
AND GUSTS ARE EXPECTED TO INCREASE TO SMALL CRAFT LEVELS THIS
MORNING. A LOW LEVEL INVERSION WILL KEEP HIGHER WINDS FROM MIXING TO
THE WATER SURFACE. SO HAVE POSTED A SMALL CRAFT ADVISORY FOR ALL THE
FORECAST WATERS TODAY. WITH CONVECTION MOVING INTO THE WATERS LATE
THIS MORNING INTO THIS AFTERNOON...PARTICULARLY THE WESTERN
WATERS...THERE IS THE POTENTIAL FOR BRIEF GALE FORCE GUSTS.

BETTER MIXING WILL OCCUR TONIGHT WITH THE PASSAGE OF A COLD FRONT AS
STRONG COLD ADVECTION SETS UP BEHIND THE FRONT. GALE FORCE GUSTS ARE
LIKELY AND UPGRADED THE WATCH TO A WARNING. GALE FORCE GUSTS MAY
CONTINUE INTO THE EARLY HOURS OF WEDNESDAY...MAINLY ACROSS THE
EASTERN ZONES...HOWEVER...DO NOT HAVE HIGH ENOUGH CONFIDENCE TO
EXTEND THE WARNING.

IN THE NORTHWEST FLOW SEAS ON THE OCEAN WILL BE SLOWLY SUBSIDING
THROUGH WEDNESDAY...FALLING BELOW 5 FT ACROSS THE WATERS EAST OF
MORICHES INLET BY LATE AFTERNOON. SO A SMALL CRAFT ADVISORY WILL
LIKELY BE NEEDED FOR SEAS WEDNESDAY IF THE GALE WARNING IS NOT
EXTENDED.

AFTER BRIEF LULL IN SCA CONDITIONS ACROSS OCEAN WED NIGHT...TOWARDS
DAYBREAK THU...RETURN OF SCA CONDITIONS FORECAST WITH EASTERLY FLOW
INCREASING. WINDS WILL TREND TO MOSTLY BELOW SCA BY LATE THU NIGHT
THROUGH REST OF MARINE FORECAST PERIOD. HOWEVER...SEAS WILL LIKELY
RETURN TO SCA LATE WED NIGHT ON THE OCEAN THROUGH FRIDAY BEFORE
DROPPING BELOW SCA FOR WEEKEND...ALTHOUGH BY THE END OF THE
WEEKEND...HIGHER SEAS COULD COME BACK IN ON THE OCEAN.

&&

.HYDROLOGY...
RAINFALL OF 1 1/2 TO 2 INCHES...MAINLY ALL LIQUID...EXPECTED FROM
EARLY THIS MORNING THROUGH LATE TONIGHT. THERE IS THE POTENTIAL
FOR LOCALLY HIGHER AMOUNTS OF 2 TO 3 INCHES.

MODERATE POTENTIAL EXISTS FOR MINOR FLOODING OF URBAN/POOR DRAINAGE
AREAS. ALSO LOW TO MODERATE POTENTIAL FOR FLASHY SMALL STREAMS
ACROSS NORTHEASTERN NEW JERSEY INTO THE LOWER HUDSON VALLEY TO REACH
MINOR FLOOD LEVELS WITH 1 HOUR FLASH FLOOD GUIDANCE AROUND 1 INCH.

NOTE...MINOR FLOODING CONTINUES ALONG THE CONNECTICUT RIVER.
ADDITIONAL HEAVY RAINFALL WILL LIKELY CAUSE WATER LEVELS TO CONTINUE
TO RISE THROUGH THE WEEK...WITH POTENTIAL FOR MODERATE FLOOD LEVELS
TO BE REACHED. MONITOR THE LATEST FLOOD WARNINGS FROM NWS TAUNTON MA.

AFTER TONIGHT NO SIGNIFICANT WIDESPREAD PRECIP EXPECTED.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...FREEZE WARNING FROM 2 AM TO 10 AM EDT WEDNESDAY FOR NYZ069-070.
NJ...FREEZE WARNING FROM 2 AM TO 10 AM EDT WEDNESDAY FOR NJZ004-006-
     103>108.
MARINE...DENSE FOG ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ330-335-
     338-340-345-350-353-355.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ330-
     335-338-340-345-350-353-355.
     GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
     ANZ330-335-338-340-345-350-353-355.

&&

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









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