National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KOKX 170059
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
859 PM EDT SUN JUN 16 2013

.SYNOPSIS...
A SERIES OF WEAK FRONTS WILL IMPACT THE AREA TONIGHT THROUGH MONDAY
NIGHT...WITH A COLD FRONT SLOWLY PUSHING THROUGH TUESDAY INTO TUESDAY
EVENING. THE COLD FRONT MOVES FARTHER OFFSHORE LATE TUESDAY NIGHT.
CANADIAN HIGH PRESSURE BUILDS IN WEDNESDAY...CENTERS OVER THE
REGION WEDNESDAY NIGHT AND THEN MOVES OFFSHORE ON THURSDAY.
OFFSHORE HIGH PRESSURE REMAINS INTO NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
COVERAGE OF ANY SHOWERS HAS BEEN MINIMAL OVER THE LAST FEW HOURS
AND EVEN A LINE OF SHOWERS THAT FORMED SOUTHEAST OF BINGHAMTON HAS
DECREASED WITH SOUTHEASTWARD MOVEMENT. SHOWERS ACROSS NORTHEAST
PA HAVE DEVELOPED WITHIN THE PAST HOUR...WITH SOME HIGHER
EMBEDDED HIGHER REFLECTIVITIES WITHIN THE SHOWERS.

HRRR HAS STRUGGLED OVER THE LAST SEVERAL RUNS SHOWING MODERATE
SHOWERS MOVING ACROSS THE LOCAL REGION BETWEEN 22-00Z...WHICH HAVE
NOT MATERIALIZED. BUT CONSIDERING LAPS CAPE VALUES HAVE BEEN
INCREASING SLIGHTLY TO A FEW HUNDRED J/KG WITH THIS INCREASING
INTO THE EARLY EVENING AS WELL AS A WEAK TROUGH MOVING
THROUGH...CANNOT RULE OUT A SHOWER OR THUNDERSTORM DEVELOPING THIS
EVENING. HOWEVER CONFIDENCE IS LOWERING ON THIS AND
CORRESPONDINGLY...POPS HAVE BEEN LOWERED FROM THE PREVIOUS
FORECAST. OUTSIDE OF THE NORTHERN PORTIONS OF THE LOWER HUDSON
VALLEY AND PERHAPS WESTERN PASSAIC NEW JERSEY WHERE THERE ARE POPS
OF 25 PERCENT OVER THE NEXT FEW HOURS...THE REST OF THE REGION IS
BELOW THIS AT A SLIGHT CHANCE. FOR MOST LOCATIONS...EXPECTING A
DRY FORECAST TONIGHT ESPECIALLY AFTER 3Z WHEN ANY CAPE GENERATED
SHOULD BE LOWERING AS TEMPS LOWER.

A COMBINATION OF MAV/NAM MOS WAS KEPT FOR MIN TEMPS...GENERALLY A
FEW DEGREES ABOVE NORMAL.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY/...
ANOTHER WEAK SURFACE TROUGH MOVES IN DURING MONDAY AFTERNOON.
PARTIAL SUNSHINE SHOULD ALLOW US TO DESTABILIZE...ESPECIALLY AWAY
FROM THE COAST. SO AFTER A DRY MORNING...EXPECTING SCATTERED
AFTERNOON AND EVENING SHOWERS AND TSTMS. THERE IS A SOMEWHAT BETTER
CHANCE FOR STRONG TO SEVERE TSTMS VERSUS THIS EVENING AS CAPE VALUES
WILL BE HIGHER. BUT IT IS STILL LOOKING LIKE AN OVERALL LOW CHANCE
FOR SEVERE WX.

MIXING PROFILES DO NOT CHANGE ALL THAT MUCH REGARDING MONDAY/S
HIGHS...BUT THINKING IS THAT WE HAVE A LITTLE MORE IN THE WAY OF
SUNSHINE OVERALL FOR IT TO BE A LITTLE WARMER IN GENERAL THAN IT
WAS TODAY. STILL WENT A LITTLE BELOW GUIDANCE...MORE SO NEAR THE
SOUTH-FACING COASTS.

A WEAK COLD FRONT SLOWLY DRIFTS EAST THROUGH THE FORECAST AREA
DURING TUESDAY. ONCE AGAIN...SCATTERED SHOWERS AND THUNDERSTORMS.
STRONG TO SEVERE WX CHANCES STILL LOW...BUT THE AIR MASS WILL BE A
LITTLE MORE MOIST VERSUS MONDAY AND THERE COULD BE THE PRESENCE OF
SYNOPTIC LIFT COURTESY OF AN UPPER JET STREAK. WENT SLIGHTLY BELOW A
GUIDANCE BLEND AGAIN FOR HIGHS DUE TO THE ANTICIPATED CLOUD COVER.

RISK OF RIP CURRENTS FOR MONDAY WILL BE LOW IN THE MORNING BUT
WILL BE MODERATE IN THE AFTERNOON AS FLOW BECOMES MORE SOUTHWEST
AND INCREASES TO 10-12 KT ALONG WITH A 11 SEC PERIOD 2 FT SWELL.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --
ALOFT...250MB JET STREAM WILL BE NEAR THE REGION WITH AN EXITING JET
STREAK OF 80-90 KT. RIGHT REAR QUAD OF THIS JET STREAK WILL ENHANCE
UPPER LEVEL DIVERGENCE AND PROMOTE LIFT. THE WILL HELP A PARENT LOW
IN THE CANADIAN MARITIMES DEEPEN SLIGHTLY AS WELL.
MEANWHILE...ANOTHER LOW WELL TO OUR SOUTH WILL BE MOVING OFF THE
CAROLINA COASTLINE. THE TROUGH IN MID LEVELS WILL BECOME LESS
AMPLIFIED TUESDAY NIGHT THROUGH WEDNESDAY. CANADIAN HIGH PRESSURE
WILL MAKE MORE EASTWARD PROGRESS INTO THE REGION WEDNESDAY INTO
WEDNESDAY NIGHT.

THE UPPER LEVEL JET LIFTS A LITTLE MORE TO THE NORTH OF THE REGION
WEDNESDAY NIGHT THROUGH NEXT WEEKEND WITH A FLAT ZONAL FLOW IN THE
MID LEVELS AS STEADY RIDGING WILL OCCUR. HIGH PRESSURE CENTERS OVER
THE REGION WEDNESDAY NIGHT AND BECOMES MORE ESTABLISHED OFFSHORE
THURSDAY AND INTO NEXT WEEKEND.

IN THE TIME FRAME OF TUESDAY NIGHT...EXPECTING THE COLD FRONT TO BE
LOCATED SOUTHEAST OF LONG ISLAND WITH SHOWER CHANCES LOWERING AS A
DRY NORTHERLY FLOW MOVES IN PLACE. THIS WILL BE ON THE RIGHT SIDE
OF A HIGH PRESSURE AREA STARTING TO BUILD IN FROM THE GREAT LAKES.

AN INTERESTING NOTE HERE IS THAT THE MODELS ARE HAVING SOME
DIFFICULTY IN FORECASTING SHOWERS TUESDAY NIGHT...WITH
INCONSISTENCIES ON THE 24-48 HR TRENDS WITH GFS ENSEMBLE AND ECMWF.
ECMWF HAS TRENDED RELATIVELY MORE WET WHILE GFS ENSEMBLE HAS TRENDED
RELATIVELY MORE DRY. TWO DAYS AGO THESE MODELS WERE REVERSED IN
THEIR PRECIP DEPICTIONS. SO...ACCOUNTING FOR THIS...DID NOT CHANGE
MUCH FROM PREVIOUS FORECAST PACKAGE KEEPING CHANCES EARLY AND THEN
GRADUALLY LOWERING TO SLIGHT CHANCE FROM NORTHWEST TO SOUTHEAST.

A COOLER AIR MASS WILL BE USHERED INTO THE REGION ON THIS NORTHERLY
FLOW FOR WEDNESDAY. THE VERTICAL PROFILE SHOWS A BACKING OF WIND TO
MORE OF A WESTERLY FLOW IN THE 800-500 MB LAYER...CONVEYING COLD AIR
ADVECTION. 850 MB TEMPS WILL BE 8-10 DEGREES C TAKING A MODEL
CONSENSUS WITH ECMWF NOTABLY 1-2 DEGREES COOLER. HIGHS ARE FORECAST
TO BE MAINLY IN THE LOW TO MID 70S...WHICH WILL BE A FEW DEGREES
COOLER THAN NORMAL.

HIGH PRESSURE CENTERING OVERHEAD WEDNESDAY NIGHT INTO THURSDAY
MORNING WITH LIGHT WINDS AND SUBSIDENCE WILL PROVIDE MOSTLY CLEAR
CONDITIONS. THIS WILL RESULT IN GOOD RADIATIONAL COOLING CONDITIONS.
LOWS WEDNESDAY NIGHT ARE FORECAST TO BE WELL INTO THE 50S...MID TO
UPPER 50S FOR COAST AND URBAN LOCATIONS WHILE INTERIOR AND RURAL
SECTIONS WILL BE IN THE UPPER 40S TO LOWER 50S. AGAIN...THIS WILL BE
AT LEAST A FEW DEGREES BELOW NORMAL.

HIGH PRESSURE WILL TRANSLATE OFFSHORE ON THURSDAY WITH A LITTLE
REBOUND IN TEMPERATURES AS THE AIR MASS MODERATES TO A MORE
SEASONABLE ONE. RIDGING ALOFT WILL HELP IN THIS EFFORT AS WELL WITH
THE SUBSIDENCE FACTOR STILL STRONG ENOUGH TO PRECLUDE ANY DIURNAL
INDUCED SHOWER OR THUNDERSTORM. THEREFORE EXPECTING ANOTHER DRY DAY.
MAX TEMPS ARE FORECAST TO BE MORE IN THE UPPER 70S TO NEAR 80 FOR
THE AREA...CLOSER TO NORMAL BUT STILL SLIGHTLY BELOW NORMAL FOR A
FEW SPOTS.

EVEN WITH LIGHT WINDS THURSDAY NIGHT AS HIGH PRESSURE BUILDS
OFFSHORE...RIDGING ALOFT WILL STILL BE IN A POSITIVE TREND SO
ACCORDINGLY TEMPS WILL BE NOT BE AS COOL AS THE PREVIOUS NIGHT WITH
LOWS SEVERAL DEGREES WARMER.

THE MAIN THEME FOR THE REST OF THE LONG TERM FOR FRIDAY INTO NEXT
WEEKEND WILL BE CLOSER TO A TYPICAL SUMMERTIME PATTERN WITH HIGH
PRESSURE STAYING OFFSHORE AND UPPER LEVEL RIDGING. THE 500MB
HEIGHTS STAY ABOVE 582 DM WITH THE GFS SHOWING SLIGHTLY LARGER
HEIGHTS THAN THE ECMWF. 850MB TEMPS GENERALLY 12-14 DEGREES C.
SUBSIDENCE WILL BE GRADUALLY LOWERING AS THE DIURNAL INSTABILITY
RISES ENOUGH TO GIVE A POSSIBLE SHOWER OR THUNDERSTORM NORTH AND
WEST OF THE CITY FRIDAY AND SATURDAY WITH OVERALL A GREATER CHANCE
NEXT SUNDAY AHEAD OF THE NEXT TROUGH AND COLD FRONT. HOWEVER...THIS
COULD CHANGE ON THE ORDER OF 6HRS OR SO WITH SUBSEQUENT FORECASTS.
MAX TEMPERATURES WILL BE PRETTY CLOSE TO NORMAL VALUES.
-- End Changed Discussion --

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
FOR THE NYC METRO...W WINDS AROUND 15G25KT ATTM SHOULD DIMINISH
SLIGHTLY EARLY THIS EVENING...THEN MAY VEER A LITTLE MORE W-NW AND
DIMINISH TO UNDER 10 KT LATE THIS EVENING AS A SFC TROUGH PASSES
THROUGH. ONE LONE SHOWER CROSSING INTO NW NJ IS HEADED TOWARD
EITHER KTEB/KEWR AND WOULD ARRIVE AT 03Z IF IT EVEN
SURVIVES...IMPACTS SHOULD BE VERY MINIMAL.

OUTSIDE THE NYC METRO AREA...MVFR VSBY OCCURRING ATTM AT KGON MAY
PERSIST FOR MOST OF TONIGHT. OTHER OUTLYING TERMINALS MAY APPROACH
MVFR CONDS WITH SOME HAZE LATE TONIGHT INTO EARLY MON MORNING.

COASTAL SEA BREEZES LIKELY ON MON. AN AFTERNOON SHOWER OR TSTM
POSSIBLE INLAND...IMPACTING MAINLY KSWF.

.OUTLOOK FOR 00Z TUE THROUGH FRI...
.MON NIGHT-TUE...SCT SHOWERS AND ISOLD-SCT TSTMS COULD BRING MVFR
OR LOWER CONDITIONS.
.WED-FRI...VFR.
-- End Changed Discussion --

&&

.MARINE...
-- Changed Discussion --
SMALL CRAFT ADVISORY FOR THE OCEAN WATERS WILL REMAIN POSTED THROUGH
TONIGHT. HAVING DOUBTS THAT THE WESTERNMOST WATERS REACHES 5 FT
SEAS...HOWEVER THERE IS STILL A CHANCE THAT 25 KT GUSTS OCCUR INTO
THIS EVENING THERE...ESPECIALLY NEAR SHORE. NOT ENOUGH CONFIDENCE TO
CANCEL THE SCA ALTOGETHER. ACROSS ALL OCEAN WATERS...THIS SEEMS TO
BE A MARGINAL EVENT. SUB-SCA CONDITIONS THEN PREVAIL MONDAY THROUGH
TUESDAY WITH W TO SW WINDS AT AROUND 10 KT OR LESS.

A COLD FRONT MOVES THROUGH LATE TUESDAY...AND THEN FARTHER
OFFSHORE TUESDAY NIGHT WITH HIGH PRESSURE GRADUALLY BUILDING IN
FOR MIDWEEK. THIS THEN MOVES OFFSHORE FOR LATE IN THE WEEK. THE
PRESSURE GRADIENT WILL BE WEAK ENOUGH FOR CONDITIONS TO STAY BELOW
SMALL CRAFT ADVISORY CRITERION TUESDAY NIGHT THROUGH FRIDAY.
-- End Changed Discussion --

&&

.HYDROLOGY...
THE PROBABILITY FOR WIDESPREAD SIGNIFICANT RAINFALL IS LOW
THROUGH THIS WEEK. WITH RECENT HEAVY RAINFALL...ANY ORGANIZED
STRONG CONVECTION THROUGH TUESDAY WOULD PRESENT A LOCALIZED
THREAT FOR URBAN...POOR DRAINAGE AND SMALL STREAM FLASH FLOODING.

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
WEBSITE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ350-353-355.

&&

$$
SYNOPSIS...JC/JM
NEAR TERM...JC/JM
SHORT TERM...JC
LONG TERM...JC
AVIATION...GOODMAN
MARINE...JC/JM
HYDROLOGY...JC/JM