Area Forecast Discussion
Issued by NWS Upton, NY

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 KOKX 240754
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
354 AM EDT THU JUL 24 2014

.SYNOPSIS...
A COLD FRONT MOVES SLOWLY EAST TODAY. HIGH PRESSURE BUILDS TONIGHT
AND FRIDAY. HIGH PRESSURE MOVES FARTHER OFFSHORE ON SATURDAY. A
FRONTAL SYSTEM APPROACHES SATURDAY NIGHT INTO SUNDAY...WITH AN
ASSOCIATED AREA OF LOW PRESSURE PASSING TO THE NORTHWEST ON
MONDAY. FOLLOWING THE COLD FRONT PASSAGE...HIGH PRESSURE BUILDS IN
TOWARDS MID-WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE COLD FRONT MOVES SLOWLY EAST TODAY AS UPPER TROUGH APPROACHES
FROM THE WEST.

DRIER AIR MOVES IN FROM THE NW...WITH WEAK COLD AIR ADVECTION NOTED
BEHIND THE FRONT AND WITH THE APPROACH OF THE TROUGH.

CANNOT RULE OUT ISOLATED SHOWERS...MAINLY EASTERN LOCALES PER 12KM
WRF...WRF-NMM...WRF-ARW...HRRR AND CANADIAN. DEVELOPMENT OF SHOWERS
REMAINS POSSIBLE DUE TO EXPECTED WEAK CAPE...AND VORTICITY
ADVECTION IN THE MID LEVELS. IN GENERAL THOUGH...DRY WEATHER IS EXPECTED
FOR MOST LOCATIONS.

ASSUMING MIXING UP TO ABOUT H8...HIGH TEMPS IN THE LOWER 80S SEEM
REASONABLE BASED ON H8 TEMPS SETTLING AROUND 12C PER NAM AND GFS.
MOS NUMBERS CLOSE AND ACCEPTED.

CANNOT RULE OUT LATE DAY SEA BREEZES IF WINDS REMAIN SUFFICIENTLY
WEAK.

A MODERATE RISK OF RIP CURRENTS EXISTS FOR EASTERN LONG ISLAND
BEACHES TODAY WITH RESIDUAL SOUTHERLY SWELLS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
UPPER TROUGH MOVES ACROSS THE AREA AND LIFTS TO THE NORTH THROUGH
THIS TIME FRAME. AT THE SFC...HIGH PRESSURE BUILDS FROM THE WEST.

ANY EVENING SHOWERS GIVE WAY TO DRY WEATHER WITH LOWER HUMIDITY.
A LIGHT NORTHERLY WIND TONIGHT WILL GIVE WAY TO ONSHORE FLOW
FRIDAY AS THE HIGH MOVES OVERHEAD.

MOS TEMPS ARE CLOSE...WITH 50S ACROSS THE INTERIOR...AND 60S NEAR
THE COAST TONIGHT...AND UPPER 70S TO LOWER 80S FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS HIGH PRESSURE SHIFTS FARTHER OFFSHORE ON SATURDAY...RETURN FLOW
WILL HELP INCREASE MOISTURE ACROSS THE TRI-STATE.
ADDITIONALLY...WEAK H5 SHORTWAVES PASSING NEAR/JUST NORTH OF THE
AREA IN ZONAL FLOW RESULT IN SLIGHT/LOW CHC POPS ACROSS THE AREA.

LATE SATURDAY NIGHT INTO SUNDAY MORNING...A WARM FRONT WILL LIFT
ACROSS THE AREA AS A STRONGER SHORTWAVE PROGRESSES TO THE EAST
ACROSS SOUTHERN ONTARIO/QUEBEC. AS A RESULT...CHANCES FOR SHOWERS
AND STORMS WILL BE ON THE INCREASE...AS SW FLOW ALOFT INCREASES OVER
THE FRONTAL SURFACE.

AS THE WARM FRONT LIFTS NORTH AND EAST OF THE REGION DURING THE
FIRST HALF OF SUNDAY...THERE MAY BE SOMEWHAT OF A LULL IN ACTIVITY
ACROSS THE AREA. HOWEVER...WITH SEVERAL SHORTWAVES EMBEDDED IN THE
FLOW ALOFT AND THE INCREASING MOISTURE PRESENT...TIMING OF MORE
WIDESPREAD ACTIVITY IS FAIRLY UNCERTAIN. 24/00Z GFS IS MORE
ROBUST/QUICKER THAN 24/00Z CMC/ECMWF WITH A WAVE APPROACHING FROM
THE WEST ON SUNDAY. BELIEVE IT IS A LITTLE TOO FAST...THEREFORE DID
NOT GO WITH LIKELY POPS EVERYWHERE UNTIL SUNDAY NIGHT. DURING THIS
TIME...THE CMC SOLUTION INDICATES THE POTENTIAL FOR WIDESPREAD HEAVY
RAIN...AS SOMEWHAT STRUNG-OUT CYCLOGENESIS TAKES PLACE ACROSS THE
AREA...AND A STRONG LLJ DEVELOPS ALONG AN AXIS OF HIGHER H5 THETA-E.
ECMWF APPEARS TO KEEP THE UPPER-LEVEL JET DYNAMICS A LITTLE FARTHER
NW/WEAKER...RESULTING IN HIGHER QPF BYPASSING THE AREA TO THE NW.
REGARDLESS...PRECIP APPEARS LIKELY BY SUNDAY NIGHT.

CHANCES FOR RAIN GRADUALLY DIMINISH MONDAY INTO MONDAY NIGHT AND
TUESDAY...AS THE ASSOCIATED SURFACE COLD FRONT MOVES THROUGH THE
AREA AND OFF TO THE EAST. NONETHELESS...WITH THE DEEP UPPER-LEVEL
TROUGH TAKING HOLD AND CYCLONIC FLOW ACROSS THE REGION...SOME
DIURNAL ACTIVITY IS POSSIBLE TUESDAY.

FOLLOWING THE FRONTAL PASSAGE...TEMPS LOOK TO BE A FEW DEGREES BELOW
NORMAL TUESDAY INTO WEDNESDAY.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
COLD FRONT HAS PUSHED EAST OF NYC TERMINALS AND WILL CONTINUE
EASTWARD THROUGH THE NIGHT...PUSHING E OF KGON BY MORNING. AN
UPPER TROUGH WILL PASS THROUGH TODAY...BRINGING THE CHC OF ISOLD
SHRA/TSTMS MAINLY E OF NYC.

SHRA/TSTMS HAVE CEASED FOR THE TIME BEING WITH VFR CONDS ACROSS
THE AREA. COULD BE PATCHY MVFR FOG WHERE WINDS LIGHTEN BELOW 5 KT
AND EVEN LOW CLOUDS FLOATING AROUND EAST OF KISP/KBDR OVERNIGHT.
MVFR CIGS CURRENTLY AT KSWF EXPECTED TO LIFT/SCT OUT BETWEEN 09Z
AND 12Z WITH THE INCREASING AND DRYING NLY FLOW. VFR CONDS THEN
EXPECTED ALL TERMINALS THROUGH 06Z FRI...EXCEPT IN ANY ISOLD
SHRA/TSTMS LATER TODAY WHERE THEY COULD BRIEFLY DROP OF MVFR.

MODERATE TO HIGH CONFIDENCE IN WIND FORECASTS. LOW LEVEL WINDS IN
THE MODEL GUIDANCE HAS TRENDED LOWER DURING THE DAY...THEREFORE
DO NOT THINK THERE WILL BE MUCH IN THE WAY OF GUSTS. IN LIGHT OF
THIS...THE POTENTIAL FOR SEABREEZE DEVELOPMENT IS POSSIBLE
ALTHOUGH HIGHEST CHC IS AT KGON/KBDR AND POSSIBLY KJFK LATE IN THE
DAY. DUE TO LACK OF CONFIDENCE AT KJFK...HAVE ONLY TEMPO`ED FOR
NOW. OTHERWISE...THERE IS SOME INDICATING THAT WIND DIRECTIONS MAY
BACK 30-40 DEGREES AT COASTAL TERMINALS AFT 18Z.

NYC TERMINALS: DIRECTIONS BECOME RIGHT OF 310 MAGNETIC BY 09Z AND ARE
FORECAST TO REMAIN RIGHT OF 310 THROUGH THE TAF PERIOD.

.OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY...
.THURSDAY NIGHT-SATURDAY...VFR.
.SATURDAY NIGHT-MONDAY...VFR WITH A CHANCE OF SHRA/TSTMS WITH MVFR
OR LOWER POSSIBLE.

&&

.MARINE...
A COLD FRONT SLOWLY MOVES EAST OF THE WATERS TODAY AND TONIGHT. HIGH
PRESSURE BUILDS IN FRIDAY. SUB SCA CONDITIONS ARE ANTICIPATED TODAY
THROUGH FRIDAY.

RELATIVELY TRANQUIL CONDITIONS LOOK TO EXIST ON THE OCEAN WATERS
THROUGH SATURDAY. WITH STRENGTHENING S/SW WINDS SATURDAY NIGHT
INTO SUNDAY...SEAS LOOK TO REACH SCA CRITERIA DURING THE SECOND
HALF OF THE WEEKEND INTO EARLY NEXT WEEK.

&&

.HYDROLOGY...
AREAS OF LOW PRESSURE PASSING NEAR THE AREA SUNDAY INTO MONDAY
HAVE THE POTENTIAL TO PRODUCE SHOWERS AND STORMS CAPABLE OF HEAVY
RAIN. SIGNIFICANT UNCERTAINTY STILL EXISTS WITH TIMING/AMOUNTS
THOUGH...SO WILL NOT OUTLOOK IN HWO AT THIS TIME.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...PICCA/PW
NEAR TERM...PW
SHORT TERM...PW
LONG TERM...PICCA
AVIATION...
MARINE...PICCA/PW
HYDROLOGY...PICCA/PW






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