Area Forecast Discussion
Issued by NWS Upton, NY

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349 FXUS61 KOKX 270239 AFDOKX Area Forecast Discussion National Weather Service New York NY 1039 PM EDT SUN JUN 26 2016 .SYNOPSIS... High pressure remains across the region into Monday and drifts east late Monday into Monday night as a slow moving cold front approaches. The cold front approaches Tuesday and moves across early Wednesday. Afterwards, it will linger south of Long Island during the day Wednesday before moving farther offshore Wednesday night. Weak high pressure returns Thursday through Friday. Another cold front approaches late Friday moving across Saturday and moving southeast of the region by next Sunday. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Surface high pressure remain centered east of Long Island tonight. Aloft a longwave trough moving through south central Canada reaches southeastern Canada by 12z Monday. The upper ridge over the area weakens late tonight as a closed low over the western Atlantic drifts westward and gets picked up by the Canadian trough. The airmass in place the last couple of days remains tonight with a slight increase in low level moisture on a southerly flow. As such...will have patchy fog/stratus potential across the far eastern coastal zones. && .SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
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The longwave upper trough continues to move slowly into eastern Canada with a shortwave rotating into the trough, extending into the Great Lakes region by late Monday night. The upper low over the western Atlantic get fully integrated into the upper trough during Monday. Meanwhile, a weak cold front will be approaching. The warm and humid airmass remains in place ahead of the cold front. There will be weak lift and instability by Monday afternoon with better instability by Monday evening inland. Will have slight chance pops by Monday afternoon across the western zones with only showers. This may still be too quick. Pops increase Monday night, still at chance, and progress slowly east through Monday night. Will have isolated thunder during the evening with the best instability. There is a borderline low to moderate risk for the development of rip currents at Atlantic ocean beaches Monday. If incoming swell energy falls to around 1 ft as depicted by development risk would be low...but some uncertainty on how quickly that will occur. With that said...15-20 kt afternoon coastal jet development should have rip risk increasing to moderate across NYC and Western LI beaches in the late afternoon/eve with increased wind waves.
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&& .LONG TERM /TUESDAY THROUGH SUNDAY/... The shortwave currently in the vicinity of Montana will be approaching the Northeast by early Tuesday. This will be associated with a deepening trough and this gradually moves in through Tuesday evening. Then the trough axis will be moving across on Wednesday. After that, there will still be a lingering upper level trough in the Northeast but less amplified. The associated jet max will be moving east of the region by Wednesday night with the next jet streak not moving in until Friday night into next weekend. At the surface, there will be an approaching cold front Tuesday and this front will move across early Wednesday. With low pressure developing along it, it may linger nearby just south of Long Island during the day Wednesday. The front will then move farther offshore Wednesday night with weak high pressure returning for Thursday through Friday. Another cold front approaches late Friday into Saturday and will eventually move offshore for next Sunday. In terms of weather, there will be two periods where rainfall will become more probable, Tuesday through Wednesday and Friday afternoon through Saturday night. Each of these periods will have chances of showers and thunderstorms as there will be low level instability and an upper level jet streak moving across. The relatively higher chances are with the Tuesday and Tuesday Night timeframe. In terms of temperatures, most daytime highs Tuesday and Wednesday will be in the upper 70s to lower 80s and then Thursday through next weekend will be mainly in the low to mid 80s. Lows forecast are pretty consistent during the long term period with values mainly ranging from the upper 50s to upper 60s. && .AVIATION /03Z MONDAY THROUGH FRIDAY/... High pressure remains just to the east of the region...with a frontal system approaching Mon Night. VFR...except for potential radiation/advection fog/stratus late tonight at KGON with light onshore flow under mostly clear skies. A few mvfr/ifr cigs possible at coastal terminals late tonight...gradually lifting above 3 kft through Mon morning. Low prob of a shower at KSWF late Mon. Light s/ssw tonight...increasing Mon Morning. S/SE seabreeze development expected at all but KSWF Mon afternoon. At KJFK/KLGA moderate potential for S winds 15-20 with gusts to 25 kt in late afternoon/early eve with coastal jet development...elsewhere generally 10 to 15 kt with gusts to 20 kt. .OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY... .Monday Night into Tuesday morning...S winds G20KT along the coast in the early evening. MVFR or lower conditions possible, with showers mainly from NYC metro north/west, and low clouds/patchy fog along the coast especially KGON/KISP. .Tuesday afternoon and night...MVFR or IFR conditions likely in showers and tstms. Stratus and fog possible at night, with IFR or lower conditions likely at coastal terminals. .Wednesday morning...IFR or lower conditions still possible via morning fog/low clouds and any stray showers. .Wednesday afternoon through Thursday...VFR. .Friday...MVFR or lower conditions with showers/tstms possible in the late afternoon from NYC metro north/west, and throughout at night. && .MARINE... High pressure remains over the waters tonight into Monday and drifts east late in the day into Monday night. As the high drifts east winds will increase Monday afternoon. Low level winds increase and occasional gusts to near small craft levels will be possible, mainly west of Fire Island Inlet and New York Harbor Monday afternoon into the early evening. Otherwise, winds and seas will remain below small craft levels on all the waters tonight through Monday night. Overall the pressure gradient remains weak during the long term period Tuesday through next weekend. Seas and winds are forecast to remain small craft advisory thresholds. && .HYDROLOGY... From late Monday afternoon into Monday night a few hundredths of an inch up to 2 tenths of an inch of rainfall will be possible, mainly from southwestern Connecticut into northeastern New Jersey with the highest amounts across Orange county into western Passaic county. Overall, no significant widespread rainfall expected Tuesday and through the upcoming week. The showers and thunderstorms Tuesday and Tuesday Night are forecast to produce an additional 0.15 to 0.3 inch of rain basin averaged. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JM/MET NEAR TERM...JM/MET SHORT TERM...MET LONG TERM...JM AVIATION...NV MARINE...JM/MET HYDROLOGY...JM/MET is the U.S. government's official web portal to all federal, state and local government web resources and services.