Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 272015 AFDOKX Area Forecast Discussion National Weather Service New York NY 415 PM EDT Thu Apr 27 2017 .SYNOPSIS...
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A weakening cold front approaches tonight and further weakens when it moves into the region Friday. Another cold front approaches late Friday night into Saturday. A cold front will approach on Saturday and pass through Saturday night. High pressure will return briefly for Sunday, then the front will return north as a warm front Sunday night and lift to the north on Monday. A cold front will then pass through from the west Monday night into early Tuesday, followed by weak high pressure into Wednesday. Another weak frontal system may begin to approach on Thursday.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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The main story tonight will be the southerly flow advecting in more moisture. More warm air and moisture advection will be occurring with a S-SW flow at the surface and SW flow aloft. Areas of fog will develop across the region, which especially at the coastline could become dense late. There will be a chance of showers and thunderstorms late ahead of a cold front. Showalters lower to slightly below zero conveying some elevated instability.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
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The cold front washes out across the region Friday. The more SW flow continues as the airmass will continue to get warmer. Ridging aloft occurs. Fog burns off in the morning. More sun is expected. Highs Friday in the upper 60s out east where rain showers and low clouds could linger to lower 80s for western locations where there will be more sun. A chance of showers and thunderstorms early but drier conditions move in the afternoon with more of a westerly component to wind. Next system approaches Friday night from the NW. Ridging will make it more difficult for thunder. Showers chances increase late at night into early Saturday. Lows in the low 50s to low 60s Friday night.
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&& .LONG TERM /SATURDAY THROUGH THURSDAY/...
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Forecast for this time frame remains rather consistent. First, a weakening front nearby and a passing mid level shortwave may generate some showers and possibly an elevated tstm mainly inland Sat morning. Then Bermuda type high pressure setting up over the western Atlantic will set up a favorable flow for warm temperatures on Sat, even across coastal areas, as winds shift to the southwest and then west. Have continued to trend warmer, with some places in NE NJ reaching the upper 80s, on the higher end of guidance. If the slightly warmer NAM were to verify, with full mixing to 850 mb and late day downslope flow, Newark could make a run at the first 90- degree reading of the year. Many places away from south facing shorelines should get into at least the lower 80s, with 70s along the coastlines and in the hither elevations inland. Capping inversion will keep afternoon precip at bay. A back door cold front dropping from the north should come through at night, with some showers and possibly an elevated tstm, as low levels stabilize but mid and upper levels remain marginally unstable. It will be noticeably cooler for Sunday with near average temps in the 60s. Not much change for the long term with a warm front approaching Sunday night and lifting through on Monday, accompanied by showers and possibly an elevated tstm. Temps on Mon will be above average, with upper 60s across Long Island and most of southern CT, and 70s from NYC north/west. Some showers could come in late day ahead of an approaching cold front, but the main push should come at night, with only slight chance for a tstm as instability looks rather marginal. Any remaining showers out east on Tue should end by late morning, with fair wx and temps once again slightly above average for both Tue and Wed as weak high pressure slides south, with upper 60s and lower 70s. Increasing clouds on Wed ahead of the next weak frontal system should limit high temps on Thu to the lower and mid 60s.
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&& .AVIATION /20Z THURSDAY THROUGH TUESDAY/...
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A weakening cold front approaches from the west through tonight and moves into the NYC area around 12Z Friday. The front moves slowly east of the NYC terminals and dissipates Friday morning. High pressure over the western Atlantic builds toward the southeast coast Friday morning. Variability with ceilings remains into early this evening, 00Z to 01Z, with mostly MVFR ceilings and unrestricted visibilities. Ceilings will be briefly VFR at many locations through 22Z, Then ceilings and visibilities lower back to MVFR and IFR 22Z and later. Widespread IFR to LIFR with drizzle and fog after 02Z and then remaining through tonight. An isolated thunderstorm is possible late tonight from the NYC terminals and west. Conditions improve Friday morning as the cold front moves into the terminals. Timing of the cold front and dissipation remains uncertain. Winds S to SSE 10 KT or less this afternoon into this evening, then becoming light and variable. Winds shift to west with the passage of the cold front then come back around to southwest as the front dissipates. Sea breezes are likely Friday afternoon. NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Amendments due to variability in ceilings with MVFR to briefly VFR this afternoon. Conditions lower back to IFR around 00Z. Timing of lowering conditions may be sooner than forecast. KLGA TAF Comments: Amendments due to variability in ceilings with MVFR to briefly VFR this afternoon. Conditions lower back to IFR around 00Z. Timing of lowering conditions may be sooner than forecast. KEWR TAF Comments: Amendments due to variability in ceilings with MVFR to briefly VFR this afternoon. Conditions lower back to IFR around 00Z. Timing of lowering conditions may be sooner than forecast. KTEB TAF Comments: Amendments due to variability in ceilings with MVFR to briefly VFR this afternoon. Conditions lower back to IFR around 00Z. Timing of lowering conditions may be sooner than forecast. KHPN TAF Comments: Amendments due to variability in ceilings with MVFR most likely. There may be a brief period of VFR ceilings, 3500 FT, this afternoon. Conditions lower back to IFR around 23Z. Timing of lowering conditions may be sooner than forecast. KISP TAF Comments: Amendments due to variability in ceilings with MVFR most likely. There may be a brief period of VFR ceilings, 3500 FT, this afternoon. Conditions lower back to IFR around 23Z. Timing of lowering conditions may be sooner than forecast. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .Friday afternoon-Sunday...VFR. There is a chance of isolated thunderstorms north and west of the metro terminals Saturday afternoon and evening. .Sunday night-Monday...MVFR to IFR with light rain and fog. .Monday night-Tuesday...MVFR with showers and isolated thunderstorms. Improving to VFR with a cold front passage Tuesday.
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&& .MARINE...
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SCA for ocean seas goes through Friday. Otherwise, sub SCA for other waters. The SCA will be more marginal for ocean Friday night. Dense fog redevelops tonight on the waters and lasts until late Friday morning. Fairly high confidence in increasing S-SW flow pushing ocean seas above 5 ft by Mon afternoon ahead of a cold front, with gusts up to 25 kt and seas 5-8 ft Mon night. Ocean seas over 5 ft will likely linger into Tue.
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&& .HYDROLOGY...
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Rainfall amounts tonight through Saturday morning are generally expected to remain below a quarter of an inch. However, there may be isolated brief heavy downpours in any thunderstorms that develop. Rainfall amounts with a passing cold front Mon night into early Tue morning should be 1/4 to 1/2 inch, with some locally higher amounts, No widespread hydrologic impact foreseen.
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&& .TIDES/COASTAL FLOODING... Due to high astronomical tides and an easterly swell the next couple of days, water levels may approach minor coastal flood benchmarks, in particular across the south shore back bays of western LI during the evening high tide cycle. Only 1/3 to 3/4 of a foot of surge is needed for minor flooding. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...Coastal Flood Advisory from 9 PM to 11 PM EDT this evening for NYZ075-178-179. NJ...None. MARINE...Dense Fog Advisory from 8 PM this evening to 10 AM EDT Friday for ANZ330-335-338-340-345-350-353-355. Small Craft Advisory for hazardous seas until 6 PM EDT Friday for ANZ350-353-355.
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&& $$ SYNOPSIS...Goodman/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...Goodman AVIATION...MET MARINE...Goodman/JM HYDROLOGY...Goodman/JM TIDES/COASTAL FLOODING...

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