Area Forecast Discussion
Issued by NWS Upton, NY

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832 FXUS61 KOKX 281720 AFDOKX Area Forecast Discussion National Weather Service New York NY 120 PM EDT Fri Apr 28 2017 .SYNOPSIS... A series of weak fronts cross the region today through Sunday. High pressure moves to the north of the region Sunday, shifting east by Monday with a warm front moving northward through the area by afternoon. A cold front moves through Monday night, followed by weak high pressure through Wednesday. A frontal system approaches from the southwest Thursday and moves along the coast through late week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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The cold front was weakening or has dissipated across the eastern zones, and with increasing subsidence as high pressure builds into the region skies have cleared. Temperatures have been rising a bit quicker than forecast and made adjustments, even raising highs this afternoon a degree or two inland. Coastal sections were cooler with more of a southerly flow, as local sea breezes develop.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... Much of tonight night should remain dry and warm. With dew points rising into the upper 50s and possibly into the lower 60s by7 Saturday morning, the air will feel more humid. A cold front will approach from the northwest, giving the area a chance for showers, mainly just before sunrise Saturday morning. Of particular concern is the 00Z NAM, which looks to spin up an MCS. Not totally bought into this, but needs to be monitored with further model runs. The cold front should push through late in the afternoon, however, any lift with this front weakens in the afternoon, so just a passing shower or thunderstorm is possible away from the coast. Coastal areas may not see any activity in the afternoon as marine influence keeps the atmosphere more stable here. Temperatures will be even warmer on Saturday than Friday, with highs in the upper 70s (even along much of the coast) to middle 80s (mainly in the New York City metro area). The Twin Forks of Long Island and southeast Connecticut will see highs in the upper 60s to lower 70s. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... By Sunday, an upper ridge centered off the southeast coast will build northward leading to a strengthening subsidence inversion across the area. Although there will be elevated instability, the strengthening inversion, in part due to low-level onshore flow, and lack of overall forcing for ascent should generally limit precipitation/thunderstorm chances. Onshore flow and cloud cover will limit heating, keeping temperatures near or slightly below climatological normals during the daytime, and slightly above normal for night. Onshore flow will continue into Monday morning, likely saturating lower levels and leading to increasing chances of light rain and/or drizzle. Went with a slightly slower European solution regarding the warm frontal passage, keeping the area cooler and cloudier for the earlier part of the day. The front should gradually move northward by afternoon or perhaps evening, with south flow leading to above normal temperatures across inland areas away from marine influence, and near normal elsewhere. The cold front moves through Monday night with likely rain and a chance of thunderstorms, giving way to clearing skies, gusty west winds and seasonable temperatures by Tuesday afternoon. Gusty west flow will continue into Wednesday, with cold advection offset somewhat by downsloping. Went slightly above guidance for Wednesday due to downslope component of the winds and lack of expected marine influence. By late week, a deepening area of low pressure will approach from the south with increasing chances of rain late into the work week. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/... A weakening cold front dissipates as it moves into western portions of the area this morning. High pressure then builds in from the southeast into tonight. VFR except lingering stratus and fog eastern terminals. These locales should improve by 11 am or noon, perhaps 1 pm at GON. Light and variable winds become WNW-W over western terminals and SW eastern terminals late this morning. Seabreezes likely at KJFK/KLGA/KISP and CT terminals this afternoon. Occasional gusts to around 15 kt are possible this afternoon KEWR/KTEB/KHPN, mainly after 18-19Z. These locations should settle from the W/SW. Winds become light and variable again tonight. VFR tonight with possible showers late. Low chance for patchy fog development. NY Metro Enhanced Aviation Weather Support... Detailed information...including hourly TAF wind component fcsts can be found at: http:/ KJFK TAF Comments: Amendments for wind direction changes are possible, but a seabreeze is expected by 18-19Z. KLGA TAF Comments: Amendments for wind direction changes are possible, but a seabreeze is expected by 20-21Z. KEWR TAF Comments: Amendments for wind direction forecast possible. Expect winds to become west/SW by 18-20Z. Low chance for SE seabreeze late. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: Amendments for wind direction changes possible. West/Sw winds are expected by 16-18Z. KHPN TAF Comments: Amendments are possible for low cloud forecast. Do expected VFR conditions by 15-16Z. KISP TAF Comments: Seabreeze is expected by 17-18Z. .OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY... .Saturday morning...Isolated-scattered showers with embedded thunderstorms are possible. .Saturday afternoon-Sunday...VFR. W-NW winds G15-20KT possible Saturday afternoon/evening. .Sunday night-Monday...MVFR or lower possible. SW winds G20-25KT possible Monday. .Monday night...MVFR possible along with isolated to scattered showers and thunderstorms isolated thunderstorms. LLWS possible. .Tuesday...VFR. && .MARINE... Wind waves and swells have been subsiding across the ocean waters, particularly west of Fire Island Inlet, where seas were below 5 feet. So, has cancelled the hazardous seas advisory for this zone. Seas will take time to subside east of Fire Island Inlet and will keep the advisory there. Winds and seas will remain fairly tranquil on Sunday, though isolated gusts to 25 kt will be possible during the afternoon and early evening. As winds become more southerly and increase on Monday ahead of an approaching cold front, seas will build to 5 to 9 ft Monday night. Ocean seas will linger over 5 ft into Tuesday and Wednesday as flow becomes more westerly but remains strong, with gusts to 25 kt possible, mainly during the afternoon and evening. Seas will briefly diminish Wednesday night into Thursday as weak high pressure moves though, before increasing again Thursday night ahead of an approaching area of low pressure. && .HYDROLOGY... No widespread hydrologic impacts foreseen through the next 7 days. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory for hazardous seas until 2 AM EDT Saturday for ANZ350-353. && $$ SYNOPSIS...MD/JP NEAR TERM...MET SHORT TERM...JP LONG TERM...MD AVIATION...PW MARINE...MET HYDROLOGY...MD/JP is the U.S. government's official web portal to all federal, state and local government web resources and services.