Area Forecast Discussion
Issued by NWS Upton, NY

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298 FXUS61 KOKX 281146 AFDOKX Area Forecast Discussion National Weather Service New York NY 746 AM EDT Fri Apr 28 2017 .SYNOPSIS... A series of weak fronts cross the region Friday through Saturday night. 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/... Fog, locally dense, should burn off an hour or so after sunrise this morning. A weakening cold front will cross the region and continue to weaken as it does so. Only slight chance for showers through early this morning, then dry conditions return. There may be a rumble of thunder, but not confidence is low. Temperatures will be on the warm side with a downsloping offshore northwest flow, shifting to the southwest by the afternoon. Temperatures away from the coast will reach the upper 70s to lower 80s, warmest across Northeast New Jersey. Coastal sections will be cooler with the potential for local sea breezes. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... Much of Friday night should remain dry and warm. Lows will only fall to the 50s to lower 60s. 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 /12Z 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. Conditions improving to VFR by mid morning, except by early afternoon at KGON. Light and variable/ESE-SE flow under 10 kt, gradually veers to the WNW-W over western terminals by mid morning and to the SW at eastern terminals by around midday. Seabreezes likely at KJFK/KLGA/KISP and CT terminals this afternoon. Frequent gusts to around 15 kt are possible this afternoon KEWR/KTEB/KHPN, with occasional gusts to 15 kt possible at remainder of city terminals. Winds become light and variable again tonight. 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: Timing of changes in wind speed and direction could be off +/- 1-2 hours. Isolated gusts up to 15KT possible this afternoon. KLGA TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. Isolated gusts up to 15KT possible this afternoon. KEWR TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. The afternoon KEWR haze potential forecast is green...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KHPN TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. KISP TAF Comments: Timing of changes in wind speed and direction could be off +/- 1-2 hours. .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... Dense fog early this morning will burn off by mid-morning. Scattered showers with an isolated thunderstorm will affect the ocean zones over the next hour. 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...Dense Fog Advisory until 10 AM EDT this morning for ANZ330-335- 338-340-345-350-353-355. Small Craft Advisory for hazardous seas until 2 AM EDT Saturday for ANZ350-353. Small Craft Advisory for hazardous seas until 6 PM EDT this evening for ANZ355. && $$ SYNOPSIS...MD/JP NEAR TERM...MD/JP SHORT TERM...JP LONG TERM...MD AVIATION...Maloit MARINE...MD/JP HYDROLOGY...MD/JP

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