Area Forecast Discussion
Issued by NWS Upton, NY

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004 FXUS61 KOKX 190238 AFDOKX Area Forecast Discussion National Weather Service New York NY 1038 PM EDT Mon Sep 18 2017 .SYNOPSIS... High pressure will retreat to the north tonight as tropical cyclone Jose moves up the coast. The area will then be impacted by Jose into the day on Wednesday. Weak high pressure builds over the area Thursday through early next week as Jose weakens and slowly tracks to the southeast. Please refer to National Hurricane Center products for more details on Jose. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... Mainly dry cloudy conditions will be in place this evening. Showers well offshore are forecast to start moving in late tonight but models are showing some initial weakening of these as they move onshore. Adjusted POPs for showers a few hours back compared to previous forecast. Temperatures and dewpoints are on track. High pressure will begin to retreat to the north this evening as tropical cyclone Jose approaches from the south. As the pressure gradient increases between Jose and the departing high, winds will gradually increase through the night, primarily across eastern Long Island and far southeastern Connecticut. With plenty of cloud cover, overnight lows will only fall into the mid 60s, about 5-10 degrees above normal for this time of year. With long period swells allowing surf to build, dangerous beach conditions will continue this evening. A high risk of rip currents and high surf advisory remain in effect for Atlantic beaches. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/... Tropical cyclone Jose remains the focus of the forecast through Wednesday. Models and the official NHC forecast continue to track Jose north and east along the Mid Atlantic coast, eventually passing near the 40N/70W benchmark by Wednesday morning. With the wind field not expected to expand as far west much as previously forecast, Nassau, southern Westchester, and southern Fairfield counties have been removed from the Tropical Storm Watch. Please continue to monitor NHC forecasts for official track information. In terms of sensible weather, northeasterly winds continue to increase through the day on Tuesday, with the highest winds and strongest gusts expected across eastern Long Island and southeastern Connecticut Tuesday night into Wednesday morning. At the same time, rain will overspread the area beginning during the day on Tuesday and continuing through the night before tapering off Wednesday afternoon. Several high resolution models are depicting the initial outer rain bands of Jose rotating through the area around daybreak Tuesday morning before the focus of the most persistent rainfall shifts to the eastern portion of the region closer to the center of the storm. It is important to note that tropical storm force winds and associated impacts extend well beyond the center of the storm. In addition to the winds and rain, dangerous conditions will persist along the coast, where minor to moderate coastal flooding will be possible. High surf and high risk of rip currents will be seen along the Atlantic Ocean beaches. See the hydrology and coastal flooding sections below for more information. && .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/... On the large scale, a very persistent pattern remains with a very large upper level ridge aloft across the Eastern US. The upper level jet remains well within the interior parts of Southeast Canada. Hence, the airmass remains mild and tropical in nature. At the surface, not much movement essentially in terms of high and low pressure centers, with Jose exhibiting eventual post tropical characteristics late this week into the weekend while slowing down in movement. It is forecast to meander in the Atlantic waters southeast of the region. In terms of weather, showers are forecast to taper off Wednesday evening with mainly dry conditions thereafter through the weekend. Winds will be on a downward trend as the pressure gradient weakens Wednesday night into Thursday and then remains nearly the same going through the weekend. A persistent northerly flow is expected. Highs are forecast be mainly in the upper 70s to lower 80s and lows low to mid 60s are forecast most nights with lows a little lower Thursday night and Friday night with a range more in the upper 50s to mid 60s. Rough surf with locally higher waves will be likely at the beaches during Wednesday night through Friday evening, when the ocean seas are forecast to range 7-10 ft. This will be mainly east of Fire Island Inlet due to continuous long period swell. There is a lot of uncertainty in the forecast of Jose late this week into this weekend. Subsequent forecast could very well have changes. Stay tuned for official track and intensity forecasts regarding Jose from the National Hurricane Center. && .AVIATION /03Z TUESDAY THROUGH SATURDAY/...
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High pressure remains centered over the Canadian Maritimes tngt. Jose will gradually track closer to the area but remain offshore Tue. The tafs are consistent with the latest official track of Jose. IFR conditions will develop overnight with periods of rain beginning early Tuesday morning. NE flow generally around 10 kt will steadily increase overnight. Strengthening nely winds will continue Tue. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .Tuesday Night...MVFR or lower with periods of rain. Increasing ne winds with speeds depending on the exact track of Jose. .Wednesday...MVFR or lower improves to VFR. Nly winds with speeds depending on the exact track of Jose. .Thursday-Friday...VFR. Gusty N winds around 20 kt east of city terminals. .Saturday...VFR. NE winds around 10-15 kt.
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&& .MARINE... As Jose lifts north through the Western Atlantic tonight into Tuesday, seas on the ocean waters will continue to increase, building to 10 to 15 ft by Tuesday afternoon, and 12 to 18 ft by Tuesday night. Seas near the entrance to the LI Sound from the ocean will also become rough and could approach the 7 to 10 ft range by Tuesday night. A Small Craft Advisory has been issued for the New York Harbor and the western Long Island Sound beginning Tuesday morning as sustained winds increase to 20-25 kt with gusts to 25-30 kt. Higher ocean seas at least of 5 ft are forecast Wednesday night through Saturday. Highest waves are forecast Wednesday night through Friday with 7-10 ft on the ocean. Wind gusts exceed SCA criteria with values near 25kt mainly on the ocean waters from Moriches to Montauk out 20nm while late Thursday night into Friday could have 25kt gusts spread farther west into ocean waters south of Fire Island Inlet and Eastern Long Island Sound and Eastern Long Island Bays. && .HYDROLOGY... No widespread hydrologic impacts are expected through tonight. Thereafter, rainfall amounts from Jose are expected to range from 0.75 inches in and around NYC to around 3 inches across far eastern Long Island. This could result in minor urban and poor drainage flooding, especially in any heavier rain bands. Rainfall will decrease significantly north and west of New York City. Please continue to monitor NHC and WPC forecasts for official information about Jose via: http:/ and http:/ No hydrologic problems are anticipated through the weekend with the current rainfall forecast. && .TIDES/COASTAL FLOODING... Rising water levels combined with incoming energetic swells from Jose, will bring increasingly dangerous surf of potentially 10-15 ft Tuesday and continuing into Wed. This will cause widespread dune erosion (waves hitting base of dunes), and localized washovers (wave overtopping dunes) into middle of next week. With increasing confidence in track of Jose to the se of Long Island, have leaned towards a blend of the higher end and mean of Stevens and P-ETSS guidance envelope for surge forecasts. This points to potential for 1 1/2 to 2 1/2 ft of surge during the late Tue into Wed high tides, which would result in widespread minor to moderate coastal flooding. These surge values could result in 2 to locally 3 ft inundation in our most vulnerable locations along the southern bays of LI/NYC and Peconic/Gardiners Bay, with generally 1 to locally 2 ft across other vulnerable coastal areas. Wave action on top of elevated waters levels will exacerbate impacts along the beachfront. As confidence increases in storm details over the next 24 hours, we will be able to refine these surge value and and potential coastal flood hazards/impacts further. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Tropical Storm Watch for CTZ007-008-010>012. Coastal Flood Advisory from 9 AM to noon EDT Tuesday for CTZ009. Coastal Flood Advisory from 6 PM Tuesday to 2 PM EDT Wednesday for CTZ009-010. NY...Tropical Storm Watch for NYZ078>081. Coastal Flood Advisory from 6 PM Tuesday to noon EDT Wednesday for NYZ074. Coastal Flood Advisory from 9 AM to noon EDT Tuesday for NYZ071-177. Coastal Flood Advisory from 6 PM Tuesday to 2 PM EDT Wednesday for NYZ071-177. High Surf Advisory until 6 PM EDT Wednesday for NYZ075-080-081- 178-179. Coastal Flood Warning from 6 PM Tuesday to noon EDT Wednesday for NYZ075-178-179. High Rip Current Risk through Tuesday evening for NYZ075-178- 179. Coastal Flood Advisory from 6 AM to noon EDT Tuesday for NYZ075-178-179. NJ...Coastal Flood Advisory from 6 PM Tuesday to noon EDT Wednesday for NJZ006-106-108. MARINE...Tropical Storm Watch for ANZ330-340-345-350-353-355. Small Craft Advisory from 6 AM Tuesday to 6 AM EDT Wednesday for ANZ335-338. && $$ SYNOPSIS...FEB/JM NEAR TERM...FEB/JM SHORT TERM...FEB LONG TERM...JM AVIATION...JMC MARINE...FEB/JM HYDROLOGY...FEB/JM TIDES/COASTAL FLOODING... is the U.S. government's official web portal to all federal, state and local government web resources and services.