Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 181335 AFDOKX Area Forecast Discussion National Weather Service New York NY 935 AM EDT Mon Sep 18 2017 .SYNOPSIS... High pressure building north of the region will be shunted northward through mid week as tropical cyclone Jose moves up the coast. Please refer to National Hurricane Center products for more details on Jose. High pressure begins to build into the area again by late week into the weekend. && .NEAR TERM /THROUGH TONIGHT/... Onshore flow will maintain moisture beneath a strengthening inversion as high pressure briefly builds from the north. As such, expect mostly cloudy conditions to linger through much of the day. Temperatures will be close to normal with the exception of inland areas where cloud cover and marine influence may be more limited, allowing temperatures to rise to 5 to 10 degrees above climatological normals. With long period swells allowing surf to build, dangerous beach conditions will persist today. A high risk of rip currents and high surf advisory remain in effect for Atlantic beaches. Overnight, the high will begin to shift to the north ahead of Jose, with the pressure gradient gradually strengthening on the northern fringe of the system. Expect winds to gradually increase in speed overnight, mainly across eastern Long Island and Connecticut. && .SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/... All focus for Tuesday and Tuesday night remains on tropical cyclone Jose as it moves up the coast. Fairly good consensus on the track now, with the official NHC forecast placing the center of the system offshore of the Long Island coast Tuesday night. As previously referenced, please continue to check official NHC forecasts for official information. It`s important to note that tropical storm force winds will extend well beyond the center, and that a tropical storm watch remains in effect for Long Island, Westchester County, and portions of southern Connecticut. In addition to the increasing winds, dangerous conditions will persist at area beaches, while minor to moderate coastal flooding will be possible. Rainfall will also increase overnight, particularly across the aforementioned areas where the tropical storm watch remains in effect. Refer to the hydrology and coastal flooding sections below for more information. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... Confidence is increasing in a period of tropical storm-force winds and heavy rain persisting into at least Wednesday for LI/CT. The exact track of Jose will affect the intensity of winds, rain, and coastal impacts for the region during this time period. Regardless of the uncertainty in path and intensity, confidence remains high that Jose will bring increasingly dangerous surf, widespread dune erosion (waves hitting base of dunes), and localized washovers (wave overtopping dunes) into middle of next week. Refer to the coastal flooding section for more information. Total rainfall amounts through mid week are expected to range between 1 and 4 inches, with the highest amounts across Eastern long Island and eastern CT. By late week and into the weekend, confidence in the forecast remains very low depending on the eastward progression of Jose. Although high pressure is expected to build over the area with generally dry conditions and near to above normal temperatures, coastal impacts may be slow to subside if Jose lingers farther offshore, as depicted by current NHC forecasts. Please continue to monitor NHC forecasts for official information about tropical cyclone Jose, at http:/hurricanes.gov. The NWS will continue to monitor the progression of Jose closely. Please stay tuned for subsequent updates. && .AVIATION /14Z MONDAY THROUGH FRIDAY/...
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High pressure remains in control through tonight. Jose will gradually move closer to the northeast coast late tonight into Tuesday morning. MVFR/IFR conditions will slowly improve through the morning. MVFR may linger at coastal terminals through the afternoon, but VFR is expected to prevail middle to late afternoon for city and inland terminals. IFR conditions will return tonight with showers beginning early Tuesday morning. NE flow increases to around 10 kt today. NE winds will steadily increase overnight and become gusty, especially near the coast. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Timing of improving flight categories may be off by +/- 1-2 hours. The afternoon KJFK haze potential forecast is RED...which implies slant range visibility less than 4sm outside of cloud. KLGA TAF Comments: Ceiling may fluctuate between MVFR and IFR through around 14z. Timing of improving flight categories thereafter may be off by +/- 1-2 hours. The afternoon KLGA haze potential forecast is YELLOW...which implies slant range visibility 4-6SM outside of cloud. KEWR TAF Comments:Timing of improving flight categories may be off by +/- 1-2 hours. The afternoon KEWR haze potential forecast is YELLOW...which implies slant range visibility 4-6SM outside of cloud. KTEB TAF Comments: Timing of improving flight categories may be off by +/- 1-2 hours. KHPN TAF Comments: Timing of improving flight categories may be off by +/- 1-2 hours. KISP TAF Comments: Timing of improving flight categories may be off by +/- 1-2 hours. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .Tuesday...MVFR in showers. Gusty NE winds around 20 kt inland to 25-35 kt near the coast. .Wednesday...MVFR conditions improve to VFR. Gusty N winds 30-40 kt east of the city terminals, diminishing late. .Thursday-Friday...VFR. Gusty N winds around 20 kt east of city terminals.
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&& .MARINE... Although winds will be light through today, seas will continue to build as long period swells reach the area ahead of tropical cyclone Jose. As Jose lifts north through the Western Atlantic tonight into Tuesday, seas on the ocean waters will likely build into the 10 to 15 ft range and could reach 15 to 20 ft by tomorrow. Seas near the entrance to eastern LI Sound from the ocean will also become rough and could approach the 7 to 10 ft range. Winds could start reaching SCA levels tonight, and then gale force by tomorrow as the pressure gradient tightens between Jose and high pressure over the Northeast. The conditions could extend well into Wednesday. The timing and hazards on the coastal waters will all depend on the strength and track of Jose. && .HYDROLOGY... No widespread hydrologic impacts are expected through today. Any hydrologic impacts from developing tropical cyclone Jose depend largely on forecast track and intensity. Please continue to monitor NHC and WPC forecasts for official information about Jose via: http:/hurricanes.gov and http:/www.wpc.ncep.noaa.gov && .TIDES/COASTAL FLOODING... Astronomical tides will rise through the middle of the week with the approach of a new moon. These rising water levels combined with incoming energetic swells building from Jose, will bring increasingly dangerous surf of potentially 12-16 ft by Tuesday into Wed. This will cause widespread dune erosion (waves hitting base of dunes), and localized washovers (wave overtopping dunes) into middle of next week. Minor to moderate coastal flooding potential is increasing with the greatest impacts during the late Tuesday to Wednesday timeframe. With some uncertainty in track, intensity, speed and location in the day 2-4 period, have leaned towards the higher end of Stevens and P-ETSS guidance envelope for surge forecasts. This points to potential for 2 to 3 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 3 ft inundation in our most vulnerable locations along the southern bays of southern LI/NYC and Peconic/Gardiners Bay, with generally 1 to 2 ft across other vulnerable coastal areas. Wave action on top of elevated waters levels could exacerbate impacts along the immediate shoreline. 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. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Tropical Storm Watch for CTZ007>012. NY...Tropical Storm Watch for NYZ071-078>081-177-179. Coastal Flood Watch from Tuesday evening through Wednesday afternoon for NYZ074-075-178. High Surf Advisory until 8 AM EDT Tuesday for NYZ075-080-081- 178-179. High Rip Current Risk until 8 PM EDT this evening for NYZ075- 178. NJ...Coastal Flood Watch from Tuesday evening through Wednesday afternoon for NJZ006-106-108. MARINE...Tropical Storm Watch for ANZ330-335-340-345-350-353-355. Small Craft Advisory from 6 AM to 6 PM EDT Tuesday for ANZ338.
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&& $$ SYNOPSIS...MD/DS/PW NEAR TERM...MD/PW SHORT TERM...MD/PW LONG TERM...MD AVIATION...CB/DS MARINE...MD/PW HYDROLOGY...MD/PW TIDES/COASTAL FLOODING...

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