974 FXUS61 KOKX 211151 AFDOKX Area Forecast Discussion National Weather Service New York NY 751 AM EDT Sat Aug 21 2021 .SYNOPSIS... Henri in the Atlantic will be moving northward tonight with impacts likely across parts of the local area starting as early as overnight tonight through Monday. A surface disturbance will be in the vicinity Monday night and Tuesday. A frontal boundary will remain to the north and west of the forecast area through the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Upper level ridge over Quebec shifts over main throughout the day. Further south the upper level trough centered over southern Pennsylvania pulls moisture northward in the mid and upper levels from Tropical Storm Henri. Increased cloudiness through the day is expected as the stationary boundary along the coast begins to shift north as a warm front. Typical summer time temperatures expected with highs in the 80s by the afternoon. Be advised, preparations for the arrival of Henri should be completed prior to nightfall. There will be a high risk of rip currents for Today. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/... Strong onshore flow develops in advance of T.C. Henri, with lingering cloud cover and a humid air mass across the area. Outer band showers and isolated thunderstorms will be possible as the night progresses with conditions rapidly deteriorating as winds increase throughout the night. Timing of the onset of worsening conditions could vary with the anticipated forward speed of Henri. Continue to refer to the National Hurricane Center for forecast of track and time of tropical wind speed arrival. && .LONG TERM /SUNDAY THROUGH FRIDAY/... **HURRICANE CONDITIONS EXPECTED ACROSS PORTIONS OF LONG ISLAND AND SOUTHERN CONNECTICUT** The main focus continues to be with Henri which is currently 605 miles south of Montauk Point and will likely track north across Long Island and into southern New England Sunday as a Category 1 Hurricane. Please refer to the National Hurricane Center for the official forecast track information. Please refer to the Hurricane Local Statement for potential impacts. The latest forecast track takes the center of Henri across eastern Long Island and then towards southern Connecticut on Sunday. The ultimate track of Henri will determine where the strongest winds occur and the amount of rainfall. Tropical storm or hurricane force winds are expected along the south shore, eastern Long Island and across southeast Connecticut. Given the latest track, the heaviest rainfall looks to occur across Long Island and southern Connecticut, along and west of the center of the low. The cyclone may begin interacting with an upper level shortwave over the Middle Atlantic coast, which could enhance rainfall on the western side of the storm. Storm surge inundation is also a concern and there is potential for life-threatening storm surge along the immediate shore of Long Island, Southern Connecticut, and the Western Sound. The timeline of impacts looks to be Sunday morning through Sunday evening, with the storm weakening as it moves northward. An upper level trough will be over the area Monday night and slowly track eastward, pushing off the coast by late Monday night into early Tuesday morning. This will mean a slight chance for showers Monday night. Not looking at anything widespread as an associated surface trough will be in nearly the same position as the upper trough, precluding any strengthening of the system. With the trough off shore for Tuesday into Wednesday morning, dry conditions will persist through then. A frontal boundary then remains to the north and west of the region through next Friday. There may be an upper level trough that approaches from the west on Wednesday, that could set off a shower or thunderstorm in the afternoon, but much of any activity should remain to the west. The best chances for any showers and thunderstorms comes towards the end of the week, as the cold front makes some progress toward the east. Temperatures will be warm on Tuesday. Ridging aloft with some height rises on Wednesday will mean continued warm conditions, leading to temperatures in the middle 80s to lower 90s on both days. With humid conditions in place (dew points in the upper 60s to lower 70s), heat index values across the forecast area could reach the middle to upper 90s. Slightly more clouds towards the end of the week will mean slightly lower temperature for Thursday and Friday. && .AVIATION /12Z SATURDAY THROUGH WEDNESDAY/... A weak frontal boundary will remains in the vicinity today. Tropical Cyclone Henri approaches tonight and reaches the area on Sun. Mainly VFR today. Some sct shwrs could produce periods of MVFR or lower at times today, but coverage and timing is too low to include sub VFR attm. Heavier rain bands move in overnight into Sunday, with IFR. Light and variable winds become SE this morning with speeds 10kt or less. Winds increase gradually tngt into Sun. Direction and speed dependent on the exact track of Henri. Winds in the TAF are based on the official Hurricane Center data. ...Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments may be needed for wind direction and impact of shwrs today. The Newark, JFK, and LaGuardia afternoon haze forecast is MODERATE (YELLOW). .OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY... .Sunday...IMPACTS EXPECTED FROM TROPICAL CYCLONE HENRI. .Monday...Mainly VFR. Chance of showers and slight chance of thunderstorms. .Tuesday...VFR. .Wednesday...VFR. Slight chance of thunderstorms in the afternoon. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... Initially sub-SCA conditions through today, before dangerous conditions develop on the waters late tonight through Sunday due to Henri. Hurricane Warnings have been issued for the eastern waters, Tropical Storm Warnings for the western sound ,western ocean, and the NY Harbor. Conditions should begin to improve Sunday night into Monday. Please refer to the National Hurricane Center for the official forecast track information. Seas will still be elevated for the eastern ocean zone Monday night, with 5 ft waves expected. However, waves will be diminishing and should fall below 5 ft after midnight. With a lack of a strong pressure gradient, winds and waves should remain below SCA criteria from Tuesday through Friday. && .HYDROLOGY... A Flood Watch has be issued for the entire area tonight through Monday morning.Hydrologic impacts Sun-Mon will depend on the track and intensity of Henri. There is the potential of 3-6 inches of rainfall late Saturday night through Sunday night across Long Island and Connecticut and 1-2 inches further west. Locally higher amounts are possible. Flash flooding is possible, especially across Long Island and Connecticut. No hydrologic impacts are expected Tue-Thu. && .TIDES/COASTAL FLOODING... There is potential for life threatening storm surge from Henri across portions of the Long Island coast and southern Connecticut coast Sunday. Storm surge warnings are in effect. Dangerous rip currents are expected on Today and Sunday due to Tropical System Henri. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Storm Surge Warning for CTZ009>012. Hurricane Warning for CTZ006>008-010>012. Flood Watch from this evening through Monday morning for CTZ005>012. Tropical Storm Warning for CTZ005-009. NY...Storm Surge Warning for NYZ071-073-078-079-081-176-177. Hurricane Warning for NYZ078>081. Flood Watch from this evening through Monday morning for NYZ067>075-078>081-176>179. Tropical Storm Warning for NYZ070>075-176>179. High Rip Current Risk through Sunday evening for NYZ075-080- 081-178-179. Storm Surge Watch for NYZ080-179. NJ...Flood Watch from this evening through Monday morning for NJZ002-004-006-103>108. Tropical Storm Warning for NJZ006-104-106-108. MARINE...Hurricane Warning for ANZ331-332-340-345-350-353. Tropical Storm Warning for ANZ335-338-355. && $$ SYNOPSIS...DJ/JP/MET NEAR TERM...DJ SHORT TERM...DJ LONG TERM...JP AVIATION...BC/JMC MARINE...JP HYDROLOGY...DS TIDES/COASTAL FLOODING...