Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 300041 AFDOKX Area Forecast Discussion National Weather Service New York NY 841 PM EDT Thu Sep 29 2016 .SYNOPSIS... High pressure over southern Quebec will maintain a moist northeast flow off the Atlantic Ocean into the weekend as low pressure spins over the Ohio Valley. The unsettled weather may continue into early next week before high pressure begins to exert its influence from the north for mid week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... The bulk of the rain is moving into NW NJ and eastern PA, with a couple of bands producing mainly trace amounts so far over NYC metro and the lower Hudson Valley. OKX sounding still shows some mid level dry air yet to be overcome, so it will take a while before appreciable rain makes it into the area especially east. In fact, once the bands over western sections move across there could be a brief lull in precip before heavier offshore bands approach NYC metro and Long Island. Earlier RAP/HRRR had a fairly good handle on this but might be a little too slow bringing the heavier rain in from offshore. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Followed the 29/12Z ECMWF deterministic run. The uncertainty remains on the intensity of the rain. With the 15Z SREF supporting rain through the period, categorical POP should work out. Not a very nice day for most! Winds will gust as high as 40 mph along the coast. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Stagnant and unsettled weather pattern continues into this weekend with stacked cutoff low pressure sitting over the Ohio valley...as western Atlantic ridging holds firm. Models indicating that the upper ridge gradually weakens and shifts south enough early next week to allow the upper low to finally start moving northeast early next week. At the surface, stacked low pressure sits over the Ohio Valley, with a stationary front running northeast from the Mid Atlantic and southeast of Long Island through the weekend. A series of weak waves running along this front will produce periods of rain this weekend. Then as the stacked low finally begins to lift northeast early next week, expect the the main moisture/lift axis to also weaken and lift NE. Lingering scattered showers could continue through early next week via cold pool instability interacting with the maritime air mass. Thereafter, potential for deep layered ridging developing for mid week as the region lies under ridging of an omega blocked pattern. The dry ridged pattern may continue into late week, but will have to monitor the evolution of Hurricane Matthew. Please refer to the National Hurricane Center forecasts for further information. Temps will likely be several degrees below seasonable Sat and possibly Sunday with cool air damming, clouds, and rainfall, then should return to near seasonable for early next week. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... Terminal area will be in between high pressure to the northeast and low pressure to the southwest into Friday afternoon. MVFR ceilings return overnight to all but KSWF and KGON where it should develop Friday morning. Light rain looks to start towards sunrise Friday, with moderate rain developing by mid-late Friday. The exception is at KGON, where light rain should hold off until around midday on Friday. NE-E winds through the TAF period, gusting to 25-35kt at city/coastal terminals and 15-25kt at inland terminals. Gusts could be intermittent at times into this evening. 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: Peak gusts could be 5kt or so higher than those in TAFs. KLGA TAF Comments: Variable ceilings between VFR and MVFR possible into this evening. Peak gusts could be 5kt or so higher than those in TAFs. KEWR TAF Comments: A chance of VFR this evening. Peak gusts could be 5kt or so higher than those in TAFs. KTEB TAF Comments: Variable ceilings between VFR and MVFR possible into this evening. Peak gusts could be 5kt or so higher than those in TAFs. KHPN TAF Comments: Variable ceilings between VFR and MVFR possible into this evening. Peak gusts could be 5kt or so higher than those in TAFs. KISP TAF Comments: Peak gusts could be 5kt or so higher than those in TAFs. .Outlook for 18Z Friday through Monday... .Friday Afternoon-Saturday...IFR/MVFR in rain. NE winds g25-35 kt Friday afternoon/evening. .Saturday Night-Sunday Night...MVFR or lower possible with showers. .Monday-Tuesday...VFR with isolated to scattered showers possible. && .MARINE... Winds increase slightly overnight into Friday Morning, thus have issued a gale warning for all waters except NY Harbor. SCA conditions expected Friday night into Saturday for the Ocean and possibly all waters, but should begin to relent Sat night into early Sunday as easterly flow weakens. Ocean seas should follow suit as well. Sub SCA conditions likely for early next week under a weak pressure gradient. && .HYDROLOGY... There is a high degree of uncertainty on the amount of rainfall through Friday. Moderate rainfall late tonight into Friday morning for western sections and the NY Metro is possible, with 1/2 to 1 inch QPF possible. Overall, totals should range in the 1-2 inch range through Saturday night. The prolonged nature of the rain event should preclude any hydrologic issues. No significant rainfall for early to mid next week. && .TIDES/COASTAL FLOODING... Water levels along the south shore of western and central Long Island, New York Harbor, and tidally affected portions of NJ should slightly exceed minor benchmarks this evening. With slight strengthening of ENE gales into the Friday morning high tide cycle, would expect surge to at least match or even slightly exceed that of tonight. With a slightly higher astronomical high tide, this should result in widespread minor coastal flooding for the above mentioned areas. NOTE: The flooding could be exacerbated if high tide coincides with heavy rain Friday morning, during the Fri morning rush. Along western Long Island sound and the eastern bays of Long Island, wind fields will be slightly weaker the next 24 hours, and may be falling off by high tide times Fri late morning, but can`t rule out localized minor coastal flooding or wave splashover in the most vulnerable northeast and east facing spots during high tide. Although wind fields weaken for Fri Evening high tide, localized minor flooding still may be a concern for the south shore of Long Island. Additionally, a persistent easterly sweep of 6 to 10 ft surf through Friday will likely result in minor to moderate beach erosion issues at the the ocean beachfront. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Coastal Flood Advisory until 11 PM EDT this evening for NYZ179. Coastal Flood Advisory from 6 AM to 11 AM EDT Friday for NYZ074-075-080-178-179. NJ...Coastal Flood Advisory from 6 AM to 11 AM EDT Friday for NJZ006-106-108. MARINE...Small Craft Advisory until 6 PM EDT Friday for ANZ338. Gale Warning until 6 PM EDT Friday for ANZ330-335-340-345-350- 353-355. && $$ SYNOPSIS...Goodman/Tongue NEAR TERM...Goodman/Tongue SHORT TERM...Tongue LONG TERM...NV AVIATION...IRD MARINE...Goodman/Tongue/NV HYDROLOGY...Goodman/Tongue/NV TIDES/COASTAL FLOODING...NV

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